Cell Membranes

In biological membranes, the phospholipids are arranged in a _______, with the_______.

• bilayer; fatty acids pointing toward each other
• bilayer; fatty acids facing outward
• single layer; fatty acids facing the interior of the cell
• single layer; phosphorus-containing region facing the interior of the cell

Which statement about cholesterol molecules is true?

• They help hold a membrane together.
• They alter the fluidity of the membrane.
• They attach to carbohydrates.
• They disrupt membrane function.

A protein that forms an ion channel through a membrane is most likely 

• a peripheral membrane protein
• a phospholipid
• an enzyme.
• a transmembrane protein

If a hospital patient is mistakenly given an IV of pure water instead of a saline solution that is isotonic to blood, the patient’s red blood cells will

• shrink and collapse
• release water to the plasma along its concentration gradient
• absorb water from the plasma and eventually burst
• transport equal amounts of water across the cell membrane in both directions

Tags

NGSS.HS-LS1-3

If aquaporins are injected into the membranes of epithelial cells that line blood vessels,

• the flow of Na+ through aquaporins will increase
• the intracellular concentration of K+ will increase
• the membranes will become more permeable to water
• the electrical properties of the cells will be altered

Which of the following is the driving force for simple diffusion?

• Concentration gradient
• ATP hydrolysis
• ADP hydrolysis
• Phosphorylation

Which of the following is the driving force for facilitated diffusion?

• Concentration gradient
• ATP hydrolysis
• ADP hydrolysis
• Phosphorylation

If you were designing a drug with an intracellular target, which type of transport system would you want to include in your design as the most efficient way to deliver the drug?

• Secondary active transport
• Primary active transport
• Simple diffusion
• Facilitated diffusion via a carrier protein

When cells are placed in a __________ solution they begin to swell.

• Hypertonic
• Isotonic
• Hypotonic
• Equalized

Tags

NGSS.HS-LS1-3

A HYPOTONIC solution has a ______ concentration of solute than the cell and the cell will _____ when placed into a hypotonic solution.

• lower; swell
• lower; shrink
• higher; swell
• higher; shrink