A&P 12 - Unit 1

The maintenance of body systems in a state of balance and equilibrium.

Homeostasis

The principle stating all organisms are made of cells and that cells are the basic unit of life.

Cell Theory

A two-layered sheet of lipids with hydrophilic heads and hydrophobic tails that surrounds all cells.

Phospholipid Bilayer

Small structures within a cell that have a specific structure and function.

Organelle

The dark granule in the center of the cell that stores genetic info and directs cell activities.

Nucleus

Rod-shaped structures that act as the powerhouse of the cell by generating ATP.

Mitochondria

Small structures made of rRNA that serve as the site of protein synthesis.

Ribosomes

A system of membranous channels studded with ribosomes used to synthesize and process proteins.

Rough Endoplasmic Reticulum

A stack of curved sacs that collects, sorts, and packages proteins and lipids in the cell.

Golgi Apparatus

Vesicles containing hydrolytic enzymes used for recycling old cell parts or digesting invaders.

Lysosome

A property of the cell membrane where it only lets select materials in and out.

Selectively Permeable

The net movement of a substance down its concentration gradient from high to low concentration.

Diffusion

The passive movement of water molecules across a semi-permeable membrane.

Osmosis

Movement of molecules down a concentration gradient using a protein channel or carrier.

Facilitated Diffusion

The movement of molecules against their concentration gradient requiring the input of ATP energy.

Active Transport

The process of taking large substances into the cell by engulfing them with the cell membrane.

Endocytosis

The process by which the cell releases important materials or waste products out of the cell.

Exocytosis

A comparison that determines cell efficiency and limits how large a cell can grow.

Surface Area to Volume Ratio

The chemical energy currency used to power cellular processes like active transport.

ATP

A chemical that takes up excess hydrogen ions to help keep pH constant.

Buffer