Membrane Transport

Question 1

Oxygen can ____ into the cell along a concentration gradient, because oxygen is _____ and there is ___ energy in the oxygen gradient that fuels net movement of oxygen into the cell

Answer 1

Diffuse
Nonpolar
Potential

Question 2

Answer 2

Question 3

_____ is mostly hydrophobic, but has a hydroxyl group that allows it to orient in the bilayer in a specific way. _____ changes the fluidity and stability of the membrane.

Answer 3

Cholesterol

Question 4

The ____ the cholesterol content is, the more brittle the membrane is

Answer 4

Higher

Question 5

Answer 5

Question 6

Outside of the cell there is ___ concentrations of oxygen and glucose. Inside of the cell there is ___ concentration of oxygen and glucose

Answer 6

High
Low

Question 7

Both oxygen and glucose move into the cell ____ their concentration gradient. Because oxygen and glucose are used within the cell, the gradient is maintained.

Answer 7

Down

Question 8

Answer 8

Question 9

Oxygen is moving across the membrane by ___ ____, as the concentration gradient increases, diffusion flux _____.

Answer 9

Simple diffusion
Increases

Question 10

Glucose moves across the membrane by ___ ___. transport of glucose into the cell reaches a transport ____ when all the transporters are bound to glucose. The process cannot happen any faster.

Answer 10

Facilitated diffusion
Maximum

Question 11

Substances that are ___ and ____ can move across the membrane by simple diffusion

Answer 11

Small
Non-polar

Question 12

Substances that are ____ or ____ require proteins to get across the membrane by facilitated diffusion. The gradient still provides the energy for transport, but this process _____ when all of the transporters are in use

Answer 12

Charged
Larger
Saturates

Question 13

A _____ is a protein, that forms a poor through which a small polar molecule/ion can move through

Answer 13

Channel

Question 14

A _____ binds the solute on one side of the membrane, changes shape, and then release is the solute on the other side of the membrane

Answer 14

Transporter

Question 15

Answer 15

Question 16

Sodium and potassium transporters use ____ and active transport to move molecules against their gradient

Answer 16

ATP

Question 17

Answer 17

Question 18

There are two kinds of active transport ____ active transport, and ____ active transport

Answer 18

Primary
Secondary

Question 19

Primary active transport directly uses the energy in ____ to move substances against a concentration gradient. They are also called _____. They are both transporters and ____.

Answer 19

ATP
Pumps
Enzymes

Question 20

With ____ ____ transport, the proteins that moves the substance is the same protein that hydrolyzes the ATP.
Example: ____

Answer 20

Primary active
Sodium/potassium ATPase

Question 21

Secondary active transport ____ uses ATP by using the sodium that the primary active transporter generated.

Answer 21

Indirectly

Question 22

___ ____ transporters move molecules against a concentration gradient by using the pen, pencil energy in a sodium gradient. It is still active transport, because the movement of the substance would not occur if ____ had not hydrolyzed elsewhere in the cell.
Example:

Answer 22

Secondary active
ATP
Sodium/glucose transporter

Question 23

How is glucose being transported on the capillary side of the cell in the small intestine and proximal tubule of the kidney?

Answer 23

Facilitated diffusion
The cell uses primary active transport to generate a sodium gradient and secondary active transport to generate a glucose gradient, so that glucose can enter and travel in the blood.

Question 24

A ____ ___ secretes HCl into the stomach lumen. They exhibit _____ Na/K ATPases, moving ions against their concentrated gradient, using ATP.

Answer 24

Parietal cell
Basolateral

Question 25

Answer 25

Question 26

Inhibition of the H+/K+ ATPase in parietal cells would cause ____ acid secretion and a ____ luminal pH.

Answer 26

Less
Higher

Question 27

Answer 27

Question 28

HCO3-/Cl- exchanger is located on the ___ side of the parietal cell. HCO3- leaving the cell permits ___ to enter the cell along an electrochemical gradient

Answer 28

Basolateral
Cl-

Question 29

Small intestine:
The cells in the villi have transporters that promote absorption of ___, ___, ___.
The cells in the ____ contain transporters that promote the secretion of chlorine ions, sodium ions, and water are secreted as a result

Answer 29

Water, nutrients, and ions
Crypts

Question 30

In the small intestine typically more ____ is absorbed than secreted

Answer 30

Water

Question 31

The Na/K ATPase on the basolateral side of the cells in the villi use the chemical energy in ATP to create an ___ sodium gradient. On the luminal side, sodium is moving ____ its concentration gradient

Answer 31

Inward
With

Question 32

Answer 32

Question 33

Water moves across enterocytes in the small intestine through water channels called ____.

Answer 33

Aquaporins (AQN)

Question 34

As sodium and other molecules are transported across the cell layer, the concentration of particles in the lumen decreases as a concentration of particles in the interstitium increases. As this occurs, the opposite occurs with ____ concentration. Water in the lumen is ____ then in the interstitium period water crosses the cells layers through aqua Porins, or between the cells through the tight junction via _____

Answer 34

Water
Higher
Osmosis

Question 35

Answer 35

Question 36

Answer 36

Question 37

Answer 37

Question 38

When ____ is present, the kidneys, save water, because aquaPourin 2 is inserted in the luminal membrane

Answer 38

ADH

Question 39

When ADH is _____, the kidneys, permit water to stay in the urine, because the aquaporin 2 is internalized

Answer 39

Absent

Question 40

Answer 40

Question 41

____ is the most abundant cation in the extracellular fluid. If the kidneys save too much water, plasma sodium concentration ____ below normal, causing hyponatremia

Answer 41

Na+
decreases

Question 42

Answer 42

Question 43

Muscle contraction depends on ____ released from the sarcoplasmic reticulum

Answer 43

Calcium

Question 44

During contraction of muscles, the electrical signal from the muscle action potential is converted into it a chemical stimulus that opens a ___ channel.

Answer 44

Calcium

Question 45

Calcium ions bind to ____ within fibers to allow the whole muscle to contract and shorten

Answer 45

Myofilaments

Question 46

In order for the muscle to ___, calcium must be removed

Answer 46

Relax

Question 47

_______ generates an inward gradient for sodium

Answer 47

Na/K ATPase

Question 48

The ___ active Ca2+ ATPase in the plasma membrane removes Ca from the cell

Answer 48

Primary

Question 49

The ____ active Na/Ca2+ exchanger uses a sodium gradient to move calcium out the intracellular space

Answer 49

Secondary

Question 50

Answer 50