LEC03

Question 1

The two types of cell-cell communication.

Answer 1

Local and long distance.

Question 2

The two subcategories of local cell-cell communication and what they do?

Answer 2

1. Paracrine signalling
   - Signalling cell acts on target cells by secreting molecules of local regulators.
2. Synaptic signalling
   - Neurotransmitters diffuse across synapse.

Question 3

Subcategory of long distance cell-cell communication and what it does?

Answer 3

Endocrine (hormonal) signalling
- Endocrine cells secrete hormones.

Question 4

List the three stages of cell signalling?

Answer 4

1. Reception
2. Transduction
3. Response

Question 5

Explain the three stages of cell signalling?

Answer 5

1. Reception
   - Receives information/stimuli from signalling molecule
2. Transduction
   - Alters/converts and relays message along the cells.
3. Response
   - A cellular response is seen.

Question 6

What do hormones/ligands/agonists do?

Answer 6

Bind to receptors and carry out various different actions.

Question 7

List the three membrane receptor families.

Answer 7

1. Ion channel receptors
2. G-protein coupled receptors
3. Receptor tyrosine kinases

Question 8

What do the three membrane receptor families do?

Answer 8

1. Ion channel receptors
   - Channel is opened (usually by a ligand) to allow ions to pass through for faster neurotransmission.
2. G-protein coupled receptors
   - They receive extracellular signals which prompt various bodily functions. Activated by various stimuli; light, ions, odorants, hormones, proteins, etc.
3. Receptor tyrosine kinases
   - Communicate and control various cellular responses, but most commonly, growth and motility.

Question 9

Protein Phosphorylation

Answer 9

Addition of phosphates to specific amino acid residues on proteins, leading to cellular responses.

Question 10

Steroid Receptors

Answer 10

Functions both as signal transducers and transcription factors. Important for gene expression.