Metabolites are constantly on a journey traveling through biochemical pathways over time. How they travel and where they end up gives biochemists a clue on the cellular physiology, morphology, behavior and disease states especially cardiovascular diseases, neurodegenerative diseases and cancer. This lesson introduces the key concept of metabolic flux and how these biochemical journeys look. The lesson is intended for the undergraduate level of biochemistry and metabolism students, but could be useful to other trainees as well. See the lesson chapters below to learn more.


Metabolites go on journeys

This chapter introduces metabolic flux as a key concept in biochemistry and why one needs to study it

Metabolites go on specific journeys

Short animations will show a few common central carbon metabolism pathways - Glycolysis, Fermentation, TCA cycle, Pentose Phosphate Pathway, Malate-Aspartate shuttle and conversion of Citrate to Fatty Acid

Journeys are interconnected 

Animations will show integrated central carbon metabolism pathways and journey of carbon through glucose, glutamine and fatty acids

Journeys can change

This chapter delineates how flux can be altered under different conditions such as hypoxia and during cancer


1. Describe metabolic flux in the context of common biochemical pathways of central carbon metabolism.

2. Visualize carbon flux from glucose (a sugar) and glutamine (an amino acid) into central carbon metabolism pathways.

3. Understand how metabolic flux can be altered under different conditions and its significance.

4. Identify ways to measure metabolic flux.

This lesson supports education of a 'Threshold Concept' in Biochemistry - Biochemical pathway dynamics and regulation identified by the American Society for Biochemistry and Molecular Biology (ASBMB). According to ASBMB, 'Threshold Concepts are concepts and skills that, when mastered, represent a transformed understanding of a discipline, without which the learner cannot progress.'

Background Knowledge

This lesson is complementary to introductory classes in metabolism that cover homeostasis and principles of kinetics to describe flux through biochemical pathways. The students should be learning about catabolism of nutrient molecules such as carbohydrates, lipids and proteins, and their anabolism into storage and structural molecules to appreciate the lesson. They should also be familiar with redox reactions and terms oxidation and reduction. The content is only in English as of June 2021.


This lesson was designed by Shraddha Nayak, a postdoctoral fellow in the Animation Lab at the University of Utah with guidance from lab members and its head, Janet Iwasa. It was made in collaboration with biochemists, Greg Ducker and Jared Rutter. Input was received from educators, Janet Lindsley, Rebecca Roston, Antentor O Hinton, Stephanie Walker, Jessica Fry, Sabrice Guerrier, Cassidy Terrell and Debora Guerini de Souza. Scientists Melanie McReynolds, Marcia Haigis and Alison Ringel Moreno also gave their feedback. We thank the FY20 Nuclear Control of Cell Growth and Differentiation (NC) Program Award - Huntsman Cancer Institute for partially funding this project.