1. Chapter 7: Cell Membrane Structure
AP Biology
Chapter 7:
Cell Membrane Structure

2. Fig: 7.7

3. LE 7-2
WATER
Hydrophilic
head
Hydrophobic
tail
WATER

4. Hydrophobic region of protein
LE 7-3
Hydrophilic region
of protein
Phospholipid
bilayer
Hydrophobic region of protein

5. Proteins of the Membrane

6. Fig: 7.7

7. Transport Enzymatic activity Signal transduction Signal Enzymes
LE 7-9a
Signal
Enzymes
Receptor
ATP
Transport
Enzymatic activity
Signal transduction

8. Cell-cell recognition Intercellular joining Attachment to the
LE 7-9b
Glyco-
protein
Cell-cell recognition
Intercellular joining
Attachment to the
cytoskeleton and extra-
cellular matrix (ECM)

9. Cholesterol of the Membrane

10. Movement of phospholipids
LE 7-5a
Lateral movement
(~107 times per second)
Flip-flop
(~ once per month)
Movement of phospholipids

11. Extracellular layer Proteins Knife Plasma membrane Cytoplasmic layer
LE 7-4
Extracellular
layer
Proteins
Knife
Plasma
membrane
Cytoplasmic
layer
Extracellular layer
Cytoplasmic layer

12. Cell – to – Cell Recognition

13. LE 7-15a
EXTRACELLULAR
FLUID
Channel protein
Solute
CYTOPLASM

14. LE 7-15b
Carrier protein
Solute

15. Diffusion

16. Osmosis

17. LE 7-13 Hypotonic solution Isotonic solution Hypertonic solution
Animal
cell
H2O
H2O
H2O
H2O
Lysed
Normal
Shriveled
Plant
cell
H2O
H2O
H2O
H2O
Turgid (normal)
Flaccid
Plasmolyzed

18. Water Potential

19. LE 7-15a
EXTRACELLULAR
FLUID
Channel protein
Solute
CYTOPLASM

20. LE 7-16 Cytoplasmic Na+ bonds to the sodium-potassium pump
EXTRACELLULAR
FLUID
[Na+] high
[K+] low
Na+
Na+
Na+
Na+
Na+
Na+
Na+
Na+
[Na+] low
[K+] high
ATP P
Na+ P
CYTOPLASM
ADP
Cytoplasmic Na+ bonds to
the sodium-potassium pump
Na+ binding stimulates
phosphorylation by ATP.
Phosphorylation causes
the protein to change its
conformation, expelling Na+
to the outside. K+ K+ K+ K+ K+ P P K+
Extracellular K+ binds
to the protein, triggering
release of the phosphate
group.
Loss of the phosphate
restores the protein’s
original conformation.
K+ is released and Na+
sites are receptive again;
the cycle repeats.

21. Facilitated diffusion
LE 7-17
Passive transport
Active transport
ATP
Diffusion
Facilitated diffusion

22. Cell Voltage Gradient

23. Fig: 7.18

24. Fig: 7.19

25. Phagocytosis & Pinocytosis

26. RECEPTOR-MEDIATED ENDOCYTOSIS
LE 7-20c
RECEPTOR-MEDIATED ENDOCYTOSIS
Coat protein
Receptor
Coated
vesicle
Coated
pit
Ligand
A coated pit
and a coated
vesicle formed
during
receptor-
mediated
endocytosis
(TEMs).
Coat
protein
Plasma
membrane
0.25 µm