4.1%2C4.3-4

Energy

The ability to do work or to move matter.

Kinetic energy

The energy of motion or movement.

Potential energy

Stored energy that is available to do work.

Chemical bonds

Forms of potential energy in molecules like glucose.

First law of thermodynamics

Energy is never created or destroyed, only transformed.

ATP (Adenosine Triphosphate)

The primary energy carrier in cells.

Entropy

A measure of disorder in a system; it tends to increase over time.

Homeostasis

The mechanisms that maintain a stable internal environment within cells.

Simple diffusion

A passive transport process where molecules move down their concentration gradient without energy.

Facilitated diffusion

A passive transport process that requires membrane proteins to help molecules cross the membrane.

Active transport

The process where substances are moved against their concentration gradient using energy.

Sodium-Potassium pump

A transport protein that moves sodium ions out of and potassium ions into the cell, requiring energy.

Endocytosis

The process by which cells engulf substances to bring them into the cell using vesicles.

Exocytosis

The process by which cells secrete large molecules, such as proteins, out of the cell using vesicles.

Enzymes

Proteins that act as catalysts to speed up biochemical reactions without being consumed.

Activation energy

The energy required to start a chemical reaction.

Enzyme inhibitors

Substances that decrease enzyme activity by blocking substrates from binding to the active site.