8 - Intro to Cell Signalling

Question 1

Control of gene expression (central dogma of molecular biology

Answer 1

DNA replication -> transcription -> translation -> protein -> cell responses

Question 2

When does post-translational modification take place?

Answer 2

After translation and before cell responses

Question 3

What can occur after the production of a protein?

Answer 3

• cell responses
• post translational modification (can lead to degradation or cell responses
• degradation

Question 4

When does control of gene expression by hormones occur?

Answer 4

Can occur during:
- transcription
- translation
- degradation
- post-translational modification

Question 5

What kinds of biology involve cell signalling?

Answer 5

• cancer biology (oncogenes)
• developmental biology (growth and differentiation pathways)
• endocrinology (hormone response pathways)
• immunology (immune activation pathways)
• neurobiology (neuronal signalling)

Question 6

Features of cell signalling

Answer 6

1. enables transmission from outside of cell to nucleus
2. fast ON and OFF (seconds to minutes)
3. transient changes (minutes to hours)
4. spatial.directional responses and organisation
5. energetically cheap (no protein synthesis)

Question 7

Features of gene expression

Answer 7

1. slow ON and OFF (minutes to hours)
2. stables changes (hours to years)
3. limited spatial responses
4. energetically costly (transcription and translation)

Question 8

Examples of cell signalling inputs

Answer 8

• environmental stresses
• signals from other cells
• extracellular matrix
• nutrient signals
• internal states (homeostasis, cell cycle)

Question 9

Examples of signalling outputs

Answer 9

• gene expression
• morphological changes
• production/secretion
• growth/division
• senescence/death

Question 10

Cell signalling outcomes

Answer 10

1. binding/dissociation
2. conformational change
3. post-translational modification
4. localisation

Question 11

Currencies of cell signalling

Answer 11

• protein-protein interactions
• confirmation
• enzymatic activity
• post-translational modification
• sub cellular localisation; concentration
• small-molecule signalling mediators