Membranes and Transport

Front

What is passive transport?

Back

Passive transport is the movement of substances across a cell membrane without the use of energy (ATP). It occurs along the concentration gradient.

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What are the types of passive transport?

Back

The types of passive transport include simple diffusion, facilitated diffusion, and osmosis.

Front

What is active transport?

Back

Active transport is the movement of substances across a cell membrane using energy (ATP) against the concentration gradient.

Front

What is a phospholipid?

Back

A phospholipid is a molecule composed of a phosphate group, a glycerol backbone, and two fatty acid tails, forming the fundamental building block of cell membranes.

Front

What role does cholesterol play in the cell membrane?

Back

Cholesterol strengthens and stabilizes the cell membrane, making it less permeable to very small water-soluble molecules that might otherwise pass freely through.

Front

What is endocytosis?

Back

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

Front

What is the difference between passive and active transport?

Back

The main difference is that passive transport does not require energy and moves substances along the concentration gradient, while active transport requires energy to move substances against the concentration gradient.

Front

What is facilitated diffusion?

Back

Facilitated diffusion is a type of passive transport that uses transport proteins to help move substances across the cell membrane.

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What is osmosis?

Back

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

Front

What are transport proteins?

Back

Transport proteins are integral membrane proteins that assist in the movement of ions and molecules across the cell membrane.