4.4: Active transport

Question 1

Active transport

Answer 1

Active transport is the movement of molecules or ions into or out of a cell from a region of lower concentration to a region of higher concentration using:

1. ATP
2. Carrier proteins

Question 2

Carrier proteins have a specific tertiary structure and will only transport what across a membrane?

Answer 2

Carrier proteins:

1. Have a specific tertiary structure
2. Will only transport particular substances across a membrane

Question 3

Active transport differs from passive forms of transport in the following ways:
1. What in the form of ATM is needed?

Answer 3

Metabolic energy in the form of ATP is needed

Question 4

Active transport differs from passive forms of transport in the following ways:

1. Metabolic energy in the form of ATP is needed.
2. Substances are moved against what?

Answer 4

Substances are moved against a concentration gradient

Question 5

Active transport differs from passive forms of transport in the following ways:

1. Metabolic energy in the form of ATP is needed.
2. Substances are moved against a concentration gradient, from a lower to a higher concentration.
3. What are involved?

Answer 5

Carrier protein molecules that act as ‘pumps’ are involved

Question 6

Active transport differs from passive forms of transport in the following ways:

1. Metabolic energy in the form of ATP is needed.
2. Substances are moved against a concentration gradient, from a lower to a higher concentration.
3. Carrier protein molecules that act as ‘pumps’ are involved.
4. The process is very what?

Answer 6

The process is very selective

Question 7

Active transport differs from passive forms of transport in the following ways:

1. Metabolic energy in the form of ATP is needed.
2. Substances are moved against a concentration gradient, from a lower to a higher concentration.
3. Carrier protein molecules that act as ‘pumps’ are involved.
4. The process is very selective, with what being transported?

Answer 7

The process is very selective, with specific substances being transported

Question 8

Different carrier proteins are involved in facilitated diffusion and active transport, but any given protein carrier is very specific about what?

Answer 8

Different carrier proteins are involved in facilitated diffusion and active transport, but any given protein carrier is very specific about:

1. What it carries
2. By which method

Question 9

Examples of active transport

Answer 9

Examples of active transport are:

1. Absorbing glucose by the small intestine and kidney tubule cells
2. Salt uptake by plant roots

Question 10

Where are pumps located?

Answer 10

Pumps are located in membranes

Question 11

Pumps are located in membranes.
Pumps are specific and transport certain substances, so different pumps transport different substances.
Increasing the concentration of the substance being transported increases the rate of transport up to a what point?

Answer 11

Increasing the concentration of the substance being transported increases the rate of transport up to a saturation point

Question 12

Pumps are located in membranes.
Pumps are specific and transport certain substances, so different pumps transport different substances.
Increasing the concentration of the substance being transported increases the rate of transport up to a saturation point, where what is reached?

Answer 12

Increasing the concentration of the substance being transported increases the rate of transport up to a saturation point, where the optimum rate is reached

Question 13

Carrier proteins in active transport combine with what?

Answer 13

Carrier proteins in active transport combine with the substance to be moved

Question 14

Carrier proteins in active transport combine with the substance to be moved.
The carrier protein does what, which transports the substance to the other side of the membrane?

Answer 14

The carrier protein changes its shape, which transports the substance to the other side of the membrane

Question 15

Carrier proteins in active transport combine with the substance to be moved.
The carrier protein changes its shape, which transports the substance to the other side of the membrane.
What is used to change the carrier molecule back to its original shape?

Answer 15

ATP is used to change the carrier molecule back to its original shape

Question 16

Exocytosis

Answer 16

Exocytosis is when cells secrete a substance for use elsewhere

Question 17

Endocytosis

Answer 17

Endocytosis is phagocytosis

Question 18

Pinocytosis is how virtually all eukaryotic cells do what?

Answer 18

Pinocytosis is how virtually all eukaryotic cells continually form small enclosing vesicles of the surrounding fluid