IASM 31 32: Membrane Transport and Excitability

Question 1

Steps of endocytosis

1. _______ bind to receptors on plasma cell membrane
2. Area coated with ligands form ________
3. Formation of ________ (coated vesicles)
4. Endosomes fuse with __________ to form secondary lysosomes
5. Ligands removed and absorbed into the cytoplasm
6. ____________________________ separate
7. _________ fuses with plasma membrane and receptors are again available for ligand binding

Answer 1

Steps of endocytosis

1. Ligands bind to receptors on plasma cell membrane
2. Area coated with ligands form deep pockets
3. Formation of endosomes (coated vesicles)
4. Coated vesicles fuse with primary lysosomes to form secondary lysosomes
5. Ligands removed and absorbed into the cytoplasm
6. Lysosomal and endosomal membranes separate
7. Endosome fuses with plasma membrane and receptors are again available for ligand binding

Question 2

Pinocytosis is responsible for transporting ____ into the cell. Phagocytosis is responsible for transporting _____ into the cell.

Answer 2

Pinocytosis: Fluid
Phagocytosis: Solid

Question 3

What is the resting membrane potential

Answer 3

-65mV

Question 4

What uses up 70% of ATP in the brain

Answer 4

Na K ATPase

Question 5

Compare Graded Potentials and Action Potentials

Depolarizing? Hyperpolarizing?

Answer 5

Graded VS Action

Depolarizing or Hyperpolarizing VS Always Depolarizing

Question 6

Compare Graded Potentials and Action Potentials

In terms of presence threshold value

Answer 6

No threshold value VS Need reach threshold before action potential begins

Question 7

Compare Graded Potentials and Action Potentials

In terms of intensity of depolarization

Answer 7

Amount of depolarization depends on intensity of stimulus VS All or none

Question 8

Compare Graded Potentials and Action Potentials

In terms of spread

Answer 8

Passive spread VS Potential at one site depolarizes the adjacent sites

Question 9

Compare Graded Potentials and Action Potentials

In terms of strength derease

Answer 9

Effect of membrane potential decreases with distance VS Entire membrane without decrease in strength

Question 10

Compare Graded Potentials and Action Potentials

In terms of refractory period

Answer 10

No refractory period VS Yes refractory period

Question 11

Compare Graded Potentials and Action Potentials

In terms of membrane

Answer 11

In most plasma membrane VS Only in excitable membranes