Acetyl CoA and the TCA cycle

Come back and finish this quizlet when are not brain dead

What are the 3 stages of cellular respiration?

1. glycolysis (makes acetyl CoA)

2. TCA cycle (Acetyl CoA is oxidized into Co2 and NAD+ and FAD are reduced)

   3.Oxidative phosphorylation (e- from fuel molecules are transferred to O2 and ATP is produced)

What are many redox reactions catalyzed by?

dehydrogenases

Where does glycolysis take place?

cytoplasm

Where does the TCA cycle take place?

mitochondria

What is the end product of glycolysis?

pyruvate (then used in the TCA cycle in the mitocondria)

What is the purpose of Acetyl coenzyme A (acetly CoA) in the TCA cycle?

delivers 2 carbons from pyruvate and acts as a carrier enzyme in the TCA cycle. (it is often linked to B vitamins so being decieent in B vitamins can make the TCA cycle less effective)

How would the pyruvate levels differ in a person affected with beriberi versus a healthy

individual?

elevated levels of pyruvate in the blood

how is pyruvate dehydrogenase regulated?

1. feedback inhibition (presence of acetyle CoA and NADH will turn it off AKA adequet levels of APT)

2. enzymatic regulation (gets phosphorized to turn it of) (kinase: if pyruvate dehydrogenase kinase (pDK1) turns on when acetyl CoA and NADH are present, when PDK1 is active is phosphorized pyruvate dehydrogenase to turn it off)

pyruvate dehydrogenase is ____ where there is no energy demand?

inactive

Which of the following activates pyruvate dehydrogenase kinase?

1. NAD

2. Acetyl CoA

3. ADP

4. Pyruvate

B acetyl CoA

Acetyel CoA combines with oxaloacetate to form what?

citrate

Are dehydrogenase reactions in the TCA cycle energy-requiring or energy yielding reactions?

energy yeilding

How is the TCA cycle regulated?

1. through feedback inhibition (availability of substrates)

2. levels of ADP and ATP

3. negatively regulated by NADH

4. activated or deactivation of dehydrogenase enzymes

What does pyruvate carboxylase do?

converts pyruvate directly into oxaloacetate (common in liver and nervous tissue)