To understand or describe any pathway or cycle, start with the following paradigm for the TCA cycle.

Names:
Functions:
Substrates:
Products:
control Enzymes:
Regulation:
Compartment(s):
Tissues of interest:

Name the four dehydrogenase enzymes of the TCA cycle. What are the substrates and products of each reaction?

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What is the approximate energy yield from the oxidation of one acetyl CoA molecule?

Compare NADH and FADH with respect to: (1) Mechanism of accepting or donating electrons, (2) Affinity for the apoenzyme, (3) reactivity in solution, and (4) ability to act as a feedback inhibitor or activator

FAD accepts a single electron, NAD accepts a pair

FAD stays tightly bound to an enzyme, nad acts like a substrate

FAD is more reactive

NAD can have a regulatory role FAD stays bound and cannot.

activation of 2 carbons in the acetylCoA thioester.

Formation of a high energy bond.

Name the five cofactors of the a-ketoglutarate dehydrogenase reaction. Name the vitamins from which four of them are derived! What is the advantage of a multienzyme complex?

thiamine pyrophosphate/thiamine

lipoate/none

FAD/

dihydrolipoyl dehydrogenase/

Efficients transfer without energy loss

Several enzyme reactions in the TCA cycle are considered irreversible. Why?

large negative values for delta G o'

The concentrations never get high enough physiologically to push the reactions backwards

Given the delta-G^0! for each enzymatic step in a sequence of enzymatic reactions, be able to state the delta-G^0! for the overall reaction.

add them up

How is the rate of the TCA cycle linked to muscle contraction and the utilization of ATP?

through the ATP/ADP ratio

citrate synthase is regulated by its product

malate dehydrogenase is regulated by nadh

vinegar

ethanol

sugar

fatty acids

alpha ketoglutarate dehydrogenase

through a common ancestor

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Be able to fully describe the anaplerotic reaction that links glycolysis and the TCA cycle. Name the enzyme, substrate, product, biological compartment and tissues of interest. Name the regulatory factor (activator) and explain how the system regulates the production of the TCA cycle intermediate. What coenzyme is used in the reaction?

Why are the symptoms for pyruvate carboxylase deficiency so apparent in the central nervous system and not in most other tissues?

In addition to pyruvate, name two other classes of compounds that can be used to as substrates for anaplerotic reactions.

Concerning Otto Shape, explain the effect of increased muscle contraction upon the concentrations of ATP, ADP, AMP, NADH, FAD(2H), and Acetyl Co A. What effect does this have upon the rate of the TCA cycle and the pyruvate dehydrogenase reaction?

Concerning Otto Shape, explain the effect of increased muscle contraction upon the concentrations of ATP, ADP, AMP, NADH, FAD(2H), and Acetyl Co A. What effect does this have upon the rate of the TCA cycle and the pyruvate dehydrogenase reaction?

Concerning Otto Shape, explain the effect of increased muscle contraction upon the concentrations of ATP, ADP, AMP, NADH, FAD(2H), and Acetyl Co A. What effect does this have upon the rate of the TCA cycle and the pyruvate dehydrogenase reaction?

Be increasing vascular effiecieny thus allowing more O2 to reach the working muscles

Concerning a patient who suffers from anorexia nervosa and may have developed subclinical deficiencies of many vitamins, which vitamins would you prescribe to be positive that the pyruvate dehydrogenase and the pyruvate carboxylase reactions would have an adequate amount of cofactors?

biotin

ethanol consumption interferes with thiamine absorption

Concerning Al Martini: Given that a-ketoacids build up in the heart in wet beriberi, develop a scenario that would explain why peripheral vessels dilate and cardiac muscles loose their contractility.

perhaps a change in osmotic gradients due to the ketoacids all stay near the heart?  Thiamine injections resolve the issue.

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Because they are linked by the ATP synthase enzyme

Where is complex II found? What reaction of the TCA cycle does it catalyze? How much ATP is produced when 2 electrons of succinate are passed through the chain to O₂? Which complexes couple proton pumping and succinate oxidation?

In the intermembrane/matrix membrane.  The reoxidation of NADH. 

-7Kcal 

Succinate dehydrogenase.

What is the function of an electron in the electron transport chain?

to power the movemet of protons against their concentration gradient

What is a cytochrome?

a heme group associated with a protien

Explain how iron deficiency anemia affects oxygen transport in the blood and oxidative phosphorylation in mitochondria.

It causes fatigue by not providing enough heme groups for the electron transport chain.

How many ATPs are synthesized by ATP synthase for each NADH oxidized by the electron transport chain? How many for FAD(2H)?

NAD = 3 ATP

FAD = 2 ATP

Yes if there is a lack of oxygan it will run backwards.

What portion of the ETC is inhibited by CN^-? What is the effect of cyanide inhibition upon proton pumping and ATP synthesis?

The heme portion of cytochrome aa in cytochrome c oxidase.  It stops electron transport

Why does an impairment of the electron transport chain result in lactic acidosis?

It impairs oxidation of fatty acids

pyruvate builds up

excess pyruvate is converted to lactate

Understand how a chemical uncoupler works. What happens to heat production, proton pumping, ATP synthesis, and NADH utilization following uncoupling?

An uncoupler allows protons to leak back across from the cytosol to the matrix space.  This decreases the proton gradient and slows production of ATP

What is the difference between an inhibitor of electron transport and an uncoupler of electron transport with respect to NADH utilization, proton pumping, and ATP synthase

Uncouplers disengage the clutch

Inhibitors like Cyanide stop the engine.

Symport= phosphate transporter translocate two molecules of different charge

antiport = ANT trasports one molecule for another of similar charge.  works by have the same charge but less of it thus powered by the proton gradient.

Concerning Cora Nari: She had a heart attack. Why was nasal oxygen administered? Why was her blood pressure lowered? What might have been the effect on ATP production if nitroprusside had been continued for several days?

To supply oxygen to the blocked tissues.

To reduce demand on the heart?

It would convert to cyanide and stop the electron transport chain

Concerning Cora Nari: What is TPA and how does it dissolve blood clots?

A recombinant tissue plasminogen activator.  it stimulates conversion of plasminogen back to plasmin

Concerning Cora Nari: How did the change in the ratio of ATP to ADP and AMP affect anaerobic glycolysis? How did this affect the pH?

Anaerobic glycolysis picks up to generate some energy in the abscence of oxygen.  This creates lactic acid and lowers Ph

Concerning X.S.Teefore, Explain how the affect of excess thyroid hormone on oxidative phosphorylation could explain increased appetite and sweating?

The electron transport chain is running to fast thus increasing the need for fuel and creating excess heat.