AP Biology Chapter 7: Cell Membrane Structure. Fig: 7.7.

AP Biology

Chapter 7:Cell Membrane Structure

Fig: 7.7

LE 7-2

Hydrophilichead

Hydrophobictail

WATER

WATER

LE 7-3

Hydrophilic regionof protein

Hydrophobic region of protein

Phospholipidbilayer

Proteins of the Membrane

Fig: 7.7

LE 7-9a

EnzymesSignal

ReceptorATP

Transport Enzymatic activity Signal transduction

LE 7-9b

Glyco-protein

Cell-cell recognition Intercellular joining Attachment to thecytoskeleton and extra-cellular matrix (ECM)

Cholesterol of the Membrane

LE 7-5a

Lateral movement(~107 times per second)

Flip-flop(~ once per month)

Movement of phospholipids

LE 7-4

Knife

Cytoplasmic layerExtracellular layer

Cytoplasmic layer

Plasmamembrane

Extracellular layer

Proteins

Cell – to – Cell Recognition

LE 7-15a

EXTRACELLULARFLUID

Channel protein Solute

CYTOPLASM

LE 7-15b

Carrier protein Solute

Diffusion

Osmosis

LE 7-13

Animalcell

Lysed

H2O H2O H2O

Normal

Hypotonic solution Isotonic solution Hypertonic solution

H2O

Shriveled

H2OH2OH2OH2OPlantcell

Turgid (normal) Flaccid Plasmolyzed

Water Potential

LE 7-15a

EXTRACELLULARFLUID

Channel protein Solute

CYTOPLASM

LE 7-16

Cytoplasmic Na+ bonds tothe sodium-potassium pump

CYTOPLASMNa+

[Na+] low[K+] high

Na+

Na+

EXTRACELLULARFLUID

[Na+] high[K+] low

Na+

Na+

Na+

ATP

ADP

P

Na+ binding stimulatesphosphorylation by ATP.

Na+

Na+

Na+

K+

Phosphorylation causesthe protein to change itsconformation, expelling Na+

to the outside.

P

Extracellular K+ bindsto the protein, triggeringrelease of the phosphategroup.

PP

Loss of the phosphaterestores the protein’soriginal conformation.

K+ is released and Na+

sites are receptive again;the cycle repeats.

K+

K+

K+

K+

K+

LE 7-17

Diffusion Facilitated diffusion

Passive transport

ATP

Active transport

Cell Voltage Gradient

Fig: 7.18

Fig: 7.19

Phagocytosis & Pinocytosis

LE 7-20c

Receptor

RECEPTOR-MEDIATED ENDOCYTOSIS

Ligand

Coatedpit

Coatedvesicle

Coat protein

Coat protein

Plasmamembrane

0.25 µm

A coated pitand a coatedvesicle formedduringreceptor-mediatedendocytosis(TEMs).