106: Lec 30 signal t

What are the 2 reasons we need to understand signal transduction?

Helps maintain homeostasis and so we understand medicines targetting these pathways

How do cells mainly communicate chemically?

Extracellular signals secreted by cells that circulate to target cells

What is a hormone with an example?

A hormone is an extracellular signal that is secreted by endocrine glands e.g. insulin

What is an example of paracrine signals?

ACh released at neuromuscular junction (basically NTs)

Example of autocrine signal?

Growth factors

What is signalling by plasma membrane attached proteins and an example?

Recognition of signals that stay on the membrane of another cell e.g. T cell activation by bacteria membrane proteins

What is a receptor?

A molecule in the plasma membrane that detects signal outside, causes conformational change inside, which causes signal transduction

What are the 2 types of ligands and what do they do?

Agonists/partial agonists - produce a response, either maximum or not

Antagonists - produce no response

What are the 3 receptor classes and how do they work/what do they do (brief summary)?

What are 2 mechanisms used in signal transduction pathways and what are they?

When are second messengers produced?

Following receptor activation

Are second messengers embedded in the membrane?

No

What causes the change in concentration of second messengers and what does this change do?

Change conc in response to environmental signals which conveys info to cell

What 3 amino acid residues can a kinase phosphorylate?

Tyrosine, serine, threonine

Can phosphorylation deactivate things?

Yes