1.3.2 ion transport pumps and generation of ion gradients

Question 1

what needs to combine to form the electrochemical gradient that determines the transport of the solute carrying a net charge

Answer 1

the concentration gradient and the electrical potential difference

Question 2

what does the combination of the concentration gradient and electrical potential difference of a solute carrying a net charge form

Answer 2

the electrochemical gradient that determines the transport of the solute

Question 3

what is membrane potential

Answer 3

the electrical potential difference

Question 4

when is membrane potential created

Answer 4

when there is a difference in electrical charge on the two sides of the membrane

Question 5

what do ion pumps use to establish and maintain ion gradients

Answer 5

the energy form the hydrolysis of ATP

Question 6

what does the use of energy from the hydrolysis of ATP by ion pumps do

Answer 6

it establishes and maintains ion gradients

Question 7

what is an example of an ion pump

Answer 7

the sodium potassium pump

Question 8

what does the sodium potassium pump do

Answer 8

it transports ions against a steep concentration gradient using energy directly from ATP hydrolysis

Question 9

what does the sodium potassium pump actively transport into the cell

Answer 9

potassium ions

Question 10

what does the sodium potassium pump actively transport out of the cell

Answer 10

sodium ions

Question 11

what is the ion transportation for the sodium potassium pump relative to the hydrolysation of a single ATP

Answer 11

• three sodium ions
• two potassium ions

Question 12

what does the transport of 3 sodium ions and 2 potassium ions establish

Answer 12

both concentration gradients of the ions, and the electrical gradient

Question 13

describe the process of the sodium potassium pump’s active transport

Answer 13

• the pump has high affinity for sodium ions inside the cell
• binding occurs
• phosphorylation by ATP
• conformation changes
• affinity for sodium ions decreases
• sodium ions released outside of the cell
• potassium ions bind outside the cell
• dephosphorylation
• conformation changes
• potassium ions taken into the cell
• affinity returns to start

Question 14

where is the sodium potassium pump found

Answer 14

in most animal cells

Question 15

what does the sodium potassium pump account for in most animal cells

Answer 15

a high proportion of the basal metabolic rate in many organisms

Question 16

what does the sodium gradient in the small intestine generated by the sodium potassium pump drive

Answer 16

the active transport of glucose

Question 17

what does the sodium potassium pump generate in intestinal epithelial cells

Answer 17

a sodium ion gradient across the plasma membrane

Question 18

what is responsible for the glucose symport. and what does it transport.

Answer 18

the glucose transporter transports sodium ions and glucose at the same time and in the same direction

Question 19

how does glucose get into a cell in the intestine, against its concentration gradient.

Answer 19

• the glucose transporter transports sodium ions and glucose at the same time and in the same direction.
• the sodium ions enter a cell down their concentration gradient
• the simultaneous transport of glucose alongside the sodium ions means that the glucose is pumped into the cell against its concentration gradient