Cell Membrane- controls what enters and leaves cell.

Fluid Mosaic Model

describes the arrangement of the molecules that make up a cell membrane.

Concentration Gradient

difference in the amount of a concentration from one location to another.

Simple Diffusion

movement of everything but water from high to low concentration easily without help.

Facilitated Diffusion

movement of everything but water with the help of transport proteins (large molecules like sugar move this way).

Osmosis

movement of water from high to low concentration

Hypotonic

movement of water in cell because the solution inside the cell has higher solutes than outside.

Hypertonic

movement of water out of cell because the solution outside the cell has more solutes than inside

Cell Membrane

Controls what enters and leaves the cell

Receptor

a protein that detects a signal molecule to allow things to move in and out of cell.

Phospholipids

a type of fat that is made of a phosphate group, a glycerol and two fatty acid chains.

Selective Permeability

means it allows some, but not all materials to pass through.

Active transport

the type of transport that moves from a low to a high concentration and requires energy.

Passive Transport

type of transport with movement of molecules from high to low concentration without energy.

Isotonic

water is balanced in/out of cell because the solute concentration is also balanced.

Endocytosis

when a cell consumes food/fluid (type of active transport).

Exocytosis

when a cell releases waste/proteins (active transport).