ap chapter 6 notes 2

7/28/2019 AP Chapter 6 Notes 2

1/34

Chapter 6 notes

A Tour of the Cell


2/34

Concept 6.1Light Microscope: visible light is passed

through a specimen and then through

glass lenses

- magnification

- resolving power


3/34

Concept 6.1Electron Microscope: focuses beams of

electrons through the specimen or onto

its surface.- transmission electron microscope(TEM): used to study the internalultrastructure of cells

- Scanning electron microscope (SEM):used for detailed study of the surface


4/34

Concept 6.1Cell Fractionation: take cells apart and

study the fcn. of organelles

- use of ultracentrifuges

-fig. 7.3


5/34

Concept 6.2All cells have several basic features:

- have a plasma membrane

- cytsol: semifluid substance thatcontains organelles

- chromosomes/DNA

- ribosomes


6/34

Concept 6.2Prokaryotic cell vs. Eukaryotic cell

- nucleiod vs. nucleus

- eukaryotes are 10X bigger

Larger organisms do not have larger cells,just more cells


7/34

Concept 6.2 PiliNucleoid

RibosomesPlasma membrane

Cell wallCapsule

Flagella

Bacterialchromosome

(a) A typical rod-shapedbacterium (b) A thin section

through thebacteriumBaci l lus

coagulans

(TEM)

0.5

m


8/34

Concept 6.2Internal membranes compartmentalize

the fcns. of a eukaryotic cell

- membranes consist of a double layerof phospholipids and other lipids;attached to the surface are proteins


9/34

Concept 6.2 TEM of a plasmamembrane(a)

(b) Structure of the plasma membrane

Outside of cell

Inside of

cell 0.1 m

HydrophilicregionHydrophobic

regionHydrophilic

regionPhospholipid Proteins

Carbohydrate side chain


10/34

Concept 6.2


11/34

Concept 6.3The nucleus is a double membrane

- inside is lined by the nuclear lamina(protein filaments that help the nucleusmaintain shape)

- DNA is organized w/ proteins into

chromatin


12/34

Concept 6.3As a cell prepares to divide, the chromatin

fibers coil up into chromosomes

Nucleolus: ribosomal RNA is synthesizedw/ proteins into ribosomal subunits


13/34

Concept 6.3Nucleolus Nucleus

Rough

ER

Nuclear lamina(TEM)

Close-up ofnuclearenvelope

1 mRibosome

Porecomplex

Nuclearpore

Outer membraneInner membraneNuclear envelope:

Chromatin

Surface of

nuclearenvelope

Pore complexes(TEM)


14/34

Concept 6.3Ribosomes: organelles that carry out

protein synthesis

- cells that have high rates of proteinsynthesis have several ribosomes

- free ribosomes:

- suspended in the cytosol- fcn. within the cell


15/34

Concept 6.3- bound ribosomes:

- attached to the outside of the ER

or nuclear envelope

- protein insertion into membranes,packaging (lysosomes), or export

from cell (excretion)


16/34

Concept 6.4Endomembrane system: made up of

many different membranes

Endoplasmic reticulum: manufacturesmembranes and performs many otherbiosynthetic functions

- accounts for more than half the totalmembrane in many eukaryotic cells


17/34

Concept 6.4Smooth ER:

- surface lacks ribosomes

- synthesis of lipids, metabolism ofcarbohydrates, detoxification of drugsand poisons


18/34

Concept 6.4Rough ER:

- specialized cells secrete proteins

produced by ribosomes attached torough ER

- ex. Secretion of insulin in pancreas


19/34

Concept 6.4The Golgi apparatus finishes, sorts, and

ships cell products

- after leaving the ER, many transportvesicles travel to the Golgi

- consists of flattened sacs, called

cisternae


20/34

Concept 6.4A Golgi stack has distinct polarity

- cisface: receiving side, gets material

from the ER

- transface: shipping side, gives riseto vesicles that will travel to other sites


21/34

Concept 6.4


22/34

Concept 6.4Lysosomes are digestive compartments

- membrane-bound sac of enzymes that

digest macromolecules

- different enzymes digest differentmolecules

Many protists use lysosomes to digestfood through phagocytosis


23/34


24/34


25/34


26/34

Concept 6.4

Vacuoles have diverse fcns. in cellmaintenance

- food vacuole: formed by phagocytosis- contractile vacuole: pump excesswater out of a cell

- central vacuole: hold reserves oforganic compounds, disposal site forbyproducts, contains pigments


27/34

Concept 6.4


28/34


29/34

Concept 6.5

Mitochondria and chloroplasts areorganelles that convert energy that cells

can use for workMembrane proteins are not made by the

rough ER, but by free ribosomes

Organelles also contain DNA


30/34

Concept 6.5

Mitochondria: site of cellular respiration

- found in most all eukaryotic cells;

number of mitochondria is correlatedwith the cells metabolic activity

- enclosed in a double membrane

- outer layer is smooth, innercontains infoldings called cristae(gives a large surface area)


31/34

Concept 6.5

- mitochondrial matrix is enclosed inthe inner membrane

- contains many enzymes,mitochondrial DNA, and

ribosomes


32/34

Concept 6.5


33/34

Concept 6.5

Chloroplasts are specialized plantorganelles (contain chlorophyll)

- thylokoids: membranous system offlattened sacs (each stack is a grana)

- stroma: fluid outside the thylokoids

- contains chloroplast DNA andribosomes


34/34

Concept 6.5

ap chapter 6 notes 2

Documents