Cells - Transport across cell membranes - 3.2.3.4 - Active Transport

Question 1

The movement of molecules or ions AGAINST a concentration gradient using ATP and carrier proteins is describing…

Answer 1

Active transport

Question 2

Difference between active transport and facilitated diffusion

Answer 2

1. active transport uses ATP
2. Active transport uses only carriers (FD uses channels and carriers)
3. Active transport moves molecules against their concentration gradient

Question 3

Differences between active transport and osmosis

Answer 3

1. Active transport moves solutes or ions osmosis water moves
2. Active transport uses a carrier to transport a molecule across the plasma membrane, osmosis water moves through the membrane directly

Question 4

In active transport what does the molecule that is moving bind to on the carrier molecule?

Answer 4

A receptor/binding site

Question 5

After the molecule has bound to the receptor on the carrier (in active transport), what happens next?

Answer 5

ATP binds to the carrier on the opposite side, it splits into ADP and Phosphate (P) (releasing energy) causing the carrier to change shape, allowing the entry of the molecule.

Question 6

Why do some cells like root hair cells possess so many mitochondria?

Answer 6

Because they transport mineral ions against a concentration gradient. This requires energy

Question 7

What is unique about the carrier proteins used in active transport?

Answer 7

they have a specific tertiary structure

Question 8

Where is active transport used in humans?

Answer 8

Gut/Small intestine - absorption of glucose

Question 9

How is low levels of glucose absorbed in the small intestine?

Answer 9

Using Na co transporter - ATP used indirectly

Question 10

Which form of cell transport requires energy?

Answer 10

active transport

Question 11

Which type of protein are involved in active transport?

Answer 11

carrier proteins

Question 12

rate of active transport is affected by..

Answer 12

1. speed of carrier molecules
2. number of carrier molecules
3. rate of respiration - ATP availability

Question 13

How does more carrier molecules affect active transport?

Answer 13

increases the rate

Question 14

How does an inhibitor of respiration affect active transport?

Answer 14

Less or NO ATP produced to rate of active transport reduced

Question 15

Where does the energy for active transport come from?

Answer 15

Hydrolysis of ATP (produced in respiration)