Membrane Transport

Question 1

What are the two types of channel proteins? What are the characteristics of each?

Answer 1

Leakage channels (always open)

Gated channels (controlled by chemical or electrical signals)

Question 2

Characteristics of carrier and channel proteins

Answer 2

Exhibit specificity

Are saturable (rate is determined by number of carriers or channels)

Can be regulated in terms of activity and quantity

Question 3

Hypertonic

Answer 3

A solution having greater solute concentration than that if the cytosol

Question 4

How does Ca2+ ATPase work?

Answer 4

1. Calcium and ATP binding
2. Phosphorylation of aspartate
3. Conformational change
4. Calcium release
5. Dephosphorylation
6. Conformational change

Question 5

Sodium- potassium pump. Type of transport

Answer 5

Active; Antiport

Question 6

Membrane permeability equation

Answer 6

Membrane permeability = lipid solubility/ molecular size

Question 7

Types of Membrane Transport

Answer 7

Simple Diffusion

Carrier- mediated transport

Vesicular Transport

Question 8

Channel mediated facilitated diffusion

Answer 8

Through a channel protein; mostly ions

Selected on basis of size and charge

Question 9

Types of simple diffusion

Answer 9

Through lipid bilateral

osmosis

Question 10

Transmembrane integral proteins transport specific ____________ proteins.

Answer 10

polar

Question 11

Examples of antiport carriers

Answer 11

1. Na+- H+
2. Na+- Ca2+

Question 12

Edematous patients

Answer 12

Patients that are swollen because of water is retained in their tissues

Question 13

When solutions of different osmolarity are separated by a membrane, osmosis occurs until _______ is reached.

Answer 13

Equilibrium

Question 14

Types of vesicular transport

Answer 14

Endocytosis

Exocytosis

Question 15

Certain lipophobic molecules use _____ proteins or _______ proteins.

Answer 15

Carrier; channel

Question 16

Changing the _______ of the lipid layer can increase or decrease membrane permeability.

Answer 16

composition

Question 17

How does the sodium potassium pump work?

Answer 17

1. Sodium and ATP binding
2. Phosphorylation of aspartate
3. Conformational change
4. Sodium release; potassium binding
5. Dephosphorylation and conformational change
6. Potassium release

Question 18

What substances are membrane permeable?

Answer 18

Gases, small uncharged polar molecules

Question 19

What substance are not membrane permeable?

Answer 19

Large uncharged polar molecules, ions, and charged polar molecules

Question 20

The sodium-potassium pump maintains __________________ gradients essential for functions of muscle and nerve tissues.

Answer 20

Electrochemical

Question 21

What does secondary transport depend on?

Answer 21

An ion gradient created by primary active transport

Question 22

Examples of isotonic solutions

Answer 22

0.9 % Saline

5% Glucose

Question 23

Isotonic

Answer 23

A solution with the same solute concentration as that of the cytosol

Question 24

H+-K+ ATPase

Answer 24

Active; Antiport

Question 25

Two types of Secondary active transport

Answer 25

Symport system; Antiport system

Question 26

Which type of transport always transports more than one substance at a time?

Answer 26

Secondary Active transport

Question 27

What is facilitated diffusion using channel proteins?

Answer 27

Aqueous channels formed by transmembrane proteins that selectively transport ions or water

Question 28

Osmolarity

Answer 28

The measure of the total concentration of solute particles

Question 29

Water diffuses through water channels called \_\_\_\_\_\_\_\_\_.

Answer 29

Aquaporins

Question 30

\_\_\_\_\_\_ particles displace water molecules.

Answer 30

Solute

Question 31

Osmosis

Answer 31

Movement of solvent from a high concentration to a low concentration

Question 32

Substances move across the plasma membrane by passive processes, which depend on the _______ of molecules, and by active processes, which depend on the use of \_\_\_\_\_\_\_\_\_.

Answer 32

Kinetic energy; cellular energy

Question 33

Calcium ATPase

Answer 33

Active; Uniport

Question 34

Binding of _________ causes shape change in carrier.

Answer 34

Substrate

Question 35

Fick’s Law of Diffusion

Answer 35

Rate of diffusion= (surface area x concentration gradient x membrane permeability)/membrane thickness

Question 36

Tonicity

Answer 36

The ability of a solution to cause a cell to shrink or swell

Question 37

What is Brownian Motion?

Answer 37

the random motion of particles suspended in a fluid resulting from their collision with the fast-moving molecules in the fluid

Question 38

Energy from the hydrolysis of ________ causes shape change in transport protein so that bound solute ions are pumped across the membrane.

Answer 38

ATP

Question 39

Hypotonic

Answer 39

A solution having lesser solute concentration that that of the cytosol

Question 40

Which forms of transport require ATP?

Answer 40

Active transport

Question 41

How does the ATP-driven Na+-K+ pump store energy?

Answer 41

By creating a steep concentration gradient for the sodium entry into the cell

Question 42

Which types of molecules can participate in simple diffusion across the membrane?

Answer 42

Fat soluble

Question 43

Factors affecting rate of diffusion through a cell membrane.

Answer 43

Lipid solubility Molecular size Concentration gradient Membrane surface area Composition of lipid layer

Question 44

Where is the Na-K pump located?

Answer 44

In all plasma membranes

Question 45

Types of carrier-mediated Transport

Answer 45

Facilitated diffusion Primary active transport Secondary Active transport

Question 46

Examples of Symport Carriers

Answer 46

1. Na+K+ -2Cl- 2. Na+- glucose 3. Na- + amino acids 4. Na+- bile salts 5. Na+ choline uptake 6. Na+ neaurotransmitter uptake 7. HCo3- Cl-

Question 47

Active transport

Answer 47

Moves solutes HYDROLYSIS against a concentration gradient

Question 48

H+- ATPase or proton pump

Answer 48

Active; Uniport