Cell Signalling I

Question 1

What are the types of cell signalling that can take place?

Answer 1

Contact-dependent

Juxtacrine

Paracrine

Synaptic

Endocrine

Autocrine

Question 2

What is contact-dependent signalling?

Answer 2

Signalling that requires direct membrane-membrane contact. Also known as juxtacrine signalling

Question 3

How are hormones classified by chemical properties?

Answer 3

Solubility and size. Split into 3 major groups:

Small lipophilic (eg corticoids and oestrogen)

Hydrophilic (eg polypeptides such as insulin)

Large lipophilic (eg prostaglandins)

Question 4

Define 7 steps for essential and specific information transfer:

Answer 4

Synthesis of hormone

Release

Transport (to target cell)

Detection (binding to receptor)

Transduction (moves signal from outside to inside the cell)

Target cell response

Termination of signal

Question 5

What responses can target cells have?

Answer 5

Changes in enzyme activity (very fast)

Changes in protein expression (Relatively slower with longer lasting effects)

Question 6

Can cells have different responses to the same hormone?

Answer 6

Yes, they can respond to the same stimulus but invoke a different biological response

Question 7

Can hormones cause more than one change in a cell?

Answer 7

Yes