Exam 3 Condensed Flashcards
When FAs are taken into the mitochondria what form are they in?
Fatty acyl coA
The uptake of FAs into the mitochondria is dependent on what [?]
[cytoplasmic Malonyl-coA]
What is attached to fatty acyl-coA that allows it to enter the mitochondrial matrix?
carnitine
What molecule inhibits the uptake of FAs into the mitochondria?
malonyl-coA
Is FA uptake inhibited or activated by insulin?
inhibited
Is FA uptake inhibited or activated by high [AMP]?
activated
Every 2 carbons, B-oxidation yields…
1 FADH2
1 NADH
1 acetyl coA
What is the cost of 1 round of B-oxidation?
1 ATP (attaching CoA to FA)
Where in the cell does B-oxidation occur?
mitochondrian
What tissues does B-oxidation NOT occur?
brain
RBC
Does insulin inhibit or activate B-oxidation?
inhibits
What tissue is ketone bodies synthesized?
liver
When are ketone bodies synthesized and why?
extended fasting
(excess acetyl coA from lipolysis is used for KB synthesis)
What tissues can use ketone bodies?
What tissues cannot use ketone bodies?
brain
muscles
kidneys
NO - liver & RBC
What is ketosis?
Increased production of ketone bodies after 2-3 days of fasting
What is ketoacidosis?
too many ketone bodies synthesized an not enough degraded acidifying the blood
In the case of diabetic ketoacidosis, what is the state of…
[glucose]
[insulin]
[ketones]
pH
[glucose] – high
[insulin] – low
[ketones] – high
pH – low
In the case of ketotic hypoglycemia, what is the state of…
[glucose]
[insulin]
[ketones]
[glucose] – low
[insulin] – low
[ketones] – high
In the case of non-ketotic hypoglycemia, what is the state of…
[glucose]
[insulin]
[ketones]
[glucose] – low
[insulin] – high
[ketones] – low
What are the 4 names of the ETC complexes?
- NADH DH
- Succinate DH
- Cyt bc1
- Cyt C Oxidase
What are the 2 mobile electron carriers of the ETC?
- Coenzyme Q
- Cytochrome
Which ETC complex DOES NOT pump a proton?
Complex II (Succinate DH)
What’s the final acceptor of electron in ETC?
oxygen
What’s the most important rate regulator of the ETC?
ADP
What are the 2 classes of ETC inhibitors?
Complex I and IV
What are ETC uncouplers?
destroys the pH gradient making the complexes go faster
What are the 4 basic steps of FA synthesis?
- citrate moves out of mitochondria
- citrate –> acetyl coA
- acetyl coA –> malonyl-coA
- FA synthase
What enzyme converts acetyl coA —> malonyl-coA in FA synthesis?
acetyl-coA carboxylase
Each 2 carbons added in FA synthesis, what does it cost?
2 NADPH
1 ATP
1 CO2
What are the 2 sources of NADPH for FA synthesis?
- PPP
- malate DH
What tissue is FA synthesized in?
liver
Does fatty acyl-coA inhibit or activate acetyl-coA carboxylase in FA synthesis?
inhibit
Does insulin inhibit or activate acetyl-coA carboxylase in FA synthesis?
activate
Any FA longer than C____ must be synthesized using elongation
C16
What is the desaturation of FAs?
addition of double bonds
What is the limitation of desaturation of FAs?
can only be done up to C9
How does the body make arachadonate?
How many desaturations and elongations?
converts Linoleate with 2 desaturations and 1 elongation
What are aspirin’s 2 functions?
- inhibit prostaglandins (anti-inflame)
- inhibit thromboxane (anti-coagulant)
Are cis fatty acids solid or liquid?
liquid
Are trans fatty acids solid or liquid?
solid
What are the 3 major sources of trans FAs?
- red meat (gut bacteria)
- heated cis-fats
- dehydrogenated fats
What are the 5 major plasma lipoproteins?
- chylomicrons
- VLDL
- IDL
- LDL
- HDL
What are the 3 types of lipids present in lipoproteins?
- triglycerides
- cholesterol
- phospholipids
What is the primary lipid in chylomicrons and VLDL?
triglycerides
What are the primary lipids in IDL, LDL, HDL?
cholesterol and phospholipids
Does chylomicrons or HDL have more lipids? Which is heavier?
chylomicrons – more lipids
HDL – heavier
Whats the difference between chylomicrons and VLDL?
chylomicrons come from diet (right after eating)
VLDL is synthesized by the liver (a few hours after you eat)
What is the significance of Apo-B100?
marker for LDL (bound to LDL)
What’s the difference between cholesterol and cholesterol esters?
cholesterol esters have FA attached to C3
Does VLDL or chylomicrons have more cholesterol esters?
VLDL
What is the role of LCAT (lectithin) in cholesterol metabolism?
FORMS CHOLESTEROL ESTERS
adds FAs to cholesterol
What are the 3 derivatives of cholesterol?
Bile acid
steroids
Vit D1
Why do statins work so well?
- uptake of LDL via over expression of LDL-R
- reduced de novo cholesterol synthesis
What’s the cause of Kwashiorkor?
low protein intake but enough calories
What are the 2 causes of negative nitrogen balance?
- trauma/stress
- malnutrition
What is the saying for essental amino acids?
Any
Help
In
Learning
These
Little
Molecules
Proves
Truly
Valuble
What does the enzyme ALT do?
convert alanine into pyruvate, for cellular energy production
What is glucogenic v. ketogenic amino acids?
glucogenic – gives rise to glucose from CAC intermediates
ketogenic – gives rise to acetyl coA
How are amino acids absorbed in the intestine v. di- and tri-peptides?
AAs – sodium transporter
peptides – no transporter needed
What is the role of ubquitin in protein degrdation?
tagged on endogenous protein to be degraded by proteasome
What reaction does glutamate DH catalyze?
NH3 + a-ketogluterate –> glutamate
What reaction does glutamine synthase catalyze?
glutamate + NH3 —> glutamine
What are the first 2 steps of amino acids catabolism catalyzed by?
glutamate DH
What is the purpose of NAG in the urea cycle?
regulates the activity of CPS-1 (rate limiting step)
What is the important role of ornithine in the urea cycle?
is a carrier like OXA
- also makes citrulline which leaves mitochondria
How does lactulose lower ammonia in the blood?
gut bacteria ferment it
gut acidified
NH3 from blood moves into gut and is protonated into NH4
