Chap 2 cell structure and cell organisation

Chapter 2 : Cell

Structure and Cell

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Draw three typical cheek cells (x40) magnification

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Draw three typical cheek cells (x100) magnification

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Draw three typical onion cells (x40) magnification

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Draw three typical onion cells (x100) magnification

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Animal cell organelles

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Plant cell organelles

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Structure & Function of Cellular Components

Structure

Characteristics Function

Cell wall Composes of ________, a tough and fibrous ___________._________ membrane.

Gives __________ to plant cells.Protects the cell plant from _________ due to excessive intake of __________.

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Structure

Characteristics Function

Cell membrane

Made up of __________ and __________.A _____________ membrane.

To separate the contents of the cell from the _______ __________.___________ the movement of ________ into and out of the cytoplasm.

Nucleus Enclosed by a ________ membrane.Consists __________ & spherical structure called a ____________.

Controls the _________ of the cell.Carries __________ information.

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Structure Characteristics FunctionCytoplasm Region between

the _________ and ______ ____________.Consists of jelly-like __________.

Medium for __________ processes in the cell.Provide substances obtained from the external environment to the ____________.

Mitochondrion A __________-shaped organelle.

Involves in cell __________.Energy is stored in the form of ________.

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Structure

Characteristics Function

Rough E.R.

Has ________ attached to its surface.

Transports _________ synthesised by the ___________.

Smooth E.R.

Does not have ________ attached to its surface.

Site for _______ synthesis & __________ of poisons.

E.R. = Endoplasmic reticulumArnieAdnan

Structure

Characteristics Function

Ribosomes

Compact ___________ organelles.Either attached to the _________ _________ or suspended freely in the __________.

To synthesise __________.

Golgi apparatus

Consists of a stack of __________ _______________ sacs.

Centre for __________, ________ & _________ of carbohydrates, _________ & glycoproteins.

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Structure & Function of Cellular Components

Structure

Characteristics Function

Cell wall Composes of ________, a tough and fibrous ___________._________ membrane.

Gives __________ to plant cells.Protects the cell plant from _________ due to excessive intake of __________.

cellulosecarbohyd

ratesFully

support

burstingwater

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Structure

Characteristics Function

Cell membrane

Made up of __________ and __________.A _____________ membrane.

To separate the contents of the cell from the _______ __________.___________ the movement of ________ into and out of the cytoplasm.

Nucleus Enclosed by a ________ membrane.Consists __________ & spherical structure called a ____________.

Controls the _________ of the cell.Carries __________ information.

proteinslipids

semi-permeable

external environmentRegulates substa

ncesbilayer

chromosomesnucleolus

activitiesgenetic

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Structure Characteristics FunctionCytoplasm Region between

the _________ and ______ ____________.Consists of jelly-like __________.

Medium for __________ processes in the cell.Provide substances obtained from the external environment to the ____________.

Mitochondrion A __________-shaped organelle.

Involves in cell __________.Energy is stored in the form of ________.

nucleus plasmamembranemedium

biochemical

organellescylindric

al respiration

ATPArnieAdnan

Structure

Characteristics Function

Rough E.R.

Has ________ attached to its surface.

Transports _________ synthesised by the ___________.

Smooth E.R.

Does not have ________ attached to its surface.

Site for _______ synthesis & __________ of poisons.

E.R. = Endoplasmic reticulum

ribosomes

proteinsribosomes

ribosomes

lipiddetoxification

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Structure

Characteristics Function

Ribosomes

Compact ___________ organelles.Either attached to the _________ _________ or suspended freely in the __________.

To synthesise __________.

Golgi apparatus

Consists of a stack of __________ _______________ sacs.

Centre for __________, ________ & _________ of carbohydrates, _________ & glycoproteins.

spherical

endoplasmic

reticulumcytoplas

m

proteins

flattenedmembrane-bound

processingpackagi

ngtransportingproteins

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A comparison between a plant cell an animal cell.

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The similarities in animal and plant cells

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The differences between animal cells and plant cells

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All cells have the same basic structure but the density of some of the organelles may differ according to the function of the cell.For example, a sperm cell has a lot of mitochondria to help it swim while the salivary glands have a lot of golgi apparatus to produce enzymes.

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Types of cells Function

Organelle found

abundantly in the cell

Sperm cells

To ________ _______.

M____________

Muscle cells

To enable __________.

______________

Meristematic cells

To carry out __________ ________ _________.

M_____________

Relationship between the Density of Certain Organelles with the Functions of Specific

Cells

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Types of cells Function

Organelle found

abundantly in the cell

Mesophyll cells

To carry out ___________.

C___________

Pancreatic cells

To synthesise & ______ enzymes & __________.

E________ _______,_______ a________

Relationship between the Density of Certain Organelles with the Functions of Specific

Cells

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Types of cells Function

Organelle found

abundantly in the cell

Sperm cells

To ________ _______.

M____________

Muscle cells

To enable __________.

______________

Meristematic cells

To carry out __________ ________ _________.

M_____________

Relationship between the Density of Certain Organelles with the Functions of Specific

Cells

fertilise ovum

itochondrion

movementsMitochondrion

mitotic cell division

itochondrion

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Types of cells Function

Organelle found

abundantly in the cell

Mesophyll cells

To carry out ___________.

C___________

Pancreatic cells

To synthesise & ______ enzymes & __________.

E________ _______,_______ ________

Relationship between the Density of Certain Organelles with the Functions of Specific

Cells

photosynthesis

hloroplasts

secretehormones

ndoplasmic reticulumGolgi apparatus

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Life Processes Amoeba sp. Paramecium

HabitatStructureFeeding (nutrition)LocomotionRespirationOsmoregulationExcretionGrowthSensitivityReproduction

Living Processes of Unicellular Organisms

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Life Processes Amoeba sp. Paramecium

Habitat Found in fresh water, marine environment & soil water.

Lives in slow-flowing fresh water, ponds, lakes or stagnant water containing decaying organic matter.

Structure •Irregular in shape•Single cell surrounded by a plasma membrane•Moves & feeds using pseudopodia

•Outer surface is covered with cilia.•Cilia are involved in feeding & locomotion.

Living Processes of Unicellular Organisms

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Life Process

esAmoeba sp. Paramecium

Feeding (nutrition)

•Amoeba engulfs food by phagocytosis using pseudopodia.•Two pseudopodia extend out & enclose the food particles.•The food particles (packaged in vacuole) are digested by lysozimes.

•Beating of the cilia along the oral groove sweeps water & suspended foods into cytostome.•Food vacuole is formed, foods are digested by hydrolytic enzyme.•Digested foods then diffuse into the cytoplasm.•Undigested food is digested via the anal pore.

Living Processes of Unicellular Organisms

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Life Processes Amoeba sp. Paramecium

Locomotion •It moves by cytoplasmic projection – by extending its pseudopodia•Cytoplasm flows into the projected pseudopodia & anchoring the tips to the ground.

•Using the rhythmic beating of the cilia.•Enables the paramecium to move forward while rotating & spiraling along its axis.

Living Processes of Unicellular Organisms

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Life Processes Amoeba sp. Paramecium

Respiration Gases exchange (takes ins O2 & releases CO2) by diffusion across the body surface//plasma membrane.

Osmoregulation

•Excess water diffuses into the contractile vacuole, causing it to enlarge & fuses with cell membrane. •The excess water & waste materials are expelled to the surrounding water.

•Excess water & waste products are collected by the contractile vacuole.•Its then contract & the contents are expelled to the surrounding water.

Living Processes of Unicellular Organisms

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Life Processes Amoeba sp. Paramecium

Excretion •Waste products (CO2 & urea) are expelled by diffusion.•Its contractile vacuole contracts to control osmotic pressure (osmoregulation) by expelling excess water & their contents.

Growth Grows by synthesising new cytoplasm.

Sensitivity

•Moves away from unfavourable stimuli; acids & bright light.•Moves towards favourable stimuli.

•Sensitive to chemicals, O2, CO2, temperature & changes in light intensity

Living Processes of Unicellular Organisms

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Life Processes Amoeba sp. Paramecium

Reproduction

Reproduces asexually by binary fission and by forming spores.

Reproduces asexually by binary fission and also sexually by conjugation.

Living Processes of Unicellular Organisms

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HOMEWORK1. Discuss the following

a) Living processes in unicellular organisms. [10 marks]

b) Cell organization in multicellular organisms. [10 marks]

2. Explain briefly the mechanism involves in maintaining internal environment. [4 marks]

3. By giving examples, explain how various systems in the human body interact with one another to maintain a stable internal environment. [6 marks]

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1 (a)• Unicellular organisms are organisms

with a single cell.• Although they have only one cell,

they are able to perform all vital functions and living processes such as feeding, respiration, locomotion, excretion, growth and reproduction. For example, Paramecium

• Paramecium uses its cilia to sweep food particles into the cell mouth.

• It moves by moving its cilia. The rhythmic and coordinated beating of the cilia propels the Paramecium forward.

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• Gaseous exchange takes place by diffusion through the entire plasma membrane of the Paramecium.

• It uses its contractile vacuole to control water balance (osmoregulation) in the cell.

• Excretory wastes such as carbon dioxide and nitrogenous compounds diffuse from the cell to the surroundings.

• It grows by synthesising new cytoplasm.

• Paramecium reproduces by binary fission when the condition is favourable and by conjugation when the condition is unfavourable.

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1 (b)• Multicellular organisms are

organisms that consist of more than one cell. These organisms need specialised cells to carry out different functions in their bodies.

• Cell organisation that makes up a multicellular organisms are as follows:Cells tissues organs systems multi- cellular organism

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• A system consists of several organs that work together to perform a common function.

• An organ consists of several types of tissues working together to perform a particular function.

• Examples of systems are digestive system, skeletal system, reproductive system and circulatory system.

• There are four types of tissues in an animal. They are epithelial tissues, muscle tissues, nerve tissues and connective tissues.

• Some epithelial tissues undergo changes to become glands.

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• Muscle tissues are composed of muscle fibres. There are three types of muscle tissues; cardiac muscles, smooth muscles and skeletal muscles.

• Cardiac muscles can be found in the wall of the heart. Smooth muscles can be found in the intestine, blood vessels and urinary tracts. Skeletal muscles can be found attached to the bones.

• Nerves tissues are composed of neurons. The function of nerve tissues is to detect stimuli and transmit impulses.

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• There are various types of connective tissues. Loose connective tissues bind epithelia to underlying tissues and hold the organ in its place. Examples of dense fibrous connective tissues are the tendons and ligaments.

• Cartilage is a strong and flexible connective tissue that provides support to the nose and ears.

• Bones consist of cells embedded in a matrix of collagen and are hardened by mineral deposits that give protection to the internal organs.

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• Blood is a connective tissue which function in transport and body defence.

• Adipose tissues consist of tightly packed cells that stores fat.

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