Cell Membranes & Transport

Front

What is the function of a vesicle in endocytosis and exocytosis?

Back

A vesicle is a small membrane-bound sac that transports materials into (endocytosis) or out of (exocytosis) a cell.

Front

What role does cholesterol play in cell membranes?

Back

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

Front

What are the two forms of active transport?

Back

The two forms of active transport are primary active transport, which uses ATP directly, and secondary active transport, which uses the energy from the electrochemical gradient.

Front

How does salt intake affect cell hydration?

Back

Eating salty foods can draw water out of cells, leading to dehydration of those cells, which is why you feel thirsty after consuming salt.

Front

What is osmosis?

Back

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

Front

What is the difference between passive and active transport?

Back

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

Front

What is a selectively permeable membrane?

Back

A selectively permeable membrane allows certain molecules or ions to pass through it while blocking others, maintaining the internal environment of the cell.

Front

What is diffusion?

Back

Diffusion is the process by which molecules spread from areas of high concentration to areas of low concentration.

Front

What is the significance of the fluid mosaic model?

Back

The fluid mosaic model describes the structure of cell membranes, emphasizing that they are flexible and composed of various proteins that float in or on the fluid lipid bilayer.

Front

What happens to a cell in a hypertonic solution?

Back

In a hypertonic solution, water moves out of the cell, causing it to shrink or crenate.