Lecture 1 - Cell Biology Flashcards
How long does protein synthesis take?
Between 2-24 hrs
What determines cell function
Protein composition
Do steroids pass easily through membrane?
Yes, they are lipids and are thus lipid soluble
Mechanism by which lipid-soluble hormones affect cell function?
Enter the through the lipid membrane, bind to receptors which bind to DNA and regulate mRNA synthesis. The protein synthesis then takes place, which is slow (2-24 hrs)
Can water soluble molecules pass through the membrane?
No. Must bind to surface receptor which affects ion channels, coupling proteins, etc.
What produces cAMP from ATP?
What breaks cAMP down?
Adenylyl Cyclase - enzyme
Phosphodiesterase
How does cAMP regulate function of cell?
Directly
Also by activating cAMP-dependent protein kinase that phosphorylates other proteins
Adenylyl Cyclase System consists of two what?
G-proteins. Gs and Gi
Gs stimulates system
Gi inhibits
What does Phospholipase A2 do?
Cuts phospholipids to release arachidonic acid from glycerol backbone
What is arachidonic acid converted to?
Many active metabolites
What are arachidonic metabolites involved in?
pain, temperature regulation, allergies, asthma, inflammation
What do COX inhibitors do?
Decrease inflammation by inhibiting metabolite production
What’s a down side to COX inhibitors?
They may cause asthma.
If you block COX, then more lypoxygenase metabolites are formed, which may cause asthma. lypoxygenase is one of the three arachidonic acid breakdown paths.
What is used to treat asthma?
Lipoxygenase inhibitors.
Also used to treat hay fever and allergies.
What does PLC hydrolyze and what does that hydrolysis produce?
hydrolyzes PIP2
produces: diacylclycerol and IP3 (inositol 1,4,5-triphosphate)
