23 Plasma Membrane and Cell Transport

Front

What is facilitated diffusion?

Back

Facilitated diffusion is a passive transport process that requires transport proteins to help move molecules across the plasma membrane along a concentration gradient.

Front

What is simple diffusion?

Back

Simple diffusion is the movement of molecules from an area of high concentration to an area of low concentration without the need for transport proteins or energy.

Front

What is active transport?

Back

Active transport is the process of moving molecules against their concentration gradient, from low to high concentration, which requires energy (ATP).

Front

What are the two main components of the plasma membrane?

Back

The two main components of the plasma membrane are phospholipids and proteins.

Front

What is osmosis?

Back

Osmosis is the movement of water molecules across a selectively permeable membrane from an area of low solute concentration to an area of high solute concentration.

Front

What is the difference between passive and active transport?

Back

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

Front

What role do transport proteins play in facilitated diffusion?

Back

Transport proteins assist in the movement of specific molecules across the plasma membrane that cannot easily pass through the lipid bilayer.

Front

What is a concentration gradient?

Back

A concentration gradient is the difference in the concentration of a substance between two areas, which drives the movement of molecules during diffusion.

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 a selectively permeable membrane?

Back

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