Flashcards in 1: Physiology: TCA class notes Deck (17):
What is the TCA cycle?
Acetyl-CoA molecules derived from pyruvate, VFAs, FAs, and AAs are condensed with oxaloacetate to form citrate molecules that are subsequently oxidized in the presence of oxygen.
AAs can also be oxidized in the TCA cycle after they are converted (via deamination and transamination) into TCA intermediates.
What is the major function of the TCA cycle?
is to oxidize substrate and generate reduced cofactors such as NADH.
the reduced cofactors are subsequently oxidized in the electron transport chain in the presence of oxygen to ultimately phosphorylate ADP to ATP.
What can be catabolized into acetyl CoA?
carbs, protein, and lipids
acetyl CoA is oxidized subsequent to condensation with oxaloacetate.
Acetyl CoA can not be oxidized in the absence of what?
oxaloacetate is supplied by carbs and amino acids (derived from protein)
Subsequent to deamination and transamination, amino acids derived from protein may enter the cycle as?
as of the TCA intermediates.
What is used to make what in the TCA cycle?
pyruvate is used to make acetyl CoA
Acetyl CoA is condensed with what?
it is condensed with oxaloacetate to produce citrate (it is not oxidized)
Glucose can be used to make what to be used in the TCA cycle?
it can be turned into oxaloacetate and into acetyl CoA to be used in the TCA cycle.
How do lipids play a role in the TCA cycle?
hey can be turned into Acetyl CoA to be used
However they can not be turned into oxaloacetate
What happens if you are not taking in any carbs?
your body cannot burn any fat that is in storage.
so you just keep accumulating fat and storing it.
Do proteins play a role in the TCA cycle?
proteins can be made into oxaloacetate and Acetyl CoA however you can not produce enough of either to keep it going because it is expensive to make protein in the body= energy intensive so tend not to burn (use) it quickly
As electrons are transported down the electron transport chain the mitochondria is making how many ATP molecules?
What happens in the mitochondria as NADH is oxidized to NAD+?
an electron sent in IMMs reduced and gets oxidized by the next electron and that one reduced and just keeps going.
this makes energy.
The energy made by the electrons in the IMM are used to do what?
used to move protons to other side of the membrane which cause a high proton content on one side of the membrane and low on the other and this creates a concentration gradient.
When the concentration gradient is made what happens?
energy is expended to make it and some energy is stored as potential energy.
cells can tap that energy to use the concentration gradient to do work.
What is phosphoralated to get ATP?