Exam 1 - Lecture 3 8/28 Flashcards
Sources of cholesterol
Exogenous 20% and endogenous 80%
Why is cholesterol hard to lower by just diet?
Most of your cholesterol, 80%, is made in the body and not by the food you eat. Statins medication will better help lower cholesterol.
6 compounds of cholesterol metabolites
E2 estradiol, Testosterone, Progesterone, aldosterone, Androstenedione, and Cortisol
What is progesterone?
Cholesterol metabolite, sex hormone
Aldosterone
Stress hormone in the adrenal glands
Cortisol
Stress hormone in the adrenal glands
What’s the similarity between aldosterone and cortisol?
They are both secreted by adrenal gland and their compounds are extremely similar. They may be able to attach themselves to each others receptors due to similarities. If Aldosterone is low, cortisol may be able to bind to aldosterone receptors.
E2 Estradiol
Sex hormone
Androstenedione
Testosterone precursor, baseball players used this back in the 90’s as performance enhancing.
Testosterone
Sex hormone
Arachidonic Acid
Imp precursor. Long, large fatty acid chains that hangout in cell walls. Parent compound to many things such as cox1/2, prostaglandins, HETE/EET, Leukotrines
PhosphatidylINOSITOL (PI)
On the polar head of the phospholipid, found in the smooth muscle to regulate contraction.
PhosphatidylSERINE (cytosolic)
Immune marker, should stay inside cell wall if the cell is healthy. When unhealthy, it will stick outside the cell and be an immune marker for the body to attack it. Related to flipase enzyme
Flipase
Enzymes in cell wall that will correct serine from being outside the cell, flips it back inside cell. Need good supply of ATP to do this, and when a dying cell runs out of ATP that is why the sick cell then has serines on the outside because flipase can’t do its job.
PhosphatidylETHANOLAMINE (PE)
NOTHING SPECIAL LOL
PhosphatidylCHOLINE (PCh)
Storage molecule for transduction. Stashes choline, needed for acetylcholine.
What do all Phosphatidyl- precursors play a role in?
Lung surfactant
Sphingomyelin
Fatty compound for body to construct myelin
1st arachidonic pathway
COX1/COX2 enzymes create PGG2 -> PGH2 used e2 synthase to produce -> PGE2/PGI2/PGF2alpha/TXA2
What are the prostaglandins compounds and what do they do?
PGE2/PGI2/PGF2alpha: ramp up pain signals, help you notice pain.
TXA2
Thromboxane A2: helps tighten blood vessels during clotting cascade to prevent further bleeding.
How is aspirin related to COX1/COX2?
Aspiring inhibits the enzymes for this pathway to prevent pain, this is why dilated blood vessels/further bleeding is a side effect of aspirin. More related to COX1.
What drug is specific to COX2 for pain?
Naproxen.
COX2
Inactive until body senses pain, then it is activated.
COX1
Active all the time, more specific to TXA2 production.
2nd pathway for Arachidonic acid
Enzyme: Lipocygenase (5-LO—FLAP) -> 5HPETE -> LTA4 -> LTC4/LTD4/LTE4
LTC4/LTD4/LTE4
Leukotrines: part of bodies immune response, causes inflammation.
1st degree ACTIVE transport
Na+/K+ pump, Ca++ pump, H+ pump. All use ATP, and the enzyme ATPase. They are going against chemical/electrical gradient, and/or speeding up the process, therefore they use energy.
3rd pathway for Arachidonic acid
HETE/EET: fatty, short living. present in acute renal failure
How does ATP work in pump channels?
A phosphate is removed from ATP, converting it to ADP and releasing energy to move ions.
Simple diffusion
Gas and electrolytes/channel proteins.
How does simple diffusion move things in and out of cell without ATP/using energy?
Chemical or electrical gradient. e.g. Gas moves across membrane without difficulty, if there is more gas outside cell than inside, then it will naturally move inside the cell. For electrical, sodium is naturally positive so if cell is negative it may bring sodium inside the cell via a sodium channel.
Facilitated diffusion
Binding to compound forcing conformational change, which then releases compound on the other side of the cell.
H2O pumps
Move water in and out of the cell via AQP (aquaporin). h2o may even use electrolyte channels if there are no h2o pumps.
Na+/K+ pumps
1st degree active transport, uses ATP. 3 Na+ move outside the cell, in exchange for 2 K+ to move inside the cell. This goes against electrical gradient, which is why it requires ATP. 10x more Na+ outside the cell than in, and 30x more K+ inside the cell than out.
What is the highest energy process in the body?
Na+/K+ pumps
Ca++ pumps
1st degree active transport, requires ATP. Must move all calcium outside the cell, 10,000:1 ratio.
H+ pumps
1st degree active transport. Moves H+ outside the cell. e.g. in the stomach, needs to have low pH. H+ is very acidic, so pumping H+ into the stomach.
Secondary active transport
Don’t directly use ATP, but rely on 1st degree pumps to be active in the cell in order for them to function.
-NCX transporter, aka Na+/Ca++ exchanger.
-Na+ Glucose
NCX Transporter
AKA sodium calcium exchanger: form of secondary active transport, facilitated diffusion. 1 calcium moved outside the cell, 3 sodiums moved inside the cell. uses Na+ gradient to get into cell, and this happens when too much calcium is inside the cell.
Na+ Glucose pump
Secondary active transport. Speeds up glucose getting inside the cell, using Na+ gradient. Mostly found in kidneys.
Glut-4 transporter
95% of the time how glucose gets inside the cell. Glucose is charged, polar, hydrophilic and does not require energy (facilitated diffusion). Glucose binds to outside of cell, causes conformation change, and rotates inside the cell to be dropped off and used (burned).
How do you get more glut-4 transporters? Where are they found?
Give insulin. Throughout the body (liver, musculoskeletal cells, adipose tissue.)
Glut-1
found in red blood cells, not insulin dependent.
