Membrane Function

Question 1

What are membranes fully permeable to?

Answer 1

Hydrocarbons, O2 and CO2

Question 2

What controls entry of substances into the cell?

Answer 2

Proteins.

Question 3

What are the modes of transport?

Answer 3

Passive and active transport.

Question 4

What is Tonicity?

Answer 4

The ability of an extracellular fluid to influence the uptake of water into a cell

Question 5

What does isotonic mean?

Answer 5

The conc is equal inside and outside of cell. An equilibrium position has been reached.

Question 6

If an animal cell becomes very hypotonic, what will happen?

Answer 6

It will burst.

Question 7

Plant cells are usually in what state?

Answer 7

Hypotonic.

Question 8

What is the name for the process of an animal cell when it shrinks through hypertonicity?

Answer 8

Crenation.

Question 9

If a plant cell is hypertonic, what happens to it, what is this called?

Answer 9

Plasmolysed, the cell membrane shrinks away from the cell wall.

Question 10

If a protein requires the use of a protein to be diffused across a membrane, what is it called?

Answer 10

Facilitated diffusion.

Question 11

Is facilitated diffusion passive or active transport?

Answer 11

Passive.

Question 12

What lines ion channels.

Answer 12

H2O molecules and Hydrophilic amino acids.

Question 13

Ion channels that are open all he time are responsible for?

Answer 13

Stabilising the membrane potential.

Question 14

What is the membrane potential?

Answer 14

The difference in voltage charge across membrane

Question 15

What happens if membrane potential changes?

Answer 15

The gate to the ion channel opens/closes.

Question 16

Where is Na+/K+ conc higher?

Answer 16

Na+ is higher outside cell

K+ is lower outside cell

Question 17

What does the conformational change caused by phosphorylation create?

Answer 17

2 K+ binding sites

Question 18

How does the asymmetric charge presented by membrane potentials arise?

Answer 18

Electrogenic pumps. Pump ions across the membrane.

Question 19

What can membrane potentials be used to do?

Answer 19

Transport other secondary solutes

Question 20

What does the movement of charged solutes depend on?

Answer 20

Concentration of solute and Charge of solute

Question 21

What do electrogenic pumps create?

Answer 21

An asymmetric distribution of ions, which provides a store of potential energy.

Question 22

How many types of endocytosis are there? What are they?

Answer 22

Receptor mediated endocytosis, Pinocytosis And phagocytosis

Question 23

When a vesicles containing nutrients for the cell approaches the cell, what happens in order for the vesicle to be taken up by the cell.

Answer 23

Endocytosis, the lipids of the vehicle’s PM merge with the lipids of the Cell’s PM.

Question 24

What are the types of exocytosis?

Answer 24

Regulated release via signals

Constitutive release