Krebs Cycle and Pyruvate Dehydrogenase Chapter 17

These flashcards cover key concepts, processes, and regulatory mechanisms involved in the Krebs cycle and the role of pyruvate dehydrogenase.

What happens to pyruvate after glycolysis?

Pyruvate can be converted into Acetyl-CoA, lactate, or ethanol depending on aerobic or anaerobic conditions.

Which cycle does Acetyl-CoA enter after its formation?

Acetyl-CoA enters the Krebs cycle (Citric Acid Cycle).

What is the role of pyruvate dehydrogenase in cellular respiration?

Pyruvate dehydrogenase catalyzes the conversion of pyruvate to Acetyl-CoA, producing NADH and releasing CO2.

Which vitamins are involved in the formation of coenzyme A?

Vitamin B5 (Pantothenic Acid) is necessary for the synthesis of coenzyme A.

What discovery did Hans Adolf Krebs make?

He discovered the citric acid cycle (Krebs cycle) and its role in metabolism.

What is the first committed step of glycolysis?

The first committed step is catalyzed by Phosphofructokinase (PFK) which converts Fructose-6-phosphate to Fructose-1,6-bisphosphate.

Name the products of the citric acid cycle per acetyl-CoA.

The products include 3 NADH, 1 FADH2, 1 GTP (or ATP), and 2 CO2.

Which enzymes catalyze the conversions in the citric acid cycle?

Key enzymes include citrate synthase, aconitase, isocitrate dehydrogenase, and α-ketoglutarate dehydrogenase.

What regulates the activity of the Krebs cycle?

The activity is regulated by energy status indicators such as NADH, ATP, ADP, and Ca2+.

What is the chemical reaction that occurs in the formation of Acetyl-CoA?

The reaction is pyruvate + CoA + NAD+ → Acetyl-CoA + CO2 + NADH.