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Cell LectureCell Lecture
By Mrs. SchmitBy Mrs. Schmit
What are Cells?What are Cells?
The basic unit of life. The basic unit of life. All living things are composed of cellsAll living things are composed of cells
ProkaryotesProkaryotes
Very simpleVery simple
no “true nucleus”no “true nucleus”
Almost everything functions in the cytoplasmAlmost everything functions in the cytoplasm
Still make proteins and have DNAStill make proteins and have DNAUsually smaller more primitiveUsually smaller more primitiveOften BacteriaOften Bacteria
EukaryotesEukaryotes
have a nucleus have a nucleus
Larger, more advancedLarger, more advanced
Can be unicellular like bacteria, Can be unicellular like bacteria, protists or multicellular like animals, protists or multicellular like animals, plantsplants
The Cell TheoryThe Cell Theory
All living things are made of cells.All living things are made of cells.
Cells come from other cells (Cell Division).Cells come from other cells (Cell Division).
Cells are the smallest working units of living Cells are the smallest working units of living things. things.
What allowed us to see What allowed us to see cells?cells?
The Microscope invented by Anton Von The Microscope invented by Anton Von LeeuwenhoekLeeuwenhoek
Name cell came from Robert Hooke in Name cell came from Robert Hooke in 16651665
Levels of OrganizationLevels of Organizationcellcell
tissuetissue
organorgan
Organ systemOrgan system
OrganismOrganism
PopulationsPopulations
CommunitiesCommunities
EcosystemEcosystem
BiosphereBiosphere
Cell DiversityCell Diversity Not all cells are alike. They vary in size, shape Not all cells are alike. They vary in size, shape
and internal organization.and internal organization. Your body contains over 300 different cell typesYour body contains over 300 different cell types
Internal OrganizationInternal Organization
Cells contain a variety of internal Cells contain a variety of internal structures called organelles (organs of structures called organelles (organs of the cell).the cell).
Organelles are cell organs that perform a Organelles are cell organs that perform a specific functionspecific function
Many of these organelles contain their Many of these organelles contain their own membranesown membranes
Parts and Functions of Parts and Functions of CellCell
Cell parts are often referred to as Cell parts are often referred to as
“ “ORGANELLES”ORGANELLES”
This is the Organ of a CellThis is the Organ of a Cell
See it in the word above?See it in the word above?
CytoplasmCytoplasm
Cytoplasm
CytoplasmCytoplasm
The “juice” of the cell.The “juice” of the cell. The “right” The “right”
environment for the environment for the chemical reactions of chemical reactions of the cell.the cell.
Cell Membrane
Or phospholipid bilayerOr phospholipid bilayer
The barrier between the cell The barrier between the cell and the environment.and the environment.
Controls what gets in and Controls what gets in and out of a cell.out of a cell.
Building different Building different membranesmembranes is one way is one way different cell types are different cell types are made.made.
Plant CellPlant Cell
Cell Wall
Plant CellPlant Cell
Key Feature?
Tough, rigid
CELL WALL
Purpose is to keep organisms from penetrating the wall and getting inside the cell itself
Cell WallCell Wall
Made of cellulose.Made of cellulose. Serves to give a firm Serves to give a firm
structure to plantsstructure to plants
Can’t poop? Eat Can’t poop? Eat more fiber (cellulose)more fiber (cellulose)
Nuclear MembraneNuclear Membrane
Membrane around Membrane around nucleus. nucleus.
Carefully controls Carefully controls what gets in and out.what gets in and out.
Protects DNA!Protects DNA!
NucleusNucleus
Nucleus
NucleusNucleus
Membrane Bound*Membrane Bound* Contains DNA (the Contains DNA (the
genetic instructions genetic instructions that make you… that make you… you). you).
Endoplasmic Reticulum Endoplasmic Reticulum (ER)(ER)
ER
Endoplasmic Reticulum, Endoplasmic Reticulum, the ERthe ER
Smooth ERSmooth ER makes lipids. makes lipids. Detoxifies blood and Detoxifies blood and
poisons in liverpoisons in liver used to make used to make
membranesmembranes
Rough ERRough ER ((ribosomesribosomes)) makes proteins. makes proteins. exports proteins or movement to different exports proteins or movement to different
parts of cellparts of cell
ribosome
Golgi Body (Golgi Stack)Golgi Body (Golgi Stack)
Golgi
Golgi BodyGolgi Body Sorts proteins. Sorts proteins. Sent to:Sent to:
Secreted (released Secreted (released from cell)from cell)
Plasma MembranePlasma Membrane Membrane bound Membrane bound
organelles.organelles.
Pancreas?
Secretes INSULIN.
Not working? Diabetes.
LysosomeLysosome
Lysosome
Lysosomes and Lysosomes and peroxisomesperoxisomes
Membrane Bound*Membrane Bound* Store or destroy Store or destroy
waste.waste. Lysosomes are Lysosomes are
acidic, like your acidic, like your stomach.stomach.
VacuoleVacuole
Vacuole
VacuoleVacuole
Large in plants.Large in plants. Stores water Stores water
ChloroplastsChloroplasts
Chloroplast
ChloroplastsChloroplasts
Membrane Bound*Membrane Bound* Sunlight energy is Sunlight energy is
converted to sugar.converted to sugar. Filled with Filled with
chlorophyll, making chlorophyll, making plants GREEN!plants GREEN!
MitochondriaMitochondria
Mitochondria
MitochondriaMitochondria
Membrane Bound* Membrane Bound* (double membrane)(double membrane)
Sugar is BURNED, Sugar is BURNED, making ATP making ATP (Energy).(Energy).
PLANTS and PLANTS and ANIMALS get their ANIMALS get their ENERGY HERE!!ENERGY HERE!!
ChromosomesChromosomes
DNA, instructions for DNA, instructions for making proteinsmaking proteins
Proteins manage the Proteins manage the chemical reactions chemical reactions that are YOU!that are YOU!
Plant or Animal Cell?
RibosomesRibosomes
Make proteinsMake proteins In cytoplasm or In cytoplasm or
studding the surface studding the surface of the rough ER.of the rough ER.
Compare Plant Compare Plant and and
Animal CellsAnimal Cells
Look at your notes packet, What do you Look at your notes packet, What do you see are similar? see are similar?
What are different?What are different?
Plant Cells Animal Plant Cells Animal CellsCells
ChloroplastsChloroplasts Centrioles Centrioles
Cell WallCell Wall
Larger VacuoleLarger Vacuole
Composition of Cell Composition of Cell MembraneMembrane
Proteins
Carbohydrates
Phosphate heads
Lipid tails
Phospholipid Bilayer
or fluid mosaic modelor fluid mosaic model Called this because the membrane is fluidCalled this because the membrane is fluid two layers of phospholipids two layers of phospholipids
hydrophilic (or polar) head hydrophilic (or polar) head two long, hydrophobic (or nonpolar) tails. two long, hydrophobic (or nonpolar) tails.
This means the heads like to be near water This means the heads like to be near water (face out) while the tails prefer to be away (face out) while the tails prefer to be away from water (face towards each other) from water (face towards each other)
This can be seen when oil (nonpolar) is mixed This can be seen when oil (nonpolar) is mixed with water (polar) with water (polar)
Building different Building different membranesmembranes is one way is one way different cell types are made.different cell types are made.
Selectively PermeableSelectively Permeablehttp://http://
www.indiana.ewww.indiana.edu/~pdu/~p
hys215/hys215/lecture/lecture/lecnotes/lecnotes/lecgraphics/lecgraphics/diffusion2.gifdiffusion2.gif
http://www.ricochetprod.com/elearning/membrane/semipermeable_membrane.html
DiffusionDiffusion
Movement of molecules from a high concentration to a low concentration
When molecules spread out to an even concentration
Concentration GradientConcentration Gradient
Concentration difference on two sides of Concentration difference on two sides of a barriera barrier
High
Low
EquilibriumEquilibrium
An even concentration on both sides of An even concentration on both sides of the membranethe membrane
ExamplesExamples
PerfumePerfume GasGas Dye in waterDye in water
Ultimately the Ultimately the molecules want to molecules want to create a balance or create a balance or EQUILIBRIUMEQUILIBRIUM
Try ThisTry This
In a diffusion situation:In a diffusion situation:
OsmosisOsmosis
Movement of Movement of water from a high water from a high to a low to a low concentration, in concentration, in an attempt to even an attempt to even outout
ExamplesExamples
Soaking rice in water – little water, lots of Soaking rice in water – little water, lots of starch so water goes in.starch so water goes in.
Wants to create an EQUILIBRIUMWants to create an EQUILIBRIUM
Solve:Solve:
10 % Iodine90% H2O
100 % Water
5 % Iodine95% H2O
95 % H2O5% Iodine
PlasmolysisPlasmolysis(type of osmosis)(type of osmosis)
A special case involving osmosis and plantsA special case involving osmosis and plants When water is drawn out of the cell causing the When water is drawn out of the cell causing the
cell membrane to shrink.cell membrane to shrink.
Active and Passive Active and Passive TransportTransport
Both provide movement within or between Both provide movement within or between cellscells
Passive transport – takes NO Passive transport – takes NO energy. (like flowing energy. (like flowing downhill)downhill)
Only works from High to Low Only works from High to Low concentrations!concentrations!
Channels – only let certain things throughChannels – only let certain things through
http://bcs.whfreeman.com/thelifewire/content/chp05/0502001.html
Active transport – Active transport – Requires energy! (like Requires energy! (like walking uphill)walking uphill)
proteins- Use energy (ATP) to move proteins- Use energy (ATP) to move substancessubstances
channels – May transport two molecules channels – May transport two molecules one is being concentrated while other is one is being concentrated while other is diffusing (flowing from High to Low)diffusing (flowing from High to Low)
http://www.biologie.uni-hamburg.de/b-online/library/biolohttp://www.biologie.uni-hamburg.de/b-online/library/biology107/bi107vc/fa99/terry/images/ATPpumA.gifgy107/bi107vc/fa99/terry/images/ATPpumA.gif
ReviewReview
Endocytosis (UPTAKE)Endocytosis (UPTAKE)
A “bubble” of membrane pinches off A “bubble” of membrane pinches off Moving large particles INTO the cell.Moving large particles INTO the cell.
Exocytosis (secretion) – Exocytosis (secretion) – think opposite of think opposite of endocytosis (like EXIT)endocytosis (like EXIT) A “bubble” of membrane fuses with the cell A “bubble” of membrane fuses with the cell
membranemembrane Large particles move OUT of the cellLarge particles move OUT of the cell..
Inside Outside
http://www.youtube.com/watch?v=4gLtk8Yc1Zc&feature=related
Diabetes:Diabetes:
Pancreas produces insulin in response to Pancreas produces insulin in response to amount of glucose (sugar) consumed by amount of glucose (sugar) consumed by the person.the person.
Activate insulin receptors to increase Activate insulin receptors to increase glucose uptake by activating the plasma glucose uptake by activating the plasma membrane glucose transporters (GLUTs)membrane glucose transporters (GLUTs)
These glucose transporters are then able to These glucose transporters are then able to channel glucose from the blood into the cell.channel glucose from the blood into the cell.
If unable to activate insulin receptor then If unable to activate insulin receptor then leads to diabetes type 2. Cells are unable leads to diabetes type 2. Cells are unable to take up glucose. to take up glucose.
Diabetes type 1 is caused by autoimmune Diabetes type 1 is caused by autoimmune destruction of the cells needed to produce destruction of the cells needed to produce the insulin in the pancreas.the insulin in the pancreas.