Cell Membrane + Transport

Front

What is the cell membrane?

Back

The cell membrane is a biological membrane that separates and protects the interior of all cells from the outside environment. It is composed of a double layer of phospholipids with embedded proteins.

Front

What does it mean for a membrane to be semi-permeable?

Back

A semi-permeable membrane allows some substances to pass through while blocking others, enabling selective transport of materials.

Front

Define active transport.

Back

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

Front

Define passive transport.

Back

Passive transport is the movement of substances across a cell membrane without the use of energy, following the concentration gradient.

Front

What is osmosis?

Back

Osmosis is the movement of water molecules from an area of high water concentration to an area of low water concentration through a semi-permeable membrane.

Front

What is diffusion?

Back

Diffusion is the process by which molecules spread from an area of high concentration to an area of low concentration until equilibrium is reached.

Front

What is facilitated diffusion?

Back

Facilitated diffusion is the process of passive transport of molecules across a cell membrane via specific transmembrane integral proteins.

Front

What is endocytosis?

Back

Endocytosis is the process by which cells internalize substances by engulfing them in a membrane-bound vesicle.

Front

What is exocytosis?

Back

Exocytosis is the process by which cells expel materials in vesicles that fuse with the cell membrane, releasing their contents outside the cell.

Front

What role do proteins play in the cell membrane?

Back

Proteins in the cell membrane serve various functions, including transport, acting as channels or carriers, and facilitating communication between the cell and its environment.