C2 Interaction and Interdependence : Cells

Question 1

ligand

Answer 1

Ion or molecule that binds to a protein receptor.

Question 2

signal transduction

Answer 2

The process by which a chemical or physical signal is transmitted through a cell as a series of molecular events, most commonly protein phosphorylation catalysed by protein kinases, which ultimately results in a cellular response.

Question 3

quorum sensing

Answer 3

The regulation of gene expression in response to fluctuations in cell-population density.

Question 4

lux operon

Answer 4

Present in bioluminescent microorganisms and regulates the production of luminescent proteins.

Question 5

cytokines

Answer 5

A class of chemical signalling molecules consisting of small proteins and peptides.

Question 6

3 types of hormones

Answer 6

• amines derived from amino acids eg. melatonin
• peptide derived from small proteins eg. insulin
• steroid derived from cholesterol eg. oestradiol

Question 7

action potential

Answer 7

A rapid rise (depolarisation) and fall (repolarisation) of the membrane electrical potential caused by the opening and closing of gates through the cell membrane.

Question 8

autocrine signalling

Answer 8

A form of signalling in which the cells release chemical signals (hormones or chemical messengers) that bind to autocrine receptors on the same cell.

Question 9

paracrine signalling

Answer 9

A form of signalling in which the released chemical signals affect the target cells at very close proximity.

Question 10

endocrine signalling

Answer 10

A form of signalling in which the released chemical signals (hormones) are carried by blood over a long distance in order to cause an effect in the target cells.

Question 11

juxtacrine signalling

Answer 11

Type of cell-cell signalling that requires two cells to be in close contact.

Question 12

gap junctions

Answer 12

A type of cell junction wherein adjacent cells are linked together by intracellular channels.