Cell Physiology - Membrane Transport

Question 1

What are the 3 components of the plasma membrane?

Answer 1

• Membrane Lipids
• Membrane Proteins
• Membrane Carbohydrates

Question 2

What are the 3 components of a lipid?

Answer 2

• Phospholipid
• Cholesterol
• Glycolipids

Question 3

What is the function of cholesterol in the plasma membrane?

Answer 3

• strengthens membrane

- stabilizes membrane against temperature extremes

Question 4

Glycolipids help to form the ____, which is the “coating of sugar” on cell’s surface.

Answer 4

Glycocalyx

Question 5

____ proteins are embedded within and extend across the phospholipid bilayer.

Answer 5

Integral

Question 6

____ proteins are loosely attached to the external or interior surfaces of the membrane. (Not embedded in lipid bilayer)

Answer 6

Peripheral

Question 7

The 2 types of passive processes of membrane transport are ____ and ____.

Answer 7

• diffusion

- osmosis

Question 8

Passive membrane transport depends on substances moving ____ the concentration gradient.

Answer 8

down

High to low concentration

Question 9

What 3 things determine the rate of transport in diffusion?

Answer 9

• “steepness” of concentration gradient
• Temperature (more movement with higher temp)
• Molecular size

Question 10

In ____ diffusion, small nonpolar solutes pass between phospholipid molecules.

Answer 10

Simple

Question 11

True or False: In simple diffusion, molecules continue to move as long as the concentration gradient exists.

Answer 11

TRUE

Question 12

In ___ diffusion, small charged or polar solutes require assistance from plasma membrane proteins.

Answer 12

Facilitated

Question 13

Channel-mediated diffusion is important in normal function of ____ and ___ cells

Answer 13

muscle, nerve

Question 14

How are small polar molecules transported across plasma membrane in carrier-mediated diffusion?

Answer 14

Molecule binds to carrier protein, causing it to change shape and move molecule across membrane.

Question 15

What are the 2 ways water can cross the membrane in osmosis?

Answer 15

1. Slips between molecules of phopholipid bilayer

2. Moves thru integral protein water channels (aquaporins)

Question 16

When does osmosis stop?

Answer 16

when there is equal concentration of water inside and outside of the cell (Equilibrium)

Question 17

_____ transport uses energy directly from breakdown of ATP to move solute across membrane.

Answer 17

Primary active

Question 18

What are the 2 types of primary active tranport?

Answer 18

• Ion pumps

- Sodium-potassium pump

Question 19

Ca2+ pumps in the membrane of erythrocytes function to remove intracellular Ca2+ to prevent _______ from the accumulated calcium.

Answer 19

cell rigidity

Question 20

How are ions exchanged in the sodium-potassium pump?

Answer 20

2K+ move in while 3Na+ move out

Question 21

Na/K Pump continuously exports Na+ out and moves K+ in as long as … ?

Answer 21

as long as there is ATP.

Question 22

What are the 2 types of secondary active transport?

Answer 22

• Symport (substances moved in same direction)

- Antiport (substances move in opposite direction)

Question 23

In what active process does a cell engulf a large particle that is external to the cell?

Answer 23

Phagocytosis

“cellular eating”

Question 24

What active process involves the internalization of droplets of interstitial fluid containing dissolved molecules?

Answer 24

Pinocytosis

“cellular drinking”

Question 25

What active process uses receptors on the plasma membrane to bind molecules within interstitial fluid and bring the molecules into the cell?

Answer 25

Receptor-mediated endocytosis

Question 26

In ____ transport, energy is used from a 2nd substance moving down its gradient in order to move substance across gradient.

Answer 26

Secondary active