Cell Parts and Its Functions

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    Animal cell

    Animal cells are typical of the eukaryotic cell, enclosed by a plasma membrane and containing a

    membrane-bound nucleus and organelles. Unlike the eukaryotic cells of plants and fungi, animal cells do

    not have a cell wall. This feature was lost in the distant past by the single-celled organisms that gave riseto the kingdom Animalia. Most cells, both animal and plant, range in size between 1 and 100

    micrometers and are thus visible only with the aid of a microscope.

    The lack of a rigid cell wall allowed animals to develop a greater diversity of cell types, tissues, and

    organs. Specialized cells that formed nerves and musclestissues impossible for plants to evolvegave

    these organisms mobility. The ability to move about by the use of specialized muscle tissues is a

    hallmark of the animal world, though a few animals, primarily sponges, do not possess differentiated

    tissues. Notably, protozoans locomote, but it is only via nonmuscular means, in effect, using cilia,

    flagella, and pseudopodia.

    Most animal cells are diploid, meaning that their chromosomes exist in homologous pairs. Different

    chromosomal ploidies are also, however, known to occasionally occur. The proliferation of animal cells

    occurs in a variety of ways. In instances of sexual reproduction, the cellular process ofmeiosis is first

    necessary so that haploid daughter cells, orgametes, can be produced. Two haploid cells then fuse to

    form a diploid zygote, which develops into a new organism as its cells divide and multiply.

    http://micro.magnet.fsu.edu/cells/animals/animalmodel.html
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    CELL PARTS AND ITS FUNCTIONS

    CENTRIOLES DESCRIPTION FUNCTION

    Are cylindrical structures that are

    composed of groupings

    ofmicrotubules arranged in a 9 +

    3 pattern. The pattern is so

    named because a ring of nine

    microtubule "triplets" are

    arranged at right angles to one

    another. They are found

    in animal cells.

    Centrioles help to organize the

    assembly of microtubules

    during cell division. They

    replicate during

    the interphase stage

    ofmitosis and meiosis. It is also

    called basal bodies form cilia

    and flagella.

    GOLGI BODY

    The Golgi apparatus (GA), also

    called Golgi body or Golgi complex

    and found universally in both plant

    and animal cells, is typically

    comprised of a series of five toeight cup-shaped, membrane-

    covered sacs called cisternae that

    look something like a stack of

    deflated balloons. In some

    unicellular flagellates, however, as

    many as 60 cisternae may combine

    to make up the Golgi apparatus.

    The Golgi apparatus is often

    considered the distribution and

    shipping department for the cell's

    chemical products. It modifies

    proteins and lipids (fats) thathave been built in the

    endoplasmic reticulum and

    prepares them for export outside

    of the cell or for transport to

    other locations in the cell.

    http://biology.about.com/od/mitosisglossary/g/microtubules.htmhttp://biology.about.com/od/cellbiology/ss/animal_cells.htmhttp://biology.about.com/od/mitosis/ig/Mitosis-Image-Gallery/Interphase.htmhttp://biology.about.com/od/mitosis/ss/mitosisstep.htmhttp://biology.about.com/od/meiosis/ss/meiosisstep.htmhttp://biology.about.com/od/cellanatomy/a/aa050208a.htmhttp://biology.about.com/od/cellanatomy/a/aa050208a.htmhttp://biology.about.com/od/cellanatomy/a/aa050208a.htmhttp://biology.about.com/od/cellanatomy/a/aa050208a.htmhttp://biology.about.com/od/meiosis/ss/meiosisstep.htmhttp://biology.about.com/od/mitosis/ss/mitosisstep.htmhttp://biology.about.com/od/mitosis/ig/Mitosis-Image-Gallery/Interphase.htmhttp://biology.about.com/od/cellbiology/ss/animal_cells.htmhttp://biology.about.com/od/mitosisglossary/g/microtubules.htm
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    LYSOSOMES Lysosomes are

    cellular organelles that contain

    acid hydrolase enzymes to break

    down waste materials and cellular

    debris. These enzymes are

    typically hydrolytic and can digest

    cellular macromolecules.

    They are made by the

    endoplasmic reticulum and Golgi

    complex. They are more than

    likely formed by budding from the

    "shipping" department of a Golgi

    complex. They are found in animal

    cells, while in yeast and plants the

    same roles are performed by lytic

    vacuoles.

    The name lysosome derives from

    the Greek words lysis to

    separate and soma body. They

    are frequently nicknamed

    "suicide-bags" or "suicide-sacs" by

    cell biologists due to their role

    in autolysis

    Lysosomes digest excess or

    worn-out organelles, food

    particles, and

    engulfviruses or bacteria.

    The membrane around a

    lysosome allows the digestive

    enzymes to work at the

    4.5 pH they require. Lysosomes

    fuse with vacuoles and dispense

    their enzymes into the vacuoles,

    digesting their contents.

    CILIA AND FLAGELLA Cilia and flagella are motile

    cellular appendages found in mostmicroorganisms and animals, but

    not in higher plants. cilia and

    flagella are essential for the

    locomotion of individual

    organisms. Protozoans belonging

    to the phylum Ciliophora are

    covered with cilia, while flagella

    are a characteristic of the

    protozoan group Mastigophora.

    In multicellular organisms, cilia

    function to move a cell or groupof cells or to help transport fluid

    or materials past them. Among

    other tasks, cilia also generate

    water currents to carry food and

    oxygen past the gills of clams

    and transport food through the

    digestive systems of snails.

    Flagella are found primarily on

    gametes, but create the water

    currents necessary for

    respiration and circulation in

    sponges and coelenterates as

    well.

    http://en.wikipedia.org/wiki/Organellehttp://en.wikipedia.org/wiki/Hydrolasehttp://www.bio-medicine.org/biology-definition/Hydrolytic_enzyme/http://biology.about.com/library/weekly/aa041300a.htmhttp://biology.about.com/library/weekly/aa042000a.htmhttp://biology.about.com/library/weekly/aa042000a.htmhttp://en.wikipedia.org/wiki/Vacuolehttp://en.wikipedia.org/wiki/Autolysishttp://en.wikipedia.org/wiki/Organellehttp://en.wikipedia.org/wiki/Virushttp://en.wikipedia.org/wiki/Bacteriahttp://en.wikipedia.org/wiki/Biological_membranehttp://en.wikipedia.org/wiki/Digestive_enzymehttp://en.wikipedia.org/wiki/Digestive_enzymehttp://en.wikipedia.org/wiki/PHhttp://en.wikipedia.org/wiki/Vacuolehttp://en.wikipedia.org/wiki/Vacuolehttp://en.wikipedia.org/wiki/Vacuolehttp://en.wikipedia.org/wiki/Vacuolehttp://en.wikipedia.org/wiki/PHhttp://en.wikipedia.org/wiki/Digestive_enzymehttp://en.wikipedia.org/wiki/Digestive_enzymehttp://en.wikipedia.org/wiki/Biological_membranehttp://en.wikipedia.org/wiki/Bacteriahttp://en.wikipedia.org/wiki/Virushttp://en.wikipedia.org/wiki/Organellehttp://en.wikipedia.org/wiki/Autolysishttp://en.wikipedia.org/wiki/Vacuolehttp://biology.about.com/library/weekly/aa042000a.htmhttp://biology.about.com/library/weekly/aa042000a.htmhttp://biology.about.com/library/weekly/aa041300a.htmhttp://www.bio-medicine.org/biology-definition/Hydrolytic_enzyme/http://en.wikipedia.org/wiki/Hydrolasehttp://en.wikipedia.org/wiki/Organelle
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    ENDOPLASMIC RETICULUM The endoplasmic reticulum (ER) is

    a network of flattened sacs and

    branching tubules that extends

    throughout the cytoplasm in plant

    and animal cells. These sacs and

    tubules are all interconnected by a

    single continuous membrane so

    that the organelle has only one

    large, highly convoluted and

    complexly

    arranged lumen (internal space).

    rough endoplasmic reticulum -

    (rough ER) a vast system of

    interconnected, membranous,

    infolded and convoluted sacks that

    are located in the cell's cytoplasm(the ER is continuous with the outer

    nuclear membrane). Rough ER is

    covered with ribosomes that give it

    a rough appearance. Rough ER

    transports materials through the

    cell and produces proteins in sacks

    called cisternae (which are sent to

    the Golgi body, or inserted into the

    cell membrane).

    smooth endoplasmic reticulum -

    (smooth ER) a vast system of

    interconnected, membranous,infolded and convoluted tubes that

    are located in the cell's cytoplasm

    (the ER is continuous with the outer

    nuclear membrane). The space

    within the ER is called the ER lumen.

    Smooth ER transports materials

    through the cell. It contains

    enzymes and produces and digests

    lipids (fats) and membrane proteins;

    smooth ER buds off from rough ER,

    moving the newly-made proteins

    and lipids to the Golgi body,lysosomes, and membranes.

    The endoplasmic reticulum

    manufactures, processes, and

    transports a wide variety of

    biochemical compounds for use

    inside and outside of the cell.

    Consequently, many of the

    proteins found in the cisternal

    space of the endoplasmic

    reticulum lumen are there only

    transiently as they pass on their

    way to other locations. Other

    proteins, however, are targeted

    to constantly remain in the

    lumen and are known as

    endoplasmic reticulum resident

    proteins. These special proteins,

    which are necessary for theendoplasmic reticulum to carry

    out its normal functions, contain

    a specialized retention signal

    consisting of a specific sequence

    of amino acids that enables

    them to be retained by the

    organelle.

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    ENDOSOMES AND ENDOCYTOSIS Endosomes are membrane-bound

    vesicles, formed via a complex

    family of processes collectively

    known as endocytosis, and found

    in the cytoplasm of virtually everyanimal cell. The basic mechanism

    of endocytosis is the reverse of

    what occurs during exocytosis or

    cellular secretion.

    It involves the invagination

    (folding inward) of a cells

    plasma membrane to surround

    macromolecules or other matter

    diffusing through the

    extracellular fluid

    MICROFILAMENTS

    These filaments are primarily

    structural in function and are an

    important component of the

    cytoskeleton. Microfilaments are

    solid rods made of a protein

    known as actin.

    They are involved in muscle

    contraction and with other types

    of intracellular movements. They

    help form the cells cytoskeleton,

    cilia and flagella if present.

    INTERMEDIATE FILAMENTS Intermediate filaments are a very

    broad class of fibrous proteins

    that play an important role as

    both structural and functional

    elements of the cytoskeleton.

    Ranging in size from 8 to 12

    nanometers.

    Intermediate filaments function as

    tension-bearing elements to help

    maintain cell shape and rigidity,

    and serve to anchor in place

    several organelles, including the

    nucleus and desmosomes.

    Intermediate filaments are also

    involved in formation ofthe nuclear lamina, a net-like

    meshwork array that lines the

    inner nuclear membrane and

    governs the shape of the nucleus.

    The stable cytoskeletal elements

    resist mechanical forces acting on

    the cell.

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    MICROTUBULES

    Are cylindrical structures made up

    of tubulin proteins. These straight,

    hollow cylinders are found

    throughout the cytoplasm of all

    eukaryotic cells (prokaryotes don't

    have them) and carry out a variety

    of functions, ranging from

    transport to structural support.

    Microtubules, which are about 25

    nanometers in diameter, form

    part of the cytoskeleton.

    It gives structure and shape to a

    cell, and also serve as conveyor

    belts moving other organelles

    throughout the cytoplasm. In

    addition, microtubules are the

    major components of cilia and

    flagella, and participate in the

    formation of spindle fibers

    during cell division (mitosis).

    They are involved in intracellular

    and cellular movements and

    form centrioles.

    MITOCHONDRIA Spherical to rod-shaped organelles

    with a double membrane. The

    inner membrane is infolded many

    times, forming a series of

    projections (called cristae).

    Mitochondria are generally oblong

    organelles, which range in sizebetween 1 and 10 micrometers in

    length, and occur in numbers that

    directly correlate with the cell's

    level of metabolic activity. The

    word mitochondrion comes from

    the Greek word mitosthread

    or chondrion granule.

    Mitochondria are sometimes

    described as "cellular power

    plants" because they generate

    most of the cell's supply

    ofadenosine triphosphate (ATP),

    used as a source ofchemical

    energy. mitochondria areinvolved in a range of other

    processes, such

    as signaling, cellular

    differentiation, cell death, as well

    as the control of the cell

    cycle and cell growth

    Mitochondria have been

    implicated in several human

    diseases, including mitochondrial

    disorders and cardiac

    dysfunction and may play a role

    in the aging process.

    http://en.wikipedia.org/wiki/Adenosine_triphosphatehttp://en.wikipedia.org/wiki/Chemical_energyhttp://en.wikipedia.org/wiki/Chemical_energyhttp://en.wikipedia.org/wiki/Cell_signalinghttp://en.wikipedia.org/wiki/Cellular_differentiationhttp://en.wikipedia.org/wiki/Cellular_differentiationhttp://en.wikipedia.org/wiki/Apoptosishttp://en.wikipedia.org/wiki/Cell_cyclehttp://en.wikipedia.org/wiki/Cell_cyclehttp://en.wikipedia.org/wiki/Cell_growthhttp://en.wikipedia.org/wiki/Mitochondrial_disordershttp://en.wikipedia.org/wiki/Mitochondrial_disordershttp://en.wikipedia.org/wiki/Aging_processhttp://en.wikipedia.org/wiki/Aging_processhttp://en.wikipedia.org/wiki/Mitochondrial_disordershttp://en.wikipedia.org/wiki/Mitochondrial_disordershttp://en.wikipedia.org/wiki/Cell_growthhttp://en.wikipedia.org/wiki/Cell_cyclehttp://en.wikipedia.org/wiki/Cell_cyclehttp://en.wikipedia.org/wiki/Apoptosishttp://en.wikipedia.org/wiki/Cellular_differentiationhttp://en.wikipedia.org/wiki/Cellular_differentiationhttp://en.wikipedia.org/wiki/Cell_signalinghttp://en.wikipedia.org/wiki/Chemical_energyhttp://en.wikipedia.org/wiki/Chemical_energyhttp://en.wikipedia.org/wiki/Adenosine_triphosphate
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    NUCLEUS From Latin nucleus or nuculeus,

    meaning kernel. Itis a membrane

    -enclosed organelle found

    in eukaryotic cells. It contains

    most of the cell's genetic material,

    organized as multiple longlinear DNA molecules in complex

    with a large variety ofproteins,

    such as histones, to

    form chromosomes.

    The genes within these

    chromosomes are the cell's

    nuclear genome.

    The function of the nucleus is to

    maintain the integrity of these

    genes and to control the

    activities of the cell by regulating

    gene expression the nucleus is,

    therefore, the control center ofthe cell. The main structures

    making up the nucleus are

    the nuclear envelope, a triple cell

    membrane and membrane that

    encloses the entire organelle and

    unifies its contents from the

    cellular cytoplasm, and

    the nucleoskeleton (which

    includes nuclear lamina), a

    meshwork within the nucleus

    that adds mechanical support,

    much like the cytoskeleton,

    which supports the cell as a

    whole.

    PEROXISOME Microbodies are a diverse group

    of organelles that are found in the

    cytoplasm, roughly spherical and

    bound by a single membrane.

    There are several types of

    microbodies but peroxisomes arethe most common. Peroxisomes

    are similar in appearance to

    lysosomes, another type of

    microbody, but the two have very

    different origins.

    Peroxisomes contain a variety of

    enzymes, which primarily

    function together to rid the cell

    of toxic substances, and in

    particular, hydrogen peroxide (a

    common byproduct of cellularmetabolism). These organelles

    contain enzymes that convert the

    hydrogen peroxide to water,

    rendering the potentially toxic

    substance safe for release back

    into the cell. Some types of

    peroxisomes, such as those in

    liver cells, detoxify alcohol and

    other harmful compounds by

    transferring hydrogen from the

    poisons to molecules of oxygen(a process termed oxidation).

    http://en.wikipedia.org/wiki/Latinhttp://en.wikipedia.org/wiki/Organellehttp://en.wikipedia.org/wiki/Eukaryotehttp://en.wikipedia.org/wiki/Cell_(biology)http://en.wikipedia.org/wiki/Geneticshttp://en.wikipedia.org/wiki/DNAhttp://en.wikipedia.org/wiki/Proteinhttp://en.wikipedia.org/wiki/Histonehttp://en.wikipedia.org/wiki/Chromosomehttp://en.wikipedia.org/wiki/Genehttp://en.wikipedia.org/wiki/Genomehttp://en.wikipedia.org/wiki/Gene_expressionhttp://en.wikipedia.org/wiki/Nuclear_envelopehttp://en.wikipedia.org/w/index.php?title=Wall_membrane&action=edit&redlink=1http://en.wikipedia.org/w/index.php?title=Wall_membrane&action=edit&redlink=1http://en.wikipedia.org/wiki/Cytoplasmhttp://en.wikipedia.org/w/index.php?title=Nucleoskeleton&action=edit&redlink=1http://en.wikipedia.org/wiki/Nuclear_laminahttp://en.wikipedia.org/wiki/Cytoskeletonhttp://en.wikipedia.org/wiki/Cytoskeletonhttp://en.wikipedia.org/wiki/Nuclear_laminahttp://en.wikipedia.org/w/index.php?title=Nucleoskeleton&action=edit&redlink=1http://en.wikipedia.org/wiki/Cytoplasmhttp://en.wikipedia.org/w/index.php?title=Wall_membrane&action=edit&redlink=1http://en.wikipedia.org/w/index.php?title=Wall_membrane&action=edit&redlink=1http://en.wikipedia.org/wiki/Nuclear_envelopehttp://en.wikipedia.org/wiki/Gene_expressionhttp://en.wikipedia.org/wiki/Genomehttp://en.wikipedia.org/wiki/Genehttp://en.wikipedia.org/wiki/Chromosomehttp://en.wikipedia.org/wiki/Histonehttp://en.wikipedia.org/wiki/Proteinhttp://en.wikipedia.org/wiki/DNAhttp://en.wikipedia.org/wiki/Geneticshttp://en.wikipedia.org/wiki/Cell_(biology)http://en.wikipedia.org/wiki/Eukaryotehttp://en.wikipedia.org/wiki/Organellehttp://en.wikipedia.org/wiki/Latin
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    PLASMA MEMBRANE

    The cell membrane or plasma

    membrane is a biological

    membrane that separates

    the interior of all cells from

    the outside environment.[1]

    The

    cell membrane is selectively

    permeable to ions and organic

    molecules and controls the

    movement of substances in and

    out of cells. It consists of the lipid

    bilayer with embedded proteins.

    The membrane acts as a boundary,

    holding the cell constituents

    together and keeping other

    substances from entering. The

    plasma membrane is permeable to

    specific molecules, however, and

    allows nutrients and other

    essential elements to enter the cell

    and waste materials to leave the

    cell. Small molecules, such as

    oxygen, carbon dioxide, and water,

    are able to pass freely across the

    membrane, but the passage of

    larger molecules, such as amino

    acids and sugars, is carefully

    regulated. Cell membranes are

    involved in a variety of cellular

    processes such ascell adhesion, ion

    conductivity and cell signaling and

    serve as the attachment surface

    for several extracellular structures,

    including the cell wall, glycocalyx,

    and intracellular cytoskeleton.

    RIBOSOMES Ribosomes are mainly found

    bound to the endoplasmicreticulum and the nuclear

    envelope, as well as freely

    scattered throughout the

    cytoplasm, depending upon

    whether the cell is plant, animal,

    or bacteria.

    Ribosomes assemble the twenty

    specific amino acid molecules toform the

    particular protein molecule

    determined by

    the nucleotide sequence of

    an RNA molecule. The organelles

    serve as the protein production

    machinery for the cell and are

    consequently most abundant in

    cells that are active in protein

    synthesis, such as pancreas and

    brain cells.

    http://en.wikipedia.org/wiki/Biological_membranehttp://en.wikipedia.org/wiki/Biological_membranehttp://en.wikipedia.org/wiki/Cytoplasmhttp://en.wikipedia.org/wiki/Extracellular_spacehttp://en.wikipedia.org/wiki/Plasma_membrane#cite_note-0http://en.wikipedia.org/wiki/Plasma_membrane#cite_note-0http://en.wikipedia.org/wiki/Plasma_membrane#cite_note-0http://en.wikipedia.org/wiki/Semipermeable_membranehttp://en.wikipedia.org/wiki/Semipermeable_membranehttp://en.wikipedia.org/wiki/Lipid_bilayerhttp://en.wikipedia.org/wiki/Lipid_bilayerhttp://en.wikipedia.org/wiki/Proteinhttp://en.wikipedia.org/wiki/Cell_adhesionhttp://en.wikipedia.org/wiki/Ion_conductivityhttp://en.wikipedia.org/wiki/Ion_conductivityhttp://en.wikipedia.org/wiki/Cell_signalinghttp://en.wikipedia.org/wiki/Cell_wallhttp://en.wikipedia.org/wiki/Glycocalyxhttp://en.wikipedia.org/wiki/Cytoskeletonhttp://en.wikipedia.org/wiki/Amino_acidhttp://en.wikipedia.org/wiki/Nucleotidehttp://en.wikipedia.org/wiki/RNAhttp://en.wikipedia.org/wiki/RNAhttp://en.wikipedia.org/wiki/Nucleotidehttp://en.wikipedia.org/wiki/Amino_acidhttp://en.wikipedia.org/wiki/Cytoskeletonhttp://en.wikipedia.org/wiki/Glycocalyxhttp://en.wikipedia.org/wiki/Cell_wallhttp://en.wikipedia.org/wiki/Cell_signalinghttp://en.wikipedia.org/wiki/Ion_conductivityhttp://en.wikipedia.org/wiki/Ion_conductivityhttp://en.wikipedia.org/wiki/Cell_adhesionhttp://en.wikipedia.org/wiki/Proteinhttp://en.wikipedia.org/wiki/Lipid_bilayerhttp://en.wikipedia.org/wiki/Lipid_bilayerhttp://en.wikipedia.org/wiki/Semipermeable_membranehttp://en.wikipedia.org/wiki/Semipermeable_membranehttp://en.wikipedia.org/wiki/Plasma_membrane#cite_note-0http://en.wikipedia.org/wiki/Extracellular_spacehttp://en.wikipedia.org/wiki/Cytoplasmhttp://en.wikipedia.org/wiki/Biological_membranehttp://en.wikipedia.org/wiki/Biological_membrane
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    NUCLEOLUS

    The nucleolus (plural nucleoli) is a

    non-membrane bound structure.

    an organelle within the nucleus -

    composed of proteins and nucleic

    acids found within

    the nucleus. Ribosomal

    RNA (rRNA) istranscribed andassembled within the nucleolus.

    It is where ribosomal RNA is

    produced.

    CYTOPLASM The cytoplasm is a small gel-like

    substance residing between

    the cell membrane holding all

    the cell's internal sub-structures

    (called organelles), except for the

    nucleus. All the contents of the

    cells ofprokaryote organisms

    (which lack a cell nucleus) are

    contained within the cytoplasm.

    Within the cells ofeukaryote

    organisms the contents of the cell

    nucleus are separated from the

    cytoplasm, and are then called

    the nucleoplasm.

    It is within the cytoplasm that

    most cellular activities occur,

    such as many metabolic

    pathways including glycolysis,

    and processes such as cell

    division.

    VACUOLE Fluid-filled, membrane-surrounded

    cavities inside a cell. Vacuoles are

    essentially enclosed compartments

    which are filled with water

    containing inorganic and organic

    molecules including

    enzymes in solution, though in

    certain cases they may contain

    solids which have been engulfed.

    Vacuoles are formed by the fusion

    of multiple membrane vesicles and

    are effectively just larger forms of

    these.

    The vacuole fills with food being

    digested and waste material that

    is on its way out of the cell.

    http://en.wikipedia.org/wiki/Cell_nucleushttp://en.wikipedia.org/wiki/Ribosomal_RNAhttp://en.wikipedia.org/wiki/Ribosomal_RNAhttp://en.wikipedia.org/wiki/Transcription_(genetics)http://en.wikipedia.org/wiki/Cell_membranehttp://en.wikipedia.org/wiki/Cell_(biology)http://en.wikipedia.org/wiki/Organellehttp://en.wikipedia.org/wiki/Cell_nucleushttp://en.wikipedia.org/wiki/Prokaryotehttp://en.wikipedia.org/wiki/Cell_nucleushttp://en.wikipedia.org/wiki/Eukaryotehttp://en.wikipedia.org/wiki/Cell_nucleushttp://en.wikipedia.org/wiki/Cell_nucleushttp://en.wikipedia.org/wiki/Nucleoplasmhttp://en.wikipedia.org/wiki/Metabolic_pathwayhttp://en.wikipedia.org/wiki/Metabolic_pathwayhttp://en.wikipedia.org/wiki/Glycolysishttp://en.wikipedia.org/wiki/Cell_divisionhttp://en.wikipedia.org/wiki/Cell_divisionhttp://en.wikipedia.org/wiki/Enzymeshttp://en.wikipedia.org/wiki/Soluteshttp://en.wikipedia.org/wiki/Vesicle_(biology)http://en.wikipedia.org/wiki/Vesicle_(biology)http://en.wikipedia.org/wiki/Soluteshttp://en.wikipedia.org/wiki/Enzymeshttp://en.wikipedia.org/wiki/Cell_divisionhttp://en.wikipedia.org/wiki/Cell_divisionhttp://en.wikipedia.org/wiki/Glycolysishttp://en.wikipedia.org/wiki/Metabolic_pathwayhttp://en.wikipedia.org/wiki/Metabolic_pathwayhttp://en.wikipedia.org/wiki/Nucleoplasmhttp://en.wikipedia.org/wiki/Cell_nucleushttp://en.wikipedia.org/wiki/Cell_nucleushttp://en.wikipedia.org/wiki/Eukaryotehttp://en.wikipedia.org/wiki/Cell_nucleushttp://en.wikipedia.org/wiki/Prokaryotehttp://en.wikipedia.org/wiki/Cell_nucleushttp://en.wikipedia.org/wiki/Organellehttp://en.wikipedia.org/wiki/Cell_(biology)http://en.wikipedia.org/wiki/Cell_membranehttp://en.wikipedia.org/wiki/Transcription_(genetics)http://en.wikipedia.org/wiki/Ribosomal_RNAhttp://en.wikipedia.org/wiki/Ribosomal_RNAhttp://en.wikipedia.org/wiki/Cell_nucleus
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    NUCLEAR PORE

    NUCLEAR ENVELOPE

    Nuclear pores are

    large protein complexes that cross

    the nuclear envelope, which is the

    double membrane surrounding

    the eukaryotic cell nucleus. There

    are about on average 2000

    nuclear pore complexes in the

    nuclear envelope of a vertebrate

    cell, but it varies depending on cell

    type and the stage in the life cycle.

    The proteins that make up the

    nuclear pore complex are known

    as nucleoporins.

    A nuclear envelope (NE) (also

    known as the perinuclear

    envelope, nuclear

    membrane, nucleolemma or karyo

    theca). Is a double-membrane

    structure that is pierced by thepores.

    Nuclear pore complexes allow

    the transport of water-soluble

    molecules across the nuclear

    envelope. This transport

    includes RNA and ribosomes

    moving from nucleus to the

    cytoplasm and proteins (such

    as DNA

    polymerase and lamins), carbohy

    drates, signal

    molecules and lipids moving into

    the nucleus. It is notable that

    the nuclear pore complex(NPC)

    can actively conduct 1000

    translocations per complex per

    second.

    Is a double lipid bilayer that

    encloses the genetic material

    ineukaryotic cells. The nuclear

    envelope also serves as the

    physical barrier, separating the

    contents of the nucleus (DNA in

    particular) from

    the cytosol (cytoplasm).Many nuclear pores are inserted

    in the nuclear envelope, which

    facilitate and regulate the

    exchange of materials

    (proteins such as transcription

    factors, and RNA) between the

    nucleus and the cytoplasm.

    http://en.wikipedia.org/wiki/Proteinhttp://en.wikipedia.org/wiki/Nuclear_envelopehttp://en.wikipedia.org/wiki/Endomembrane_systemhttp://en.wikipedia.org/wiki/Eukaryotehttp://en.wikipedia.org/wiki/Cell_(biology)http://en.wikipedia.org/wiki/Cell_nucleushttp://en.wikipedia.org/wiki/Nuclear_envelopehttp://en.wikipedia.org/wiki/RNAhttp://en.wikipedia.org/wiki/Ribosomeshttp://en.wikipedia.org/wiki/Proteinhttp://en.wikipedia.org/wiki/DNA_polymerasehttp://en.wikipedia.org/wiki/DNA_polymerasehttp://en.wikipedia.org/wiki/Laminhttp://en.wikipedia.org/wiki/Carbohydrateshttp://en.wikipedia.org/wiki/Carbohydrateshttp://en.wikipedia.org/wiki/Signaling_moleculehttp://en.wikipedia.org/wiki/Signaling_moleculehttp://en.wikipedia.org/wiki/Lipidshttp://en.wikipedia.org/wiki/Lipid_bilayerhttp://en.wikipedia.org/wiki/Eukaryotehttp://en.wikipedia.org/wiki/Cell_(biology)http://en.wikipedia.org/wiki/Cell_nucleushttp://en.wikipedia.org/wiki/DNAhttp://en.wikipedia.org/wiki/Cytosolhttp://en.wikipedia.org/wiki/Cytoplasmhttp://en.wikipedia.org/wiki/Nuclear_porehttp://en.wikipedia.org/wiki/Proteinhttp://en.wikipedia.org/wiki/RNAhttp://en.wikipedia.org/wiki/RNAhttp://en.wikipedia.org/wiki/Proteinhttp://en.wikipedia.org/wiki/Nuclear_porehttp://en.wikipedia.org/wiki/Cytoplasmhttp://en.wikipedia.org/wiki/Cytosolhttp://en.wikipedia.org/wiki/DNAhttp://en.wikipedia.org/wiki/Cell_nucleushttp://en.wikipedia.org/wiki/Cell_(biology)http://en.wikipedia.org/wiki/Eukaryotehttp://en.wikipedia.org/wiki/Lipid_bilayerhttp://en.wikipedia.org/wiki/Lipidshttp://en.wikipedia.org/wiki/Signaling_moleculehttp://en.wikipedia.org/wiki/Signaling_moleculehttp://en.wikipedia.org/wiki/Carbohydrateshttp://en.wikipedia.org/wiki/Carbohydrateshttp://en.wikipedia.org/wiki/Laminhttp://en.wikipedia.org/wiki/DNA_polymerasehttp://en.wikipedia.org/wiki/DNA_polymerasehttp://en.wikipedia.org/wiki/Proteinhttp://en.wikipedia.org/wiki/Ribosomeshttp://en.wikipedia.org/wiki/RNAhttp://en.wikipedia.org/wiki/Nuclear_envelopehttp://en.wikipedia.org/wiki/Cell_nucleushttp://en.wikipedia.org/wiki/Cell_(biology)http://en.wikipedia.org/wiki/Eukaryotehttp://en.wikipedia.org/wiki/Endomembrane_systemhttp://en.wikipedia.org/wiki/Nuclear_envelopehttp://en.wikipedia.org/wiki/Protein
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    PLANT CELL

    Plant cells like animal cells are eukaryotic, i.e. they contain membrane bound nuclei and cell

    organelles. A plant cell differs from an animal cell in having certain distinctive structures - cell wall,

    vacuoles, plasmodesmata and plastids. On the contrary, plant cells lack centrioles and intermediate

    filaments, which are present in animal cells. Despite these, plant and animal cells share several

    similarities in structure, parts and their roles.

    Plant cells are classified into three types, based on the structure and function, viz. parenchyma,

    collenchyma and sclerenchyma. The parenchyma cells are living, thin-walled and undergo repeated cell

    division for growth of the plant. They are mostly present in the leaf epidermis, stem pith, root and fruit

    pulp. Mature collenchyma cells are living, and provide stretchable support to the plant. Lastly,

    sclerenchyma cells (e.g. fiber cells) are hard, non-living and give mechanical support to plants. Now, let

    us see the different parts of a plant cell with their significant roles.

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    CELL PARTS AND ITS FUNCTIONS

    CELL WALL DESCRIPTION FUNCTION

    The cell wall is the tough,

    usually flexible but sometimes

    fairly rigid layer that surrounds

    some types ofcells. It is located

    outside the cell membrane. It

    comprises cellulose,

    hemicellulose, pectin and at

    other times, lignin. As expected,

    it remains connected with the

    cell walls of other cells.

    The prime functions of cell wall

    are protection, giving structural

    support and helping in the filter

    mechanism. A major function of

    the cell wall is to act as a pressure

    vessel, preventing over-expansion

    when water enters the cell

    CELL MEMBRANE Cell membrane, also called

    plasma membrane, is present

    inside the cell wall and

    surrounds the cytoplasm. the

    thin layer of protein and fat that

    surrounds the cell, but is inside

    the cell wall. The cell membrane

    is semipermeable, allowing

    some substances to pass into

    the cell and blocking others.

    It connects the intracellular

    components (organelles and

    cytoplasm) with the extracellular

    environment, and helps in

    protection and transportation.

    The cell membrane is permeable

    to specific substances only.

    http://en.wikipedia.org/wiki/Cell_(biology)http://en.wikipedia.org/wiki/Cell_membranehttp://en.wikipedia.org/wiki/Cell_membranehttp://en.wikipedia.org/wiki/Cell_(biology)
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    NUCLEAR MEMBRANE The nuclear membrane and the

    nuclear envelope mean one and

    same thing. As the name reveals,

    it is the outer covering of the

    nucleus.

    It separates the cytoplasmic

    contents from the nuclear

    contents. Nonetheless, minute

    pores (nuclear pores) are present

    for exchanging materials between

    the nucleus and cytoplasm.

    NUCLEUSNucleus is a specialized organelle,

    which contains the plant's

    hereditary material i.e. DNA

    (Deoxyribonucleic Acid). Inside

    the nucleus, a dense, spherical

    body called nucleolus is present.

    The nucleus contains structures,

    which regulates the cell cycle,

    growth, protein synthesis and

    reproductive function.

    The function of the nucleus is to

    maintain the integrity of these

    genes and to control the activities

    of the cell by regulating gene

    expression the nucleus is,

    therefore, the control center of

    the cell. The nucleus controls

    many of the functions of the cell

    (by controlling protein synthesis)

    and contains DNA (in

    chromosomes).

    VACUOLEA large, membrane-bound space

    within a plant cell that is filled

    with fluid. Most plant cells have a

    single vacuole that takes up much

    of the cell.

    They function as storage,

    excretory and secretory

    organelles. The membrane

    surrounding a vacuole is called

    tonoplast. A mature plant cell has

    a single vacuole at the near

    center of the cell (central

    vacuole), which contributes toabout 30-80 percent of the cell's

    volume.

    http://en.wikipedia.org/wiki/Gene_expressionhttp://en.wikipedia.org/wiki/Gene_expressionhttp://en.wikipedia.org/wiki/Gene_expressionhttp://en.wikipedia.org/wiki/Gene_expression
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    CYTOPLASM Cytoplasm is filled up by cytosol,

    which is a gelatinous and

    semitransparent fluid. All

    the organelles of the plant

    cell are present in this cytoplasm.

    This part of the plant cell is the

    site for cell division, glycolysis and

    many other cellular activities.

    Also, the cytoskeleton elements

    (microtubules and

    microfilaments) are present in the

    cytosol.

    PLASTID/CHLOROPLASTSChloroplasts are organelles found

    in plant cells and

    other eukaryotic organisms that

    conduct photosynthesis.

    Chloroplasts are green because

    they contain

    the pigment chlorophyll. The

    word chloroplastis derived from

    the Greek words chloros which

    means green, andplastis which

    means "the one who forms".

    Chloroplasts are members of a

    class of organelles known

    as plastids.

    Plastids are organelles

    responsible for photosynthetic

    activity, manufacturing and

    storage of chemical compounds in

    plants. Chloroplast is an

    important form of plastid

    containing chlorophyll pigment,

    which helps in harvesting light

    energy and converting it to

    chemical energy. Likewise,

    chromoplast and other plastids

    are present in a plant cell.

    MITOCHONDRIAMitochondrion is a membrane-

    enclosed organellefound in

    most eukaryotic cells.[1]

    These

    organelles range from 0.5 to

    1.0 micrometers (m) in

    diameter. Mitochondria are

    sometimes described as "cellular

    power plants" because they

    generate most of the cell's supply

    ofadenosine triphosphate (ATP),

    used as a source ofchemical

    energy.

    They are responsible for breaking

    down complex carbohydrate and

    sugar molecules to simpler forms,

    which the plants can use. Other

    than this, mitochondria are

    crucial for cell signaling, cycle,

    division, growth and death.

    http://www.buzzle.com/articles/plant-cell-organelles.htmlhttp://www.buzzle.com/articles/plant-cell-organelles.htmlhttp://en.wikipedia.org/wiki/Organellehttp://en.wikipedia.org/wiki/Plant_cellhttp://en.wikipedia.org/wiki/Eukaryotehttp://en.wikipedia.org/wiki/Photosynthesishttp://en.wikipedia.org/wiki/Pigmenthttp://en.wikipedia.org/wiki/Chlorophyllhttp://en.wikipedia.org/wiki/Plastidhttp://en.wikipedia.org/wiki/Biological_membranehttp://en.wikipedia.org/wiki/Organellehttp://en.wikipedia.org/wiki/Eukaryotehttp://en.wikipedia.org/wiki/Cell_(biology)http://en.wikipedia.org/wiki/Mitochondria#cite_note-mitosomes-0http://en.wikipedia.org/wiki/Mitochondria#cite_note-mitosomes-0http://en.wikipedia.org/wiki/Mitochondria#cite_note-mitosomes-0http://en.wikipedia.org/wiki/Micrometrehttp://en.wikipedia.org/wiki/Micrometrehttp://en.wikipedia.org/wiki/Micrometrehttp://en.wikipedia.org/wiki/Adenosine_triphosphatehttp://en.wikipedia.org/wiki/Chemical_energyhttp://en.wikipedia.org/wiki/Chemical_energyhttp://en.wikipedia.org/wiki/Chemical_energyhttp://en.wikipedia.org/wiki/Chemical_energyhttp://en.wikipedia.org/wiki/Adenosine_triphosphatehttp://en.wikipedia.org/wiki/Micrometrehttp://en.wikipedia.org/wiki/Mitochondria#cite_note-mitosomes-0http://en.wikipedia.org/wiki/Cell_(biology)http://en.wikipedia.org/wiki/Eukaryotehttp://en.wikipedia.org/wiki/Organellehttp://en.wikipedia.org/wiki/Biological_membranehttp://en.wikipedia.org/wiki/Plastidhttp://en.wikipedia.org/wiki/Chlorophyllhttp://en.wikipedia.org/wiki/Pigmenthttp://en.wikipedia.org/wiki/Photosynthesishttp://en.wikipedia.org/wiki/Eukaryotehttp://en.wikipedia.org/wiki/Plant_cellhttp://en.wikipedia.org/wiki/Organellehttp://www.buzzle.com/articles/plant-cell-organelles.htmlhttp://www.buzzle.com/articles/plant-cell-organelles.html
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    ENDOPLASMIC RETICULUMRough endoplasmic reticulum -

    (rough ER) a vast system of

    interconnected, membranous,

    infolded and convoluted sacks

    that are located in the cell's

    cytoplasm. Rough ER is covered

    with ribosomes that give it a

    rough appearance.

    Smooth endoplasmic reticulum -

    (smooth ER) a vast system of

    interconnected, membranous,

    infolded and convoluted tubes

    that are located in the cell's. The

    space within the ER is called the

    ER lumen.

    The endoplasmic reticulum (ER)

    organelle plays a major role in

    manufacturing and storage of

    chemical compounds, like

    glycogen and steroids. It is alsoinvolved in translation and

    transportation of protein. ER is

    also connected to the nuclear

    membrane, so as to make a

    channel between the cytoplasm

    and the nucleus.

    PLASMODESMATA Plasmodesmata are microscopic

    channels which traverse the cell

    walls of plant cells. They are

    formed when portions of

    the endoplasmic reticulum are

    trapped across the middle

    lamella as new cell wall is laid

    down between two newly divided

    plant cells and these eventuallybecome the cytoplasmic

    connections between cells

    (primary plasmodesmata).

    Plasmodesma (plural

    plasmodesmata) is a small

    opening, which connects plant

    cells with each other. Present

    only in some types of algal cells

    and plants cells, this connecting

    channel enables transport of

    materials and allows

    communication between the

    cells. In a single plant cell, about1,000-100,000 plasmodesmata

    are present.

    GOLGI APPARATUS Also called the golgi apparatus or

    golgi complex. A flattened,

    layered, sac-like organelle that

    looks like a stack of pancakes andis located near the nucleus.

    It is an organelle responsible for

    processing of macromolecules

    (like carbohydrates, proteins and

    fats) and packaging them intomembrane-bound vesicles for

    transportation purposes. Golgi

    bodies are present near to the

    nucleus of the plant cell.

    http://en.wikipedia.org/wiki/Endoplasmic_reticulumhttp://en.wikipedia.org/wiki/Middle_lamellahttp://en.wikipedia.org/wiki/Middle_lamellahttp://en.wikipedia.org/wiki/Middle_lamellahttp://en.wikipedia.org/wiki/Middle_lamellahttp://en.wikipedia.org/wiki/Endoplasmic_reticulum
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    RIBOSOMESTiny spherical bodies that help

    make proteins. Found in the

    cytoplasm or attached to the

    endo plasmic reticulum.

    Ribosomes are organelles, which

    are made up of 60% RNA

    (Ribonucleic Acid) and 40%

    protein, and play an important

    role in protein translation. It

    won't be wrong to say that the

    main site of protein synthesis is

    ribosome.

    The organelles serve as the

    protein production machinery for

    the cell and are consequently

    most abundant in cells that are

    active in protein synthesis, such as

    pancreas and brain cells.

    MICROBODIESMicrobodies are single,

    membrane-bound, globular

    shaped organelles, which are

    found in the cytoplasm. They

    range in size from 0.5-1

    micrometer, and contain

    degradative enzymes. Many kinds

    of microbodies are present in a

    plant cell, of which the two most

    common types are peroxisomes

    and glyoxysomes.

    Microbodies are specialized as

    containers for metabolic activity.

    MICROTUBULESMicrotubules are straight, hollow,

    tubular cylinders, which are major

    elements of the cytoskeleton.

    These rope-like polymers

    oftubulin can grow as long as 25

    micrometers and are highly

    dynamic. The outer diameter of

    microtubule is about 25nm.

    These plant cell structures are

    involved in synthesizing cell wall.

    Function wise, they are crucial for

    structural support, cell division

    and transport of vesicles.

    Microtubules in a plant cell are

    simpler, as compared to those of

    an animal cell. They are conveyer

    belts inside the cells. They move

    vesicles, granules, organelles like

    mitochondria, and chromosomes

    via special attachment proteins.

    http://en.wikipedia.org/wiki/Tubulinhttp://en.wikipedia.org/wiki/Nanometrehttp://en.wikipedia.org/wiki/Nanometrehttp://en.wikipedia.org/wiki/Tubulin
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    MICROFILAMENTS Microfilaments are thin, filament

    like structures found in the

    cytosol, which contain actin

    subunits. These along with the

    microtubules make up the

    cytoskeleton of plants cells.

    These linear polymers ofactin

    subunits are flexible and relatively

    strong, resisting buckling by

    multi-piconewton compressive

    forces and filament fracture by

    nanonewton tensile forces.

    Microfilaments are highly

    versatile, functioning in cell

    crawling, amoeboid movement,

    and changes in cell shape.

    The cell membrane

    The cell membrane, also

    called the plasma

    membrane or

    plasmalemma, is a

    semipermeable lipid

    bilayer common to all

    living cells. It contains a

    variety of biological

    molecules, primarily

    proteins and lipids, which

    are involved in a vast

    array of cellular

    processes. It also servesas the attachment point

    for both the intracellular

    cytoskeleton and, if

    present, the cell wall.

    http://en.wikipedia.org/wiki/Biopolymerhttp://en.wikipedia.org/wiki/Actinhttp://en.wikipedia.org/wiki/Amoeboidhttp://en.wikipedia.org/wiki/Amoeboidhttp://en.wikipedia.org/wiki/Actinhttp://en.wikipedia.org/wiki/Biopolymer
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    Parts and its functions:

    1. Glycoproteins- are proteins that contain oligosaccharide chains (glycans) covalently

    attached to polypeptide side-chains. The carbohydrate is attached to the protein ina cotranslational or posttranslational modification. Glycoproteins are often

    important integral membrane proteins, where they play a role in cellcell interactions.

    Glycoproteins also occur in the cytosol, but their functions and the pathways producing

    these modifications in this compartment are less well-understood.

    2. Glycolipids- are lipids with a carbohydrate attached. Their role is to provide energy and also

    serve as markers for cellular recognition.

    3. Globular protein-or spheroproteins are one of the two main protein classes,

    comprising "globe"-like proteins that are more or less soluble in aqueous solutions (where

    they form colloidal solutions). This characteristic distinguishes them from fibrous

    proteins (the other class), which are practically insoluble.

    The term globin can refer more specifically to proteins including the globin fold.

    4. Phospholipids- are a class oflipids that are a major component of all cell membranes as

    they can form lipid bilayers. The first phospholipid identified as such in biological tissues

    was lecithin, or phosphatidylcholine. The structure of the phospholipid molecule generally

    consists of hydrophobic tails and a hydrophilic head. It is usually found

    with cholesterol molecules which are found in-between the spaces of the phospholipid..

    5. Proteins within the membrane are key to the functioning of the overall membrane. These

    proteins mainly transport chemicals and information across the membrane. Every

    membrane has a varying degree of protein content. Proteins can be in the form of

    peripheral or integral.

    Type Description Examples

    Integral proteins

    or transmembrane proteins

    Span the membrane and have a

    hydrophilic cytosolic domain, which interacts with

    internal molecules, a hydrophobic membrane-spanning domain that anchors it within the cell

    membrane, and a hydrophilic extracellular domain

    that interacts with external molecules. The

    hydrophobic domain consists of one, multiple, or a

    combination of-helices and

    sheet protein motifs.

    Ion channels,proton

    pumps, G protein-

    coupled receptor

    http://en.wikipedia.org/wiki/Proteinhttp://en.wikipedia.org/wiki/Oligosaccharidehttp://en.wikipedia.org/wiki/Glycanshttp://en.wikipedia.org/wiki/Peptidehttp://en.wikipedia.org/wiki/Translation_(genetics)http://en.wikipedia.org/wiki/Posttranslational_modificationhttp://en.wikipedia.org/wiki/Integral_membrane_proteinshttp://en.wikipedia.org/wiki/Cytosolhttp://en.wikipedia.org/wiki/Lipidshttp://en.wikipedia.org/wiki/Carbohydratehttp://en.wikipedia.org/wiki/Energyhttp://en.wikipedia.org/wiki/Genetic_markerhttp://en.wikipedia.org/wiki/Cell_(biology)http://en.wikipedia.org/wiki/Proteinhttp://en.wikipedia.org/wiki/Spherehttp://en.wikipedia.org/wiki/Aqueous_solutionhttp://en.wikipedia.org/wiki/Colloidalhttp://en.wikipedia.org/wiki/Fibrous_proteinhttp://en.wikipedia.org/wiki/Fibrous_proteinhttp://en.wikipedia.org/wiki/Globinhttp://en.wikipedia.org/wiki/Globin_foldhttp://en.wikipedia.org/wiki/Lipidshttp://en.wikipedia.org/wiki/Cell_membranehttp://en.wikipedia.org/wiki/Lipid_bilayerhttp://en.wikipedia.org/wiki/Lecithinhttp://en.wikipedia.org/wiki/Phosphatidylcholinehttp://en.wikipedia.org/wiki/Cholesterolhttp://en.wikipedia.org/wiki/Integral_proteinhttp://en.wikipedia.org/wiki/Cytosolhttp://en.wikipedia.org/wiki/Protein_domainshttp://en.wikipedia.org/wiki/Alpha_helixhttp://en.wikipedia.org/wiki/Alpha_helixhttp://en.wikipedia.org/wiki/Alpha_helixhttp://en.wikipedia.org/wiki/Beta_sheethttp://en.wikipedia.org/wiki/Beta_sheethttp://en.wikipedia.org/wiki/Beta_sheethttp://en.wikipedia.org/wiki/Structural_motifhttp://en.wikipedia.org/wiki/Proton_pumphttp://en.wikipedia.org/wiki/Proton_pumphttp://en.wikipedia.org/wiki/G_protein-coupled_receptorhttp://en.wikipedia.org/wiki/G_protein-coupled_receptorhttp://en.wikipedia.org/wiki/G_protein-coupled_receptorhttp://en.wikipedia.org/wiki/G_protein-coupled_receptorhttp://en.wikipedia.org/wiki/Proton_pumphttp://en.wikipedia.org/wiki/Proton_pumphttp://en.wikipedia.org/wiki/Structural_motifhttp://en.wikipedia.org/wiki/Beta_sheethttp://en.wikipedia.org/wiki/Beta_sheethttp://en.wikipedia.org/wiki/Alpha_helixhttp://en.wikipedia.org/wiki/Protein_domainshttp://en.wikipedia.org/wiki/Cytosolhttp://en.wikipedia.org/wiki/Integral_proteinhttp://en.wikipedia.org/wiki/Cholesterolhttp://en.wikipedia.org/wiki/Phosphatidylcholinehttp://en.wikipedia.org/wiki/Lecithinhttp://en.wikipedia.org/wiki/Lipid_bilayerhttp://en.wikipedia.org/wiki/Cell_membranehttp://en.wikipedia.org/wiki/Lipidshttp://en.wikipedia.org/wiki/Globin_foldhttp://en.wikipedia.org/wiki/Globinhttp://en.wikipedia.org/wiki/Fibrous_proteinhttp://en.wikipedia.org/wiki/Fibrous_proteinhttp://en.wikipedia.org/wiki/Colloidalhttp://en.wikipedia.org/wiki/Aqueous_solutionhttp://en.wikipedia.org/wiki/Spherehttp://en.wikipedia.org/wiki/Proteinhttp://en.wikipedia.org/wiki/Cell_(biology)http://en.wikipedia.org/wiki/Genetic_markerhttp://en.wikipedia.org/wiki/Energyhttp://en.wikipedia.org/wiki/Carbohydratehttp://en.wikipedia.org/wiki/Lipidshttp://en.wikipedia.org/wiki/Cytosolhttp://en.wikipedia.org/wiki/Integral_membrane_proteinshttp://en.wikipedia.org/wiki/Posttranslational_modificationhttp://en.wikipedia.org/wiki/Translation_(genetics)http://en.wikipedia.org/wiki/Peptidehttp://en.wikipedia.org/wiki/Glycanshttp://en.wikipedia.org/wiki/Oligosaccharidehttp://en.wikipedia.org/wiki/Protein
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    Lipid anchored proteins

    Covalently bound to single or multiple lipid

    molecules; hydrophobically insert into the cell

    membrane and anchor the protein. The protein

    itself is not in contact with the membrane.

    G proteins

    Peripheral proteins Attached to integral membrane proteins, or

    associated with peripheral regions of the lipid

    bilayer. These proteins tend to have only

    temporary interactions with biological membranes,

    and, once reacted the molecule, dissociates to

    carry on its work in the cytoplasm.

    Some enzymes,some

    hormones

    EUKARYOTIC AND PROKARYOTIC CELL

    EUKARYOTICEu =true, karyon =nucleus

    PROKARYOTICPro =before, karyon =nucleus

    SIMILARITIES Both have DNA as their genetic material (its DNA thattells cells what kind of cells they should be).

    Both are covered by a cell membrane.

    Both contain RNA.

    http://en.wikipedia.org/wiki/Lipid_anchored_proteinhttp://en.wikipedia.org/wiki/G_proteinhttp://en.wikipedia.org/wiki/Peripheral_proteinhttp://en.wikipedia.org/wiki/Peripheral_protein#Enzymeshttp://en.wikipedia.org/wiki/Peripheral_protein#Polypeptide_ligands_.28hormones.2C_inhibitors.2C_toxins.2C_antimicrobial_peptides.29http://en.wikipedia.org/wiki/Peripheral_protein#Polypeptide_ligands_.28hormones.2C_inhibitors.2C_toxins.2C_antimicrobial_peptides.29http://en.wikipedia.org/wiki/Peripheral_protein#Polypeptide_ligands_.28hormones.2C_inhibitors.2C_toxins.2C_antimicrobial_peptides.29http://en.wikipedia.org/wiki/Peripheral_protein#Polypeptide_ligands_.28hormones.2C_inhibitors.2C_toxins.2C_antimicrobial_peptides.29http://en.wikipedia.org/wiki/Peripheral_protein#Enzymeshttp://en.wikipedia.org/wiki/Peripheral_proteinhttp://en.wikipedia.org/wiki/G_proteinhttp://en.wikipedia.org/wiki/Lipid_anchored_protein
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    Both are made from the same basic chemicals:

    carbohydrates, proteins, nucleic acid, minerals, fats and

    vitamins.

    Both have ribosomes (the structures on which proteins

    are made).

    Both regulate the flow of the nutrients and wastes that

    enter and leave them.

    Both have similar basic metabolism (life processes) like

    photosynthesis and reproduction.

    Both require a supply of energy.

    Both are highly regulated by elaborate sensing systems

    ("chemical noses) that make them aware of the reactionswithin them and the environment around them.

    DIFFERENCES

    Eukaryotic cells have a true

    nucleus, bound by a double

    membrane.

    Eukaryotic DNA is linear

    Eukaryotic DNA is complexed with

    proteins called "histones," and is

    organized into chromosomes

    Prokaryotic cells have no

    nucleus.

    (Prokaryotic cell has no

    nucleus because its much

    smaller size means that all

    materials within the cell are

    relatively close together.)

    Prokaryotic DNA is circular (it

    has no ends).

    Prokaryotic DNA is "naked,"meaning that it has no

    histones associated with it,

    and it is not formed into

    chromosomes.

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    The ribosomes of the eukaryotic

    cells are larger and more complex.

    The cytoplasm of eukaryotic cells

    is filled with a large, complex

    collection of organelles, many of

    them enclosed in their own

    membranes.

    Eukaryotic cells are often

    multicellular.

    Eukaryotic cells reproduce/divide

    by mitosis/meiosis

    Larger cells (>10 m)

    Always has a cytoskeleton

    Reproduction is asexual or sexual

    Common metabolic pathways

    The ribosomes of prokaryotic

    cells are small and clear.

    The prokaryotic cell contains

    no membrane-bound

    organelles which are

    independent of the plasma

    membrane.

    Prokaryotic cells are always

    unicellular

    Prokaryotic cells

    reproduce/divide by binary

    fission

    Small cells (

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    Biological function of a cell

    1. Movement or Motility- is a biological term which refers to the ability to move spontaneously

    and actively, consuming energy in the process. All animals are motile but the term applies to

    single-celled and simple multicellular organisms, as well as to some mechanisms of fluid flow in

    multicellular organs, in addition to animal locomotion. Motile marine animals are commonly

    called free-swimming.

    * Cell motility is one of the crowning achievements of evolution. Primitive cells were probably

    immobile, carried by currents in the primordial milieu. With the evolution of multicellular

    organisms, primitive organs were formed by migrations of single cells and groups of cells from

    distant parts of the embryo. In adult organisms, movements of single cells in search of foreign

    organisms are integral to the hosts defenses against infection; on the other hand, uncontrolled

    cell migration is an ominous sign of a cancerous cell.

    2. Sensitivity or Irritability- The ability of the cell to receive and respond to a stimulus. Muscle cells

    are irritable and respond to stimuli. Muscle twitch is defined as contraction and relaxation in the

    muscle cell. The stimulus needs to be above a certain threshold for the muscle fibres to react.

    The more the stimulus, the greater the strength of the contraction.

    3. Growth and metabolism- Between successive cell divisions, cells grow through the functioning

    of cellular metabolism. Cell metabolism is the process by which individual cells process nutrient

    molecules. Metabolism has two distinct divisions: catabolism, in which the cell breaks down

    complex molecules to produce energy and reducing power, and anabolism, in which the cell

    uses energy and reducing power to construct complex molecules and perform other biological

    functions. Complex sugars consumed by the organism can be broken down into a less chemically

    complex sugar molecule called glucose. Once inside the cell, glucose is broken down to make

    adenosine triphosphate (ATP), a form of energy, through two different pathways.

    *The first pathway, glycolysis, requires no oxygen and is referred to as anaerobic metabolism.

    Each reaction is designed to produce some hydrogen ions that can then be used to make energy

    packets (ATP). In prokaryotes, glycolysis is the only method used for converting energy.

    *The second pathway, called the Krebs cycle, or citric acid cycle, occurs inside the mitochondria

    and can generate enough ATP to run all the cell functions.

    4. Mutations- are changes in a genomic sequence: the DNA sequence of a cell's genome or the

    DNA or RNA sequence of a virus. They can be defined as sudden and spontaneous changes in

    the cell. Mutations are caused by radiation, viruses, transposons and mutagenic chemicals, as

    well as errors that occur during meiosis or DNA replication. They can also be induced by the

    http://en.wikipedia.org/wiki/Biologyhttp://en.wikipedia.org/wiki/Animalhttp://en.wikipedia.org/wiki/Animal_locomotionhttp://en.wikipedia.org/wiki/Marine_animalhttp://www.biology-online.org/dictionary/Cellhttp://www.biology-online.org/dictionary/Stimulushttp://en.wikipedia.org/wiki/Catabolismhttp://en.wikipedia.org/wiki/Anabolismhttp://en.wikipedia.org/wiki/Glucosehttp://en.wikipedia.org/wiki/Adenosine_triphosphatehttp://en.wikipedia.org/wiki/Glycolysishttp://en.wikipedia.org/wiki/Fermentation_(biochemistry)http://en.wikipedia.org/wiki/Citric_acid_cyclehttp://en.wikipedia.org/wiki/Genomehttp://en.wikipedia.org/wiki/DNAhttp://en.wikipedia.org/wiki/Genomehttp://en.wikipedia.org/wiki/RNAhttp://en.wikipedia.org/wiki/Radioactive_decayhttp://en.wikipedia.org/wiki/Virushttp://en.wikipedia.org/wiki/Transposonhttp://en.wikipedia.org/wiki/Mutagenhttp://en.wikipedia.org/wiki/DNA_errorhttp://en.wikipedia.org/wiki/Meiosishttp://en.wikipedia.org/wiki/DNA_replicationhttp://en.wikipedia.org/wiki/DNA_replicationhttp://en.wikipedia.org/wiki/Meiosishttp://en.wikipedia.org/wiki/DNA_errorhttp://en.wikipedia.org/wiki/Mutagenhttp://en.wikipedia.org/wiki/Transposonhttp://en.wikipedia.org/wiki/Virushttp://en.wikipedia.org/wiki/Radioactive_decayhttp://en.wikipedia.org/wiki/RNAhttp://en.wikipedia.org/wiki/Genomehttp://en.wikipedia.org/wiki/DNAhttp://en.wikipedia.org/wiki/Genomehttp://en.wikipedia.org/wiki/Citric_acid_cyclehttp://en.wikipedia.org/wiki/Fermentation_(biochemistry)http://en.wikipedia.org/wiki/Glycolysishttp://en.wikipedia.org/wiki/Adenosine_triphosphatehttp://en.wikipedia.org/wiki/Glucosehttp://en.wikipedia.org/wiki/Anabolismhttp://en.wikipedia.org/wiki/Catabolismhttp://www.biology-online.org/dictionary/Stimulushttp://www.biology-online.org/dictionary/Cellhttp://en.wikipedia.org/wiki/Marine_animalhttp://en.wikipedia.org/wiki/Animal_locomotionhttp://en.wikipedia.org/wiki/Animalhttp://en.wikipedia.org/wiki/Biology
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    organism itself, by cellular processes such as hypermutation. A mutation is passed to the

    offspring stably, unless it is a dynamic mutation.

    5. Respiration-is the set of the metabolic reactions and processes that take place in

    the cells oforganisms to convert biochemical energy from nutrients into adenosinetriphosphate (ATP), and then release waste products. The reactions involved in respiration

    are catabolic reactions that involve the redox reaction (oxidation of one molecule and

    the reduction of another). Respiration is one of the key ways a cell gains useful energy to fuel

    cellular reformations.

    6. Excretion- is the process in which a cell gets rid of the wastes and toxins that could be damaging

    it, by its cell membrane. In single-celled organisms, waste products are discharged directly

    through the surface of the cell. Multicellular organisms utilize more complex excretory methods.

    Higher plants eliminate gases through the stomata, or pores, on the surface of leaves. Animals

    have special excretory organs.

    7. Secretion- Many cells secrete proteins into their surrounding extracellular fluid. Some cells, for

    example, secrete regulatory molecules such as hormones and neurotransmitters. Others release

    digestive enzymes, antibodies, or mucus. And throughout the body, cells such

    as fibroblasts secrete collagen and other structural proteins to provide strength and hold the

    body together.

    8. Absorption- is the uptake of materials from a cells' external environment. The process ofabsorbing or assimilating substances into cells or across the tissues and organs through

    diffusion or osmosis, as in absorption of nutrients by the digestive system, or absorption of

    drugs into the bloodstream.

    9. Energy- Life is an energy intensive process. It takes energy to operate muscles, extract wastes,

    make new cells, heal wounds, even to think. Its in an organisms cells where all this energy is

    spent. In some cells, as much as half of a cells energy output is used to transfer molecules

    across the cell membrane, a process called active transport. Cell movements require energy and

    thousands of energy-hungry chemical reactions go on in every living cell, every second, every

    day. The kind of energy cells use is chemical bond energy, the shared electrons that holds atoms

    together in molecules.

    10. Transport- Some cells are responsible for transporting materials from one place in the body to

    another. In humans, for instance, cells lining the small intestine transport the molecular

    products of digestion from the inside of the gut to the bloodstream. Glucose, for instance, which

    http://en.wikipedia.org/wiki/Cellular_processeshttp://en.wikipedia.org/wiki/Somatic_hypermutationhttp://en.wikipedia.org/wiki/Dynamic_mutationhttp://en.wikipedia.org/wiki/Metabolismhttp://en.wikipedia.org/wiki/Cell_(biology)http://en.wikipedia.org/wiki/Organismhttp://en.wikipedia.org/wiki/Energy#Energy_and_lifehttp://en.wikipedia.org/wiki/Adenosine_triphosphatehttp://en.wikipedia.org/wiki/Adenosine_triphosphatehttp://en.wikipedia.org/wiki/Catabolismhttp://en.wikipedia.org/wiki/Redoxhttp://en.wikipedia.org/wiki/Redoxhttp://en.wikipedia.org/wiki/Redoxhttp://en.wikipedia.org/wiki/Microorganismhttp://en.wikipedia.org/wiki/Multicellular_organismhttp://en.wikipedia.org/wiki/Planthttp://en.wikipedia.org/wiki/Stomatahttp://www.biology-online.org/dictionary/Cellshttp://www.biology-online.org/dictionary/Diffusionhttp://www.biology-online.org/dictionary/Osmosishttp://www.biology-online.org/dictionary/Osmosishttp://www.biology-online.org/dictionary/Diffusionhttp://www.biology-online.org/dictionary/Cellshttp://en.wikipedia.org/wiki/Stomatahttp://en.wikipedia.org/wiki/Planthttp://en.wikipedia.org/wiki/Multicellular_organismhttp://en.wikipedia.org/wiki/Microorganismhttp://en.wikipedia.org/wiki/Redoxhttp://en.wikipedia.org/wiki/Redoxhttp://en.wikipedia.org/wiki/Redoxhttp://en.wikipedia.org/wiki/Catabolismhttp://en.wikipedia.org/wiki/Adenosine_triphosphatehttp://en.wikipedia.org/wiki/Adenosine_triphosphatehttp://en.wikipedia.org/wiki/Energy#Energy_and_lifehttp://en.wikipedia.org/wiki/Organismhttp://en.wikipedia.org/wiki/Cell_(biology)http://en.wikipedia.org/wiki/Metabolismhttp://en.wikipedia.org/wiki/Dynamic_mutationhttp://en.wikipedia.org/wiki/Somatic_hypermutationhttp://en.wikipedia.org/wiki/Cellular_processes
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    is also called blood sugar, is transported by specialized cells that move glucose molecules out of

    the intestine together with sodium ions

    11. Storage- Some cells specialize in storage. Adipose cells, for instance, serve the purpose of

    storing large quantities of triacylglyceride, or fat, explain Drs. Campbell and Farrell. While mostbody cells can burn sugar, protein or fat for energy, fat provides far more energy per gram of

    weight, so its most efficient as a stored fuel. While adipose cells dont engage in many other

    functionstheyre not particularly active with regard to anything else the body doesthey do

    serve the valuable role of providing for the rest of the bodys energy needs when food is scarce.

    12. Communication- In order to keep a multicellular organism running efficiently, there must be

    cell-to-cell communication. While neighboring cells can communicate with one another without

    significant difficulty, things become a bit more complicated when, for instance, a gland in the

    brain needs to send a message to the gonads. Specialized cells, therefore, secrete

    communication molecules, called hormones, into the blood stream. The anterior pituitary gland

    in the brain, for instance, secretes a hormone that travels throughout the body, but only cells on

    the gonads respond to the hormone, notes Lauralee Sherwood in her text Human Physiology.

    In women, the gonadsovaries, in this caseripen an egg in preparation for ovulation in

    response to the pituitary hormone. In men, the testes produce sperm. Neurons are also

    communication cells. Instead of sending chemical messages via the bloodstream, however, they

    communicate directly with one another and with neighboring cells by using electrical impulses.

    13. Reproduction- organisms must produce new off-springs to replace the dying ones in the

    population. This is one of the most important life process. A species has to carry forward itsprogeny or else it would become extinct.

    Refences:

    www.wikipedia.org (accesed November, 2011)

    http://www.cod.edu/people/faculty/fancher/prokeuk.htm

    http://www.biologymad.com/resources/AS%20

    Cells.pdf

    http://www.enchantedlearning.com/subjects/animals/cell/

    http://jgimp.tripod.com/cells.html

    http://www.wikipedia.org/http://www.cod.edu/people/faculty/fancher/prokeuk.htmhttp://www.cod.edu/people/faculty/fancher/prokeuk.htmhttp://www.biologymad.com/resources/AS%20Cells.pdfhttp://www.biologymad.com/resources/AS%20Cells.pdfhttp://www.enchantedlearning.com/subjects/animals/cell/http://www.enchantedlearning.com/subjects/animals/cell/http://jgimp.tripod.com/cells.htmlhttp://jgimp.tripod.com/cells.htmlhttp://www.enchantedlearning.com/subjects/animals/cell/http://www.enchantedlearning.com/subjects/animals/cell/http://www.biologymad.com/resources/AS%20Cells.pdfhttp://www.biologymad.com/resources/AS%20Cells.pdfhttp://www.cod.edu/people/faculty/fancher/prokeuk.htmhttp://www.cod.edu/people/faculty/fancher/prokeuk.htmhttp://www.wikipedia.org/
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    Bicol University

    COLLEGE OF SCIENCE

    Chemistry Department

    Legazpi city

    ACTIVITY no. 1

    Inna Coleen A. Yanzon

    BS NURSING- 1B