Amphibolism in Kreb Cycle

1. AMPHIBOLIC ROLE OF KREBS CYCLE WITH
SPECIAL REFERENCE TO ANAPLEROTIC
REACTIONS
Presented By
Morjina Parveen
Supervised by- Tridip Boruah Roll No.- 05
Assistant Professor MSc 2nd semester
MC College, Barpeta MC College, Barpeta

2. CONTENTS
 Amphibolism
 Amphibolic nature
 Overview
 Anaplerosis
 References

3. WHAT IS AMPHIBOLISM ?
 Amphibolism can be described as the biochemical pathway where both the
processes anabolic and catabolic are involved.

4. Amphibolic nature of Krebs Cycle
 Contains both catabolic and anabolic reactions.
Anabolic- Several intermediates are precursors in biosynthetic
pathways.
Catabolic- Energy from oxidation of acetyl CoA is stored in reduced
coenzymes.

5. An overview of Krebs cycle
 Discovered by Hans Adolf Krebs .
 Also called Citric Acid cycle or Tricarboxylic acid cycle.
 Includes a series of oxidation-reduction reactions in the matrix of
mitochondria (eukaryotes).
 Results in the oxidation of an acetyl group to two molecules of carbon
dioxide and reduce the coenzymes that are reoxidized through the electron
transport chain.

7. An overview on the anabolic reactions
The cycle is engaged in synthetic(anabolic) reactions by following
ways:
 Mitochondrial citrate is transported to the cytosol, where it is cleaved to
provide acetyl-CoA for the biosynthesis of fatty acids, sterols.
 Oxaloacetate and α-ketoglutarate, respectively, serves as precursors for
the synthesis of aspartate and glutamate which, in turn, are required for the
synthesis of other non-essential amino acids, purines and pyrimidines.
 Succinyl-CoA is used for the synthesis of porphyrins and heme.

8. An overview on the catabolic reactions
 Krebs cycle is a catabolic pathway because it oxidizes acetyl-CoA
into CO2 and H2O and makes NADH, FADH2 and GTP.

9. Anaplerosis
 It is a series of enzymatic reations in which metabolic intermediates enter
the citric acid cycle from the cytosol.
 The reaction catalyzed by pyruvate carboxylase that replenishes
oxaloacetate to the Krebs cycle is a good example of an anaplerotic or
“filling up” reaction.

10. ANAPLEROTIC REACTIONS,

11. REFERENCES
 Life Sciences by Pranav Kumar and Usha Mina.
 https://youtu.be/EDWgs?si=QrMlcYnfTdRV6kpM.
 https://youtu.be/wdXaDrM6Ei0?si=auLyRl40e7RE6_FE.

12. THANK YOU