Cell Biology

Front 1

4 Functions of Membrane Proteins

Back 1

TRANSPORT - regulation of transport of substances into and out of the cell through selective and differential permeability

SIGNALLING - Detection of chemical messages arriving at the surface of the cell via ligands binding to receptors

INTERCELLULAR INTERACTIONS BETWEEN ADJACENT CELLS- Linking of adjacent cells by membrane junctions

IONIC & HYDROSTATIC BALANCE- Generation and maintenance of the resting membrane potential

Front 2

Define Passive Transport Across the Cell Membrane

Back 2

Doesn't require ATP

Mediated by Gradients

Movement will continue until there is equalization and the gradient no longer exists

Front 3

Name three types of gradient that exist

Back 3

Electrical Gradient

opposite charges attract

Chemical or Concentration Gradient

Movement from high concentration to low

Osmotic Gradient

Water moves to an area of high osmolarity

Front 4

What properties must a substance have to pass through the cell membrane

Back 4

Must be

Small

Lipid soluble

Front 5

Examples of molecules that pass through the cell membrane by simple diffusion.

Back 5

Oxygen

Carbon dioxide

Steroids

Alcohol

Front 6

Examples of molecules that pass through the cell membrane facilitated by channels

Back 6

Ions

Water (channels called aquaporins)

Front 7

Examples of molecules that pass through the cell membrane facilitated by transporters or carrier proteins

Back 7

Larger solutes

Glucose (GLUt transporters)

Amino Acids

Front 8

Describe properties of ion channels

Back 8

Transport ions (Na+, K+, Cl-, Ca++).

Movement still driven by gradients

Can be selective and differential

Can be opened and closed by:

Chemicals (ligands) binding to receptors - chemically or ligand gated channels

Changes in electrical charge detected by voltage sensors on the channel - voltage gated channels

Front 9

Define Active Transport

Back 9

Pumps use energy to move substances against a chemical geadient.

Front 10

Define ATPase

Back 10