Biology Concepts

Front

Diffusion

Back

Movement of molecules from high concentrations to low concentrations. Requires no energy (passive transport).

Front

Active Transport

Back

Requires the use of energy, usually moving molecules from a low concentration to a high concentration (against the flow of diffusion).

Front

Osmosis

Back

The diffusion of water into or out of the cell. If water diffuses into the cell, the cell swells and may burst. If it loses water, it will shrivel up.

Front

Stimulus

Back

A change in the environment that you respond to.

Front

Neuron

Back

A nerve cell.

Front

Impulse

Back

The electrical signal carried by the nerves. Neurotransmitters are chemicals that help carry the impulse.

Front

Hormone

Back

A chemical signal secreted by different glands in the body. Examples include insulin, adrenaline, testosterone, and estrogen.

Front

Receptor Molecules

Back

Proteins on the surface of the cell membrane that receive signals from the nervous and endocrine system.

Front

Common Elements in Living Things

Back

Carbon, Hydrogen, Oxygen, and Nitrogen (CHON).

Front

Organic Compounds

Back

Have Carbon AND Hydrogen. Organic molecules are larger than inorganic molecules.