Pyruvate Dehydrogenase Complex

0.0(0)
Studied by 0 people
call kaiCall Kai
learnLearn
examPractice Test
spaced repetitionSpaced Repetition
heart puzzleMatch
flashcardsFlashcards
GameKnowt Play
Card Sorting

1/18

encourage image

There's no tags or description

Looks like no tags are added yet.

Last updated 8:51 PM on 4/6/26
Name
Mastery
Learn
Test
Matching
Spaced
Call with Kai

No analytics yet

Send a link to your students to track their progress

19 Terms

1
New cards

Pyruvate Dehydrogenase Complex function

catalyzes the oxidative decarboxylation of pyruvate to acetyl-CoA

2
New cards

location of the pyruvate dehydrogenase complex

mitochondrial matrix

3
New cards

what needs to happen to pyruvate for oxidative decarboxylation to happen

it must cross both mitochondrial membranes

4
New cards

oxidative decarboxylation of pyruvate reaction

pyruvate + CoA + NAD+ ——> Acetyl-CoA + CO2 + NADH

5
New cards

oxidative decarboxylation of pyruvate reaction ΔG°'

-33.4 kJ/mol so irreversible

6
New cards

Pyruvate dehydrogenase complex

a massive multienzyme complex with three enzymes

7
New cards

What are the three enzymes that compose the pyruvate dehydrogenase complex

  1. Pyruvate dehydrogenase (TPP cofactor)

  2. Dihydrolipoyl transacetylase (Lipoate, CoA)

  3. Dihydrolipoyl dehydrogenase (FAD, NAD+)

8
New cards

What are the five coenzymes required for the oxidative decarboxylation of pyruvate

  1. TPP - thiamine pyrophosphate

  2. Lipo - lipoate

  3. FAD - flavin adenine

  4. CoA - coenzyme A

  5. NAD - nicotinamide adenine dinucleotide

9
New cards

pyruvate dehydrogenase complex mechanism step 1

Decarboxylation (E1 + TPP)

  1. pyruvate binds to TPP

  2. CO2 released

  3. Hydroxyethyl-TPP formed

10
New cards

pyruvate dehydrogenase complex mechanism step 2

Oxidation (E1 → E2)

  1. hydrozyethyl group transferred to lipate

  2. oxidized to acetyl group

  3. lipoate reduced to dihydrolipoate

11
New cards

pyruvate dehydrogenase complex mechanism step 3

Transfer to CoA (E2)

  1. acetyl group transferred to CoA

  2. Acetyl-CoA released

12
New cards

pyruvate dehydrogenase complex mechanism step 4-5

Regeneration (E3)

  1. dihydrolipoate oxidized by FAD

  2. FADH2 oxidized by NAD+

  3. NAD+ → NADH

13
New cards

Why is the pyruvate dehydrogenase complex highly regulated

because it controls entry into the TCA cycle

14
New cards

Allosteric regulation of pyruvate dehydrogenase complex: inhibitors

  • Acetyl-CoA

  • NADH

  • ATP

15
New cards

Allosteric regulation of pyruvate dehydrogenase complex: activators

  • CoA

  • NAD+

  • ADP

16
New cards

PDH kinase

phosphorylates E1 → inactivates PDC

17
New cards

PDH phosphatase

dephosphorylates E1 → activates PDC

18
New cards

Insulin

activates phosphatase → PDC on

19
New cards

Glucagon

activates kinase → PDC off