L3 - Passive membrane transport

Question 1

Membrane protein function

Answer 1

Membrane transport
Receptors
Enzymes
Adhesion
Identity

Question 2

Membrane transport

Answer 2

What goes in and out of cells

Question 3

Receptors

Answer 3

communicate to other cells and tissues

Question 4

Enzymes

Answer 4

Catalyse reactions

Question 5

Adhesion

Answer 5

Adhesion molecules connect adjacent cells

Question 6

Identity

Answer 6

Identitiy molecules give cells unique immune signature

Question 7

Passive movement

Answer 7

Doesnt require energy
High conc to low conc

Question 8

Flux

Answer 8

Rate at which passive movement occurs

Question 9

What does flux depend on

Answer 9

steepness of conc gradient
area of interface
type of molecules (large mlecules diffuse slower)
thickness of diffusion distance

Question 10

Simple diffusion

Answer 10

Small and non-polar substances e.g. O2, CO2
Steroid hormones, lipophilic drugs, water

Question 11

Facilitated diffusion

Answer 11

Polar substances e.g. glucose, amino acids
Via carrier proteins
Doesnt require energy

Question 12

Carrier protein (glucose)

Answer 12

1. Raised blood glucose creates chemical force for influx
2. Glucose binds to GLUT1 carrier, changes shape, and is released to the inside

Question 13

Through ion channels

Answer 13

Ions move across membrane via water filled pores of ion channels
1. High extracellular Na+ creates chemical force for influx
2. Small aqueous pores allow Na+ to flow down conc gradient

Question 14

Non-gated ion channels

Answer 14

Mostly open

Question 15

Ligand-gated ion channels

Answer 15

Open in response to chemical stimuli

Question 16

Mechanically gated ion channel

Answer 16

Open in response to mechanical stress applies to membrane

Question 17

Voltage-gated ion channel

Answer 17

Open in response to changes in membrane potential

Question 18

Osmotic diffusion

Answer 18

Water moving across membrane
Aquaporins allow for greater diffusion of water

Question 19

Isotonic

Answer 19

Solution has same conc of solute as inside a cell

Question 20

Hypotonic

Answer 20

Less conc of solute
Cell swells

Question 21

Hypertonic

Answer 21

More conc of solution
Cells shrinks

Question 22

Types of passive diffusion

Answer 22

1. Simple
2. Facilitated diffusion
3. Through ion channels