Basics of cell signalling

Question 1

What is signal transduction

Answer 1

• When a cell responds to, adapts to change in its environment
• An external stimul is converted to a response within the cell

Question 2

Function of gap and tight junctions

Answer 2

• Tight junctions seal neighbouring cells together and prevent leakage
• Gap junction allow passage of small water soluble ions and molecules

Question 3

What is cell-cell recognition

Answer 3

• Cell communication by interactions on their surface
• Such as glycoproteins and lipids

Question 4

What is paracrine signalling

Answer 4

• Signal molecules are produced, they then diffuse until they reach an appropriate receptor

Question 5

What is synaptic signalling

Answer 5

• Occurs at synapse via AP

Question 6

What is autocrine signalling

Answer 6

• Autocrine signaling is a form of cell signaling in which a cell secretes a hormone or chemical messenger that binds to autocrine receptors on that same cell, leading to changes in the cell.

Question 7

What is endocrine signalling

Answer 7

Hormone made by an organ , then transported via the blood stream via a target cell

Question 8

Name the three type of molecular switches that occur as a result of signal transduction

Answer 8

1. G proteins -
2. Phosphorylation by kinase
3. Dephosphorylation by phosphates

Question 9

Describe the three steps of signal transduction

Answer 9

1. Ligand binds to protein receptor
2. Transduction - converts extrenal signal into a secondary internal one, also may amplify
3. Response - Transduced signal finally triggers a specific cellular response