Cell Membrane and Transport

Front

What is a 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 primarily composed of a double layer of phospholipids with embedded proteins.

Front

What are phospholipids?

Back

Phospholipids are a class of lipids that are a major component of all cell membranes. They consist of two fatty acids, a glycerol unit, and a phosphate group, forming a bilayer that is hydrophobic on the inside and hydrophilic on the outside.

Front

What is 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 diffusion?

Back

Diffusion is the process by which molecules spread from areas of high concentration to areas of low concentration until they are evenly distributed.

Front

What is endocytosis?

Back

Endocytosis is the process by which cells internalize substances from their external environment 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 is isotonic solution?

Back

An isotonic solution is one where the concentration of solutes is equal inside and outside the cell, resulting in no net movement of water.

Front

What is hypotonic solution?

Back

A hypotonic solution has a lower concentration of solutes compared to the inside of the cell, causing water to enter the cell and potentially leading to cell swelling or bursting.

Front

What is hypertonic solution?

Back

A hypertonic solution has a higher concentration of solutes compared to the inside of the cell, causing water to leave the cell and leading to cell shrinkage.

Front

What happens to red blood cells in a hypertonic solution?

Back

Red blood cells placed in a hypertonic solution will lose water and shrink, a process known as crenation.