Cell Signalling Pathways

Question 1

Cell signalling definition

Answer 1

Process by which a cell responds to substances outside the cell through signalling molecules found on the surface and inside the cell

Question 2

Why is cell signalling important

Answer 2

For cell growth, secretion, motility and metabolism

Question 3

Process of cell signalling

Answer 3

Ligand binds to its receptors
Alters the shape or activity of the receptor triggering a change inside the cell
Relayed through a chain of chemical messengers

Question 4

Forms of signalling

Answer 4

Paracrine
Autocrine
Endocrine
Signalling through cell-cell contact

Question 5

Paracrine signalling

Answer 5

Cells close together communicate through release of chemical messengers
E.g synaptic signalling

Question 6

Autocrine signalling

Answer 6

Cell signals to itself releasing a ligand that binds to receptors on its own surface

Question 7

Endocrine signalling

Answer 7

Signals produced by specialised cells and released into bloodstream which carries them to target cells in distant parts of the body
Endocrine glands release hormones

Question 8

Signalling through cell cell contact

Answer 8

Water filled channels allow small signalling molecules called intracellulsr mediators to diffuse between the two cells

Two cells may bind to one another because they carry complementary proteins on their surfaces
Proteins bind to one another causing a change in the shape of the protein transmitting a signal