CellsCells

Chapter 3Chapter 3

Bio 156Bio 156

Fall 2006Fall 2006

What is the Cell Theory?What is the Cell Theory?

• All organisms are All organisms are made of cells.made of cells.

• The cell is the The cell is the smallest unit of smallest unit of life.life.

• New cells come New cells come from pre-existing from pre-existing cells.cells.

What are microscopes?What are microscopes? tools used to view cellstools used to view cells

• Compound light Compound light microscope: microscope: light rays light rays focused by lenses, focused by lenses, viewed by the eye, viewed by the eye, magnifies up to 1000X magnifies up to 1000X

Dissecting microscope:Dissecting microscope:

For observing For observing surface details surface details of objects, of objects, magnifies up to magnifies up to 30X30X

Penny

Electron microscopesElectron microscopes For viewing For viewing

details, details, magnifies magnifies 1,000,000X1,000,000X

TEMSurface of a cell, cilia

How are cells classified?How are cells classified?according to their internal according to their internal

organization?organization? What structures do all cells have?What structures do all cells have?

Cell or plasma membranes:Cell or plasma membranes: living living phospholipid bilayer and associated proteins phospholipid bilayer and associated proteins

Internal organization of cells cont…..Internal organization of cells cont…..

Plant cellsPlant cells also have a rigid cell wall also have a rigid cell wall made of cellulosemade of cellulose

Cytoplasm: Cytoplasm: a semifluid gel inside the a semifluid gel inside the cell cell that contain cell contentsthat contain cell contents

What are Eukaryotic Cells?What are Eukaryotic Cells? Have a “true nucleus”, plant Have a “true nucleus”, plant

and animal cellsand animal cells• What are What are

organelles?organelles? "little organ", "little organ", cellular structures cellular structures that perform that perform specific functionsspecific functions

• What does the What does the nucleus do?nucleus do? control center of control center of the cellthe cell

What are prokaryotic cells? What are prokaryotic cells? “before" the nucleus (bacteria)“before" the nucleus (bacteria)

DNA:DNA: single circular DNA in single circular DNA in a nuceloid regiona nuceloid region

Ribosomes:Ribosomes: enzymes enzymes that synthesize proteinsthat synthesize proteins

Cell membrane:Cell membrane: regulates transport in/out regulates transport in/out of the cellof the cell

CCell wallell wall for strength, for strength, may have a capsule or may have a capsule or slime layerslime layer

Bacillus polymyxa

How does cell structure reflect cell How does cell structure reflect cell function?function?

Simple cuboidal epithelium (400x) is made up Simple cuboidal epithelium (400x) is made up of one layer of cube-shaped cells.  These cells of one layer of cube-shaped cells.  These cells frequently make up the tubes of your body.frequently make up the tubes of your body.

How does cell structure reflect cell function…..How does cell structure reflect cell function…..

Blood Cells Blood Cells Why do you think Red Blood Cells Why do you think Red Blood Cells

don’t have a nucleus and White Blood don’t have a nucleus and White Blood Cells do? Cells do?

(hint: think about their functions)(hint: think about their functions)

How does cell structure reflect cell function…How does cell structure reflect cell function…

Skeletal muscle (400x) is striatedSkeletal muscle (400x) is striated What is the function of these cells? What is the function of these cells? Why do you think these are long Why do you think these are long

cells?cells?

http://www.mhhe.com/biosci/ap/histology_mh/skmuscls.jpg

How does cell structure reflectcell function…How does cell structure reflectcell function…

Plant Cell Anacharis (Plant Cell Anacharis (ElodeaElodea) leaf cells ) leaf cells (1000x).  (1000x). 

What do you think is the function of What do you think is the function of these cells?  these cells? 

How is the function dependent on the How is the function dependent on the structure?structure?

How does cell structure reflect cell function…How does cell structure reflect cell function…

Potato cells with stained leucoplasts Potato cells with stained leucoplasts (100x).  (100x).  • The leucoplasts (starch storage units) have The leucoplasts (starch storage units) have

been stained with gram iodine (stains for been stained with gram iodine (stains for starch)starch)

What limits cell size?What limits cell size?Surface area-to-volume ratio needs to be Surface area-to-volume ratio needs to be

greater for an exchange of materialsgreater for an exchange of materials

Microvilli: some cells increase surface area by micro-extensions called microvilli

http://distance.stcc.edu/AandP/AP/imagesAP2/digestion/microvilli.jpg

What is a plasma membrane made of? What is a plasma membrane made of? (how is a cell membrane like a (how is a cell membrane like a

house?)house?) • Phospholipids:Phospholipids:

a. polar headsa. polar heads (hydrophilic or water (hydrophilic or water soluble) soluble)

bb. . nonpolar tailsnonpolar tails (hydrophobic or not (hydrophobic or not water soluble)water soluble)

• Cholesterol: Cholesterol: gives gives strength to the cell strength to the cell membranemembrane

• Proteins: Proteins: transport, transport, communicationcommunication

What is the fluid-mosaic model of the What is the fluid-mosaic model of the cell membrane?cell membrane?

• How is itHow is it fluid?fluid? (flows, pliable) (flows, pliable) phospholipid bilayerphospholipid bilayer

• How is it a mosaic?How is it a mosaic? proteins partially or proteins partially or wholly embeddedwholly embedded

What are channel What are channel proteins? Space where proteins? Space where a substance moves a substance moves across the membraneacross the membrane

What are carrier proteins?What are carrier proteins?

Combine with a substance andCombine with a substance and

help it move across the help it move across the membranemembrane

http://www.aber.ac.uk/gwydd-cym/graffeg/biolgell/cludiant/sianel.gif

What are receptors? What are receptors? SSpecific shape that allows a pecific shape that allows a molecule to bind to it, ex) hormonemolecule to bind to it, ex) hormone

What are glycoproteins?What are glycoproteins? For cell to cell identificationFor cell to cell identification

http://www.emc.maricopa.edu/faculty/farabee/BIOBK/5_11.jpg

How are membranes selectively How are membranes selectively permeablepermeable??

Allows sAllows some molecules to pass through ome molecules to pass through

and not othersand not others What is passive What is passive

transport?transport? Doesn't need energy Doesn't need energy

to happen, goes with to happen, goes with concentration concentration gradientgradient

What is diffusion? What is diffusion? Movement of Movement of molecules from high molecules from high to low concentrationto low concentration

http://www.biology.arizona.edu/cell_bio/problem_sets/membranes/graphics/CHANNEL.GIF

What is osmosis? What is osmosis? Diffusion of water into and out of cellsDiffusion of water into and out of cells

• What is a solute?What is a solute? usually a solid usually a solid• What is a solvent?What is a solvent? usually a liquid usually a liquid • Define tonicityDefine tonicity: based on concentrations of solutes: based on concentrations of solutes

What are isotonic solutions?What are isotonic solutions? Same concentration of solutes on either side of Same concentration of solutes on either side of the membranethe membrane

http://www.cat.cc.md.us/courses/bio141/lecguide/unit4/metabolism/growth/images/isotonicanim.gif

What are hypotonic solutions?What are hypotonic solutions?

Low solutes in solution, water enters the Low solutes in solution, water enters the cell, hemolysiscell, hemolysis

http://images.google.com/imgres?imgurl=http://www.cat.cc.md.us/courses/bio141/lecguide/unit4/metabolism/growth/images/hypotonicanim.gif&imgrefurl=http://www.cat.cc.md.us/courses/bio141/lecguide/unit4/metabolism/growth/hypotonicanim.html&h=290&w=362&sz=357&tbnid=lOPoZ-_M4ysJ:&tbnh=93&tbnw=117&hl=en&start=2&prev=/images%3Fq%3Dosmosis%2Banimation%26svnum%3D10%26hl%3Den%26lr%3D

What are hypertonic solutions?What are hypertonic solutions?

High solutes in solution, causes water to High solutes in solution, causes water to leave leave the cell (water follows salt), crenationthe cell (water follows salt), crenation

http://www.cat.cc.md.us/courses/bio141/lecguide/unit4/metabolism/growth/images/hypertonicanim.gif

What is turgor pressure? What is turgor pressure? PPlant cells swell in response to a lant cells swell in response to a

hypotonic solutionhypotonic solution

Put some wilted celery in a glass of cool water. If it has not wilted too much, it will become stiff again. This is because of turgor pressure when the plant cell vacuoles become filled with water, push against the cell walls and become firm.

What is facilitated transport?What is facilitated transport? Carrier proteins assist movement of Carrier proteins assist movement of

specific molecules specific molecules

What isWhat is aactive transport?ctive transport? Requires Requires AATP to move molecules against TP to move molecules against

their concentration gradienttheir concentration gradient

• What is the What is the Na-K pump?Na-K pump?

• Concentrates Concentrates more Namore Na++ outside, Koutside, K++ inside inside cell membranescell membranes

http://www.biologie.uni-hamburg.de/b-online/library/biology107/bi107vc/fa99/terry/images/ATPpumA.gif

What is Exocytosis or Endocytosis? What is Exocytosis or Endocytosis? Move materials outside or inside the Move materials outside or inside the

cell cell

http://www.stanford.edu/group/Urchin/GIFS/exocyt.gif

What is Phagocytosis?What is Phagocytosis?“Cell eating”, white blood “Cell eating”, white blood

cellscells

http://faculty.uca.edu/~johnc/leukocyto.gif

What isWhat is Pinocytosis?Pinocytosis? “Cell drinking”, root cells get water“Cell drinking”, root cells get water

http://images.google.com/imgres?imgurl=http://www.cat.cc.md.us/~gkaiser/biotutorials/eustruct/images/pinocyt.gif&imgrefurl=http://www.cat.cc.md.us/~gkaiser/biotutorials/eustruct/pinocyt.html&h=362&w=363&sz=55&tbnid=0qGkaPabQ3MJ:&tbnh=116&tbnw=117&hl=en&start=1&prev=/images%3Fq%3Dpinocytosis%2Banimation%26svnum%3D10%26hl%3Den%26lr%3D%26sa%3DG

What is receptor-mediated What is receptor-mediated endocytosis? endocytosis?

CCoated proteins attract specific oated proteins attract specific molecules to the cell surfacemolecules to the cell surface

http://srs.dl.ac.uk/VUV/home-page/hot-topics/graphics/uffig1.gif

Construction of the Cell Construction of the Cell MembraneMembrane

This is an interactive activityThis is an interactive activity Construction of the Cell MembraneConstruction of the Cell Membrane In this activity you will learn about In this activity you will learn about

the cell membrane structure by the cell membrane structure by assembling it. Interactive exercise assembling it. Interactive exercise from Wisc-Online. from Wisc-Online.

http://www.wisc-online.com/lrnobj/ap1/AP1101/index.html

How do internal structures carry How do internal structures carry out specific functions?out specific functions?

What are the What are the structures of the structures of the nucleus?nucleus? Nuclear Nuclear

membrane:membrane: has has nuclear pore spacesnuclear pore spaces

Nucleolus: Nucleolus: forms forms RNA and ribosomesRNA and ribosomes

Chromatin:Chromatin: all of all of the DNA the DNA

moleculesmolecules

What do ribosomes do?What do ribosomes do? Assemble proteinsAssemble proteins

What does endoplasmic reticulum What does endoplasmic reticulum (ER) do?(ER) do?

Makes and Makes and transports large transports large moleculesmolecules

Smooth ER:Smooth ER: enzymes make enzymes make lipids, steroidslipids, steroids

Rough ERRough ER with with ribosomes (RNA): ribosomes (RNA): have ribosomes have ribosomes for making proteinfor making protein

What does the Golgi apparatus What does the Golgi apparatus look like? look like?

Stacks of sacules (like Stacks of sacules (like pancakes)pancakes) What is its What is its

function?function? SStores and distributes tores and distributes

products from ERproducts from ER Processes, packages Processes, packages

and secretesand secretes Breaks off pieces as Breaks off pieces as

vesicles (small sac)vesicles (small sac)

What are Vacuoles? What are Vacuoles? Large membranous sacs for transport Large membranous sacs for transport

and storageand storage

• What do What do lysosomes do? lysosomes do?

• Digestive Digestive enzymes in enzymes in vesiclesvesicles

• What are What are Peroxisomes?Peroxisomes?

• Vesicles with Vesicles with enzymes that enzymes that destroy toxinsdestroy toxins

What are mitochondria? What are mitochondria? SSite for aerobic respiration, ite for aerobic respiration,

"burns food""burns food" ProducesProduces ATP ATP

“cell's “cell's powerhouse”powerhouse”

Cristae:Cristae: inner inner membrane membrane increases increases surface area for surface area for metabolismmetabolism

Matrix:Matrix: inner inner fluid-filled spacefluid-filled space

What are chloroplasts? What are chloroplasts? Organelles only found in plant cellsOrganelles only found in plant cells

PPhotosynthesis:hotosynthesis: use solar energy to make use solar energy to make carbohydrates carbohydrates

Thylakoids:Thylakoids: interconnected flattened sacs interconnected flattened sacs Grana:Grana: stacks of stacks of

thylakoids thylakoids (granny's (granny's pancakes)pancakes)

Stroma:Stroma: syrupy syrupy fluid filled space fluid filled space (syrup)(syrup)

What provides cells with structure for What provides cells with structure for support and movement?support and movement?

Cytoskeleton?Cytoskeleton? interconnected interconnected microtubules and microtubules and microfilamentsmicrofilaments CCilia:ilia: small whips, small whips,

move cell, or fluids move cell, or fluids across a surfaceacross a surface

FFlagella:lagella: larger whip, larger whip, moves cell like an oar moves cell like an oar on a boaton a boat

Centrioles Centrioles in animal cells for spindle in animal cells for spindle fibers during mitosis, pull fibers during mitosis, pull chromosomes apartchromosomes apart

How do cells use and transform matter How do cells use and transform matter and energy?and energy?

• What are reactants? What are reactants? participate in a reaction, participate in a reaction, ex) A + B -> ex) A + B -> (enzyme)(enzyme)

• What are products?What are products? result from a reaction, result from a reaction, ex) C + Dex) C + D

•What are metabolic pathways? When one chemical reaction leads to

another ex) A + B -> C + D

What is Anabolism?What is Anabolism? Building up of larger Building up of larger

molecules, takes energy molecules, takes energy (endergonic)(endergonic)

What is Catabolism?Breaking down into smaller molecules, gives up energy (exergonic)

What is ATP?What is ATP? AA universal packet of energy universal packet of energy

used in cellsused in cells

ATP =ATP = adenosine triphosphate adenosine triphosphate (Adenine-ribose-P-P-P)(Adenine-ribose-P-P-P)

Exergonic:Exergonic: the energy currency of the the energy currency of the cellcell

ATP -> ADP + P + energyATP -> ADP + P + energy Endergonic:Endergonic:

ADP + P + energy -> ATPADP + P + energy -> ATP

What is cellular respiration?What is cellular respiration? CChemical reactions that produce hemical reactions that produce

ATP in cellsATP in cells• What is glycolysis? What is glycolysis?

bbreaks down glucose reaks down glucose (C(C66) -> 2 pyruvate (C) -> 2 pyruvate (C33) + ) + 2 ATP2 ATP

• Where does it take Where does it take place?place? in the cytoplasm, in the cytoplasm, in all cells, no Oin all cells, no O22 needed needed

• How does it get How does it get started? started? it needs 2 P it needs 2 P from 2 ATP activate from 2 ATP activate glucoseglucose

What is aerobic respiration?What is aerobic respiration? Respiration with oxygenRespiration with oxygen

Where does it take place? Where does it take place? Inside the mitochondria: yields 36-38 ATPInside the mitochondria: yields 36-38 ATP

What does the Krebs What does the Krebs cycle do?cycle do? 1) pyruvate is broken down to 1) pyruvate is broken down to OO22 + acetyl group (C + acetyl group (C22) -> ) ->

2 CO2 CO22 + 2 ATP + 2 ATP

2) NAD2) NAD++ and FAD + H and FAD + H22 -> ->

NADH and FADHNADH and FADH22 -> ->

electron transport systemelectron transport system

What does theWhat does the electron transport system electron transport system do?do?

Coenzyme Coenzyme carriers move carriers move electrons to electrons to make 32-34 ATPmake 32-34 ATP

What is fermentation? What is fermentation? AAlternative pathway of energy when lternative pathway of energy when

no oxygen is presentno oxygen is present

• GlycolysisGlycolysis first first• Alcoholic Alcoholic

fermentation:fermentation:• Glucose is broken Glucose is broken

down to pyruvate, down to pyruvate, then to Alcohol + then to Alcohol + COCO22 + 2 ATP + 2 ATP

• Used for: Used for: brewing, bakingbrewing, baking

What is lactic acid What is lactic acid fermentation?fermentation? Glucose -> pyruvate –> lactate + 2 Glucose -> pyruvate –> lactate + 2

ATP ATP • Used in making yogurt,Used in making yogurt,

sour cream, cheese, sour cream, cheese,

sauerkraut sauerkraut • In OIn O22 starved muscles, starved muscles,

oxygen debt:oxygen debt:

OO22 + lactic acid to + lactic acid to

pyruvate pyruvate

Need more help? Need more help?

For extra learning practice see links on Bb For extra learning practice see links on Bb under CH 3under CH 3

Read your test clues each night before you Read your test clues each night before you go to bed to help remember themgo to bed to help remember them

For extra credit fill out review sheet (1 pt) For extra credit fill out review sheet (1 pt) and write 15 multiple choice questions and and write 15 multiple choice questions and answer them (1 pt)answer them (1 pt)