bio chp 7 (no slides)

Receptor

A protein molecule that receives chemical signals from outside a cell.

Osmosis

The movement of water across a semipermeable membrane from an area of lower solute concentration to an area of higher solute concentration.

Diffusion

The process of spread of particles from areas of high concentration to areas of low concentration.

Concentration

The abundance of a constituent divided by the total volume of a mixture.

Cell

The basic structural, functional, and biological unit of all known living organisms.

Immune system

The complex group of cells and proteins that defend the body against infection.

Sugar and salt effect on cells

The intake of sugar and salt can create osmotic pressure that leads to the diffusion of water into cells.