8/28 Class 3 Flashcards
Where is cholesterol found?
In the cell wall
Is the cell wall a good place for storage?
Yes, of fatty things.
When is cholesterol fluid rather than rigid?
in low temperatures <37c
*think icecream
How much cholesterol is endogenous?
80%
How much cholesterol is exogenous?
20%
What does statins do?
Reduces the amount of cholesterol being produced by the endogenous system by interfering with the whole cholesterol synthesis pathway.
What is acetyl-CoA?
Big sugary compounds (byproducts of metabolism) that the body can take to use as a substrate to build other things, including cholesterol.
(note that the body often has similar chemical precursors for many outcomes)
How does acetyl-CoA produce ATP?
From glucose and oxygen
What is at the top of the list of things that cholesterol can be turned into?
Sex hormones
What are the sex hormones?
Estradiol E2
Testosterone
Progesterone
What is a precursor to testosterone?
Androstenedione
an·drow·stee·nuh·dee·own
What are the hormones that we talked about that come from cholesterol?
sex hormones
sex hormones precursors
stress hormones
Where are stress hormones made?
The adrenal glands
What are the stress hormones?
Aldosterone
Cortisol
Why don’t stress hormones have “distinct activity”?
They are so similar in shape that their activity isn’t relegated to one kind of receptor. The compound may have different effects on different receptors.
What is required to change a parent compound of cholesterol to a specific hormone?
Enzymes
What does Phosphatidyl refer to?
phospholipid
What are the 4 phosphatidyl compounds?
Phosphatidylinositol
Phosphatidylserine
Phosphatidylethanolamine
Phosphatidylcholine
What is the abbreviation for Phosphatidylinositol?
PI
What is the abbreviation for Phosphatidylserine?
cytosolic
What is the abbreviation for Phosphatidylethanolamine?
PE
What is the abbreviation for Phosphatidylcholine?
PCh
What to do the phosphatidyl groups play a role in?
surfactant
Besides surfactant, what can the phosphatidyl groups be involved in?
Signal transduction processes inside of the cell, or storage of something that can be used for signal transduciton.i.e.inositol is used for smooth muscle contraction
What signal transduction is PI involved in?
smooth muscle contraction
IP3
phosphatidylcholine is used to stash choline in the cell wall, and is eventually used to make _______
acetylcholine
What is Phosphatidylserine used for? How does it work?
Immune marking.
It stays on the inside of healthy cell walls.
Sometimes it can get disoriented and try to cross over to the outside of the cell wall, but typically flipase catches it and puts it back inside.
If the immune system catches it on the outside, the immune system destroys whatever it is attached to.
What keeps Phosphatidylserine inside of the cell wall?
An enzyme called Flipase
In what instance does flipase not catch Phosphatidylserine and flip it back to the inside of the cell?
In a sick cell when the cell itself is using a lot of ATP so no energy is available for Flipase to work.
What is sphingomyelin?
a fatty compound found within the cell wall that is used to create myelin in the nervous system.
What are the precursors found within the cell membrane?
Polyunsaturated fats/lipids
arachidonic acid AA
Phosphatidylinositol
Phosphatidylserine
Phosphatidylethanolamine
Phosphatidylcholine
sphingomyelin
cholesterol
What is an example of a polyunsaturated fat?
arachidonic acids
What is arachidonic acid a parent compound to?
prostaglandins
Name the prostaglandins
PGG2
PGH2
PGE2
PGI2
PGF2alpha
What does TXA2 do?
It mediates the healing of a vessel injury by causing vasospasms. They are released when you injury a blood vessel along with the clotting cascade.
What are the enzymes called that work on the prostaglandin pathway of arachidonic acid?
COX1 and COX2
What do prostaglandins do in the body?
They increase sensitivity to pain
How do we as clinicians reduce pain?
Through the inhibition of the enzymes COX1 and COX2 which then decrease the amount of prostaglandins in the body and therefore reduces sensitivity to pain.
What does COX1 and COX2 do to arachidonic acid?
It catalyzes two chemical reactions to turn arachidonic acid into the precursors pGG2 which turns into PGH2