Biochemistry
Study Guide
Authored by a Biochemistry Professor
METABOLISM MASTERY
BUNDLE
TCA Cycle • Gluconeogenesis • Glycogen •
Pentose Phosphate Pathway
,Author: Assoc. Prof. Dr Zeynep Caliskan, Department of Medical
Biochemistry
Copyright © 2025 The Curious Biochemist. All rights reserved
No part of this publication may be reproduced, distributed, or
transmitted in any form or by any means, electronic or mechanical,
including photocopying, recording, or by any information storage
and retrieval system, without the prior written permission of the
author.
Disclaimer
This study guide has been prepared solely for educational and
academic purposes. The content is based on standard medical
textbooks and is not intended to replace clinical judgment or
professional medical advice. Students are advised to consult
qualified healthcare professionals in real clinical settings.
Contents
Citric Acid Cycle ............................................................. Page 3
Gluconeogenesis ............................................................ Page 10
Glycogen Metabolism ................................................... Page 18
Pentose Phosphate Pathway ....................................... Page 25
, 3
CITRIC ACID CYCLE
(KREBS CYCLE/TRICARBOXYLIC ACID (TCA) CYCLE
GENERAL
• The TCA cycle plays multiple roles in metabolism.
• Its primary function is to produce energy by breaking down acetyl-CoA into
carbon dioxide. Acetyl-CoA is derived from the metabolism of fuel molecules like
amino acids, fatty acids, and carbohydrates.
• The cycle also serves as a metabolic crossroads for various metabolic pathways,
including gluconeogenesis, lipogenesis, amino acid transamination, heme
synthesis, and ketone breakdown.
"Citric acid cycle" by Theislikerice/ Wikimedia Commons/CC BY-SA 4.0
Study Guide
Authored by a Biochemistry Professor
METABOLISM MASTERY
BUNDLE
TCA Cycle • Gluconeogenesis • Glycogen •
Pentose Phosphate Pathway
,Author: Assoc. Prof. Dr Zeynep Caliskan, Department of Medical
Biochemistry
Copyright © 2025 The Curious Biochemist. All rights reserved
No part of this publication may be reproduced, distributed, or
transmitted in any form or by any means, electronic or mechanical,
including photocopying, recording, or by any information storage
and retrieval system, without the prior written permission of the
author.
Disclaimer
This study guide has been prepared solely for educational and
academic purposes. The content is based on standard medical
textbooks and is not intended to replace clinical judgment or
professional medical advice. Students are advised to consult
qualified healthcare professionals in real clinical settings.
Contents
Citric Acid Cycle ............................................................. Page 3
Gluconeogenesis ............................................................ Page 10
Glycogen Metabolism ................................................... Page 18
Pentose Phosphate Pathway ....................................... Page 25
, 3
CITRIC ACID CYCLE
(KREBS CYCLE/TRICARBOXYLIC ACID (TCA) CYCLE
GENERAL
• The TCA cycle plays multiple roles in metabolism.
• Its primary function is to produce energy by breaking down acetyl-CoA into
carbon dioxide. Acetyl-CoA is derived from the metabolism of fuel molecules like
amino acids, fatty acids, and carbohydrates.
• The cycle also serves as a metabolic crossroads for various metabolic pathways,
including gluconeogenesis, lipogenesis, amino acid transamination, heme
synthesis, and ketone breakdown.
"Citric acid cycle" by Theislikerice/ Wikimedia Commons/CC BY-SA 4.0
