Blank Quiz

1. Which of the following is a characteristic of facilitated diffusion?

• a) Requires energy in the form of ATP
• b) Moves substances against their concentration gradient
• c) Involves transport proteins
• d) Moves molecules at the same rate regardless of concentration

2. Which of the following best describes the function of a channel protein in a cell membrane?

• a) Transports molecules against their concentration gradient
• b) Forms a pore through which specific molecules or ions can pass
• c) Binds to molecules and changes shape to shuttle them across the membrane
• d) Hydrolyzes ATP to provide energy for transport

Which statement is true regarding facilitated diffusion?

• a) It requires energy input from the cell.
• b) It can transport molecules against their concentration gradient.
• c) It requires a transport protein to move substances across the membrane.
• d) It is slower than simple diffusion because it involves transport proteins.

Ion channels that open in response to a change in membrane potential are called:

• a) Ligand-gated channels
• b) Voltage-gated channels
• c) Mechanically-gated channels
• d) Aquaporins

Aquaporins are specialized for the transport of which molecule across the cell membrane?

• a) Glucose
• b) Ions
• c) Water
• d) Amino acids

Ionophores are often used in research to:

• a) Study water transport across membranes
• b) Induce ion imbalance in cells
• c) Block aquaporin channels
• d) Enhance protein synthesis

Ionophores are molecules that:

• a) Bind to and transport ions across the cell membrane
• b) Block ion channels in the membrane
• c) Act as receptors for hormones
• d) Facilitate the diffusion of water across the membrane

The antibiotic valinomycin is an example of:

• a) An aquaporin
• b) A channel protein
• c) An ionophore
• d) A receptor protein

Which of the following ionophores specifically facilitates the transport of potassium ions (K+)?

• a) Gramicidin
• b) Monensin
• c) Valinomycin
• d) A23187