Lecture 1

Question 1

What is cell signalling

Answer 1

Cell signalling is how cells and tissues communicate with each other

Question 2

Endocrine

Answer 2

Act upon a distant group several metres away, in an animal the blood usually carries signalling molecules to the site of action

Question 3

Paracrine

Answer 3

The target cell is a neighbour eg neurotransmitters

Question 4

Autocrine

Answer 4

The cell releases and responds to it own signalling substance eg IGF1 and tumour cells

Question 5

What are the steps involved in cell to cell communication

Answer 5

Synthesis of signalling molecule, release, transport, detection via receptors, change in target cell, removal and termination

Question 6

What are the three categories of signalling molecules

Answer 6

1 small lipophillic hydrophobic molecules which bind to intracellular receptors eg steroids
2 hydrophilic molecules which bind to cell surface receptors eg insulin
3 other lipophilic molecules eg Eicosanoids

Question 7

What are receptors

Answer 7

Proteins present in the plasma membrane, cytosol or nucleus and they have a high affinity binding site to a ligand

Question 8

Examples of intracellular receptors

Answer 8

Steroids, thyroxine and Retonic acid

Question 9

Cell surface receptors

Answer 9

Bind to hydrophilic ligands and activation leads to phosphorylation eg cAMP

Question 10

Examples of secondary messengers

Answer 10

Ca+, cAMP, IP3, DAG