AP Biology-Cells

Front

What is a peripheral protein?

Back

A peripheral protein is a protein that is attached to the exterior or interior surfaces of a cell membrane but does not penetrate the membrane itself.

Front

What does it mean that plasma membranes are selectively permeable?

Back

It means that the membrane regulates the passage of materials in and out of the cell, allowing some substances to pass while blocking others.

Front

What process do white blood cells use to engulf bacteria?

Back

Phagocytosis is the process by which white blood cells engulf and digest bacteria.

Front

Why are cells small?

Back

Cells are small to maximize their surface area-to-volume ratio, which is essential for efficient nutrient uptake and waste removal.

Front

What happens to an animal cell in a hypertonic solution?

Back

An animal cell placed in a hypertonic solution will shrink, as water moves out of the cell to balance the solute concentration.

Front

Define osmosis.

Back

Osmosis is the movement of water molecules through a selectively permeable membrane from an area of lower solute concentration to an area of higher solute concentration.

Front

What is the function of cholesterol in the plasma membrane?

Back

Cholesterol helps to stabilize the fluidity of the plasma membrane, making it less permeable to very small water-soluble molecules that might otherwise pass freely through.

Front

What is the difference between active and passive transport?

Back

Active transport requires energy to move substances against their concentration gradient, while passive transport does not require energy and moves substances down their concentration gradient.

Front

What is the role of the cell membrane?

Back

The cell membrane protects the cell, provides structure, and regulates the movement of substances in and out of the cell.

Front

What is endocytosis?

Back

Endocytosis is the process by which cells internalize substances from their external environment by engulfing them in a membrane.