[11] Membrane Transport Proteins

Question 1

Define “membrane transport proteins”.

Answer 1

These are proteins embedded in cell membranes that aid in the movement of substances into and out of cells.

Question 2

What are the two main types of membrane transport proteins?

Answer 2

• Channel proteins
• Carrier proteins

Question 3

Describe the function of “channel proteins”.

Answer 3

They form pores in the cell membrane, allowing specific molecules to pass through.

Question 4

Describe the function of “carrier proteins”.

Answer 4

They bind to specific molecules, change shape, and then move these molecules across the membrane.

Question 5

What is “passive transport” in the context of membrane transport proteins?

Answer 5

It’s the movement of substances across the cell membrane without the use of energy, driven by concentration gradients.

Question 6

What is “active transport” in the context of membrane transport proteins?

Answer 6

It’s the movement of substances against a concentration gradient, which requires energy.

Question 7

Name the types of passive transport facilitated by membrane transport proteins.

Answer 7

• Simple diffusion
• Facilitated diffusion

Question 8

What is “simple diffusion”?

Answer 8

It’s the movement of small, nonpolar molecules directly across the cell membrane.

Question 9

What is “facilitated diffusion”?

Answer 9

It’s the movement of large or polar molecules across the cell membrane via transport proteins.

Question 10

Which type of transport protein is typically involved in facilitated diffusion?

Answer 10

Both channel proteins and carrier proteins can be involved.

Question 11

What is a “symporter”?

Answer 11

It’s a type of carrier protein that transports two different substances in the same direction across a cell membrane.

Question 12

What is an “antiporter”?

Answer 12

It’s a type of carrier protein that transports two different substances in opposite directions across a cell membrane.

Question 13

How does an ATP-powered pump work in active transport?

Answer 13

It uses energy from ATP to change shape and move substances against a concentration gradient.

Question 14

What is a “uniporter”?

Answer 14

It’s a type of carrier protein that transports a single substance in one direction across a cell membrane.

Question 15

Name two examples of ATP-powered pumps in human cells.

Answer 15

• Sodium-potassium pump
• Calcium pump

Question 16

What is the role of membrane transport proteins in cell communication?

Answer 16

They can act as receptors for signaling molecules, initiating a cellular response.

Question 17

Why are membrane transport proteins important for cell survival?

Answer 17

They regulate the movement of substances into and out of cells, maintaining cell homeostasis.