Lecture 3 Flashcards
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What is the cell wall made of?
Phospholipid bilayer
What does a phospholipid consist of?
A head: polar group, phosphate, and glycerol
A tail: Fatty acid chain
Describe the tail of a phospholipid?
Fatty acid chain consisting of carbons and hydrogens; uncharged and hydrophobic; oily; on the inner part of the cell wall
Describe the head of a phospholipid?
A charged compound; hydrophilic; oriented to the outer cell wall
What end of the cholesterol structure will stuck out of the cell wall?
HO-
What 2 terms describe a cholesterol?
Planar (flat) and rigid
What does cholesterol do to food?
Changes the texture to more smooth
What does cholesterol do to blood vessels?
More rigid
Can we remove cholesterol from food? What happens when we do?
Yes.
Food texture becomes gross
What are the main type of metabolites of cholesterol?
Sex hormones!
What is the precursor to cholesterol?
What type of compound is this?
Acetyl-CoA and Acetoacetyl-CoA
HMG synthase
What type of drug would you need to combat high cholesterol? And why?
HMG-CoA reductase inhibitor
-vastatin
It inhibits the precursor to cholesterol therefor it interferes with the pathway
What percentage of cholesterol does our body make vs how much is eaten?
Body - 80%
Eaten (exogenous) - 20%
Can you tackle high cholesterol via diet changes?
Yes and no. Only 20% of cholesterol in our bodies come from foods that we eat. We might see a small decrease but we need drugs to help because our bodies are producing 80% of total body cholesterol.
What are the sex hormone metabolites of cholesterol?
Estradiol
Testosterone
Estrogen
Progesterone
Androstenedione
What are the stress hormone metabolites of cholesterol? And what is special about them?
Cortisol and Aldosterone
They are both produced in the adrenal gland and they have cross reactivity because their structures are so similar
What is the precursor to testosterone?
Androstenedione
What is adrostenedione?
A cholesterol metabolite that is a precursor to testosterone
How is a cholesterol metabolite created?
Enzymatic action manipulates the original structure of cholesterol.
If there is no enzyme then you cannot create the metabolite.
What are the “specialized” phospholipids?
Phosphatidylinositol (PI)
Phosphatidylserine (cytosolic)
Phosphatidylethanolamine (PE)
Phosphatidylcholine (PCh)
(Phosphatidyl- phosphate with an attached compound)
What is Phosphatidylinositol (PI)?
Stores IP3 (Inositol triphosphate) to be used for energy during smooth muscle contractions.
What is Phosphatidylserine (cytosolic)?
acts as an immune marker; attached to cell wall on the inside of the cell. When it goes to the outside of the cell wall the body triggers an immune response.
What helps keep
Phosphatidylserine (cytosolic) inside the cell? Describe it.
Flippase; flippase is an enzyme that is stuck in the cell wall that makes sure phosphatidylserine does not migrate the the outer cell. It requires ATP
What happens when Phosphatidylserine (cytosolic) is present on the outside of the cell and the cell does not have ATP?
Flippase will not be able to flip the Phosphatidylserine back to the inside of the cell. Therefore more Phosphatidylserine will become present on the outer cell wall. The body will trigger an immune response to degrade the cell.
What is phosphatidylcholine (PCh)?
Used to store choline which is use in signal transduction.
What is phosphatidylethanolamine (PE)?
PE helps with the maintenance of the structure and function of surfactant in the lungs.
What is Sphingomyelin?
It is a fatty compound that the body uses to make myelin in the nervous system
What is an arachidonic acid?
A long amino acid with saturated and unsaturated areas that is stuck in the cell wall.
What are the 3 important pathways called that metabolite from arachidonic acid?
Prostaglandin/Thromboxane
Leukotriene
EET/HETE
What are the enzymes used in the Prostaglandin/Thromboxane pathway?
COX1 and COX2
PG =
Prostaglandin
TX =
Thromboxane