Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
22 Cards in this Set
- Front
- Back
|
Why is the citric acid cycle said to be amphibolic?
|
It acts in both an anabolic and a catabolic way.
|
|
|
what are the catabolic functions of the TCA cycle?
|
It oxidises the two carbons of acetyl CoA to carbon dioxide in order to create NADH and FADH, these products will be used in OXPhos to make most of the cellular energy.
|
|
|
What are the anabolic functions of the TCA cycle?
|
It provides the starting material for the production of glucose, amino acids, fatty acids, heme, and many other cellular components.
|
|
|
Why is the TCA cycle considered strictly aerobic?
|
because the NAD and FAD cofactors for the dehydrogenase reaction must be continuously regenerated by the electron transport chain (from NADH and FADH) and the terminla electron acceptor for the OXPhos cyle is Oxygen.
|
|
|
What is the fuel for the TCA cycle, and where does it come from?
|
The main fuel is acetyl Coa. Acetyl CoA comes from pyruvate.
The reaction is as follows. pyruvate+NAD==> Acetyl CoA + NADH by the enzyme pyruvate dehydrogenase. |
|
|
What can citrate go on to do in the cell?
|
It can be a carbon source for fatty acids and can control glycolysis.
|
|
|
What can alpha ketoglutarate go on do in the cell?
|
makes glutamate, one of the most important non essential neurotransmitters.
|
|
|
What can succinyl CoA go on to do in the cell?
|
Provides the Carbons for heme synthesis.
|
|
|
What can oxaloacetate go on to do?
|
It is the starting material for glucose synthesis and aspartate.
|
|
|
Where in the cell does the citric acid cycle take place?
|
The matrix of the mitochondria.
|
|
|
Where does Oxidative Phosphorylation take place?
|
Within and across the inner mitochondrial membrane.
|
|
|
How many molecules of reduced cofactors are produced by the oxidation of one molecule of acetyl coa?
|
One GTP, three NADHs, one FADH.
|
|
|
How many molecules of reduced cofactors are produced by the oxidation of one molecule of glucose?
|
Glucose will make two acetyl CoA's, and thus will allow the cycle to run twice.
|
|
|
How many ATP's are generated through OXPhos during the oxidation of NADH, and FADH2? Why?
|
NADH= 3 ATP
FADH2= 2 ATP This is because NADH is able to interact with all 4 proteins of the OXPhos cycle, while FADH is only able to interact with the last three. Only proteins one, three, and four make ATP. |
|
|
Why is pyruvate dehydrogenase an importand enzyme? What contolls it?
|
Pyruvate dehydrogenase is the enzyme responsible for making acetyl coa from pyruvat, and thus supplies the fuel for the TCA cycle and thus OXPhos.
|
|
|
How is pyruvate dehydrogenase controlled?
|
Stimulated by NAD+, Ca, and insulin.
Inhibited by Acetyl Coa, NADH and low levels of insulin. |
|
|
Why is pyruvat carboxylase important?
|
It takes pyruvate and makes oxaloactetate.
|
|
|
The oxidation of one mole of glucose via glycolysis and the TCA cycle produce how many ATP?
|
Thirty.
|
|
|
What is the role of the proton gradient in OXPhos, and how is it created?
|
The proton gradient serves to provide the force to turn the ATP synthase enzyme and allows the transere of and inorganic P to an ADP thus creating ATP. This gradient is formed as a result of NADH and FADH2 passing their electrons through the protiens of the ETC.
|
|
|
What are the two characteristics of an uncoupler how does one work?
|
Uncouplers are lipphilic weak acids that allow protons to pass through the inner mitochondrial matrix, thus destroying the gradient.
|
|
|
Where within the cell does OXPhos occur?
|
On the surface of the inner mitochondrial membrane.
|
|
|
Which enzymes of the citric acid cycle have been identified as tumor supressors?
|
Defects in succineal and Fumarate ases have been associated with tumors. In other words, people with too much fumarate or succinate have tumors.
|
