Membrane structure, protein channels and bulk transport

Question 1

Is this passive or active transport: a white blood cell engulfing a bacterium (endocytosis)?

• A. passive (no ATP needed)
• B. active (uses ATP)

Question 2

Membranes: which statement is true?

• A. Exocytosis releases substances from a cell in vesicles.
• B. Phospholipid tails are attracted to water.
• C. Facilitated diffusion moves substances against their gradient.
• D. Large proteins pass through the membrane by simple diffusion.

Question 3

Cystic fibrosis is caused by a faulty chloride ion channel protein. What does this show?

• A. Phospholipids are made of chloride
• B. Membrane proteins are vital for moving specific ions across membranes
• C. Channel proteins carry oxygen
• D. Ions cross membranes without help

Question 4

Is this passive or active transport: a white blood cell engulfing a bacterium (endocytosis)?

• A. passive (no ATP needed)
• B. active (uses ATP)

Question 5

Membranes: which statement is true?

• A. Large proteins pass through the membrane by simple diffusion.
• B. Phospholipid tails are attracted to water.
• C. Facilitated diffusion uses carrier or channel proteins but no ATP.
• D. Facilitated diffusion moves substances against their gradient.

Question 6

Why is the cell membrane described as a "fluid mosaic"?

• A. It is made of liquid water
• B. Its proteins never move
• C. Phospholipids move freely and proteins are scattered through them like tiles
• D. It is a rigid wall of cellulose

Question 7

Is this passive or active transport: the sodium–potassium pump?

• A. passive (no ATP needed)
• B. active (uses ATP)

Question 8

Membranes: which statement is true?

• A. Phospholipid tails are attracted to water.
• B. Facilitated diffusion uses carrier or channel proteins but no ATP.
• C. Facilitated diffusion moves substances against their gradient.
• D. Large proteins pass through the membrane by simple diffusion.

Question 9

Cystic fibrosis is caused by a faulty chloride ion channel protein. What does this show?

• A. Membrane proteins are vital for moving specific ions across membranes
• B. Channel proteins carry oxygen
• C. Phospholipids are made of chloride
• D. Ions cross membranes without help

Question 10

Is this passive or active transport: simple diffusion of oxygen through the phospholipid bilayer?

• A. passive (no ATP needed)
• B. active (uses ATP)

Question 11

Membranes: which statement is true?

• A. Facilitated diffusion moves substances against their gradient.
• B. Phospholipid tails are attracted to water.
• C. Large proteins pass through the membrane by simple diffusion.
• D. The sodium–potassium pump uses ATP.

Question 12

Why can oxygen cross the membrane easily but glucose needs a protein?

• A. Glucose is a gas
• B. Glucose dissolves in fat
• C. Oxygen is small and non-polar; glucose is larger and polar
• D. Oxygen is too big for proteins

Question 13

Is this passive or active transport: a white blood cell engulfing a bacterium (endocytosis)?

• A. passive (no ATP needed)
• B. active (uses ATP)

Question 14

Membranes: which statement is true?

• A. Large proteins pass through the membrane by simple diffusion.
• B. Facilitated diffusion uses carrier or channel proteins but no ATP.
• C. Facilitated diffusion moves substances against their gradient.
• D. Phospholipid tails are attracted to water.

Question 15

Why is the cell membrane described as a "fluid mosaic"?

• A. It is a rigid wall of cellulose
• B. Its proteins never move
• C. Phospholipids move freely and proteins are scattered through them like tiles
• D. It is made of liquid water

Question 16

Is this passive or active transport: osmosis through aquaporin channels?

• A. passive (no ATP needed)
• B. active (uses ATP)