Cell Communication

Question 1

Examples of transmembrane receptors

Answer 1

GPCRs, Ion channels, Enzyme linked, Cytoplasmic/nuclear

Question 2

Stages of cell signalling

Answer 2

Activation, Transducer, Amplifier, Messenger, Sesor/effector (responses)

Question 3

GPCRs

Answer 3

7 a-helix transmembrane regions, Interact with G-proteins which have 3 subunits (a, b and y), Convert GTP to GDP

Question 4

Ion channels

Answer 4

Can be gated or just channels, 5 transmembrane subunits, control electrostatic potential across the membrane

Question 5

Enzyme receptors

Answer 5

Extracellular ligand binding domain, single helical transmembrane region, internal kinase activity

Question 6

Cytoplasmic/nuclear receptors

Answer 6

Alter gene transcription directly, Oestrogen, thyroid, retinoic acid and steroid hormone receptors

Question 7

Sulbutamol is a beta-2 agonost. What does that do?

Answer 7

Dilates airways. Used for asthma treatments

Question 8

Define Gap Junction

Answer 8

Allows the passage of small water-soluble ions and molecules between adjacent cells. (2-4nm pore)

Question 9

Define Tight Junction

Answer 9

Seals neighbouring cells together with an epithelial sheet to prevent leakages.

Question 10

Define Adherens Junction

Answer 10

Joins actin bundles of adjacent cells

Question 11

Define Desmosome

Answer 11

Joins the intermediate filaments of adjacent cells

Question 12

Define Hemidesmosome

Answer 12

Anchors intermediate filaments to the basal lamina

Question 13

Define Autocrine communication

Answer 13

A cell signalling itself. e.g. Il-1

Question 14

Define Endocrine communication

Answer 14

Hormonal, long distance signalling. e.g. Insulin

Question 15

Define Neurocrine signalling

Answer 15

Signals originating from a nerve. e.g. norepinephrine

Question 16

Define Paracrine signalling

Answer 16

Local, cell-to-cell signalling. e.g. Thromboxane

Question 17

Define Juxtacrine signalling

Answer 17

Signalling which require cell-to-cell contact. e.g. leukocytes interacting