Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Electron Transport Chain: Complex III and IV01:43

Electron Transport Chain: Complex III and IV

During the electron transport chain, electrons from NADH and FADH2 are first transferred to complexes I and II, respectively. These two complexes then transfer the electrons to ubiquinol, which carries them further to complex III. Complex III passes the electrons across the intermembrane space to Cyt c, which carries them further to complex IV. Complex IV donates electrons to oxygen and reduces it to water. As electrons pass through complexes I, III, and IV, the energy released aids the pumping...
Pyruvate Oxidation01:15

Pyruvate Oxidation

After glycolysis, the charged pyruvate molecules enter the mitochondria via active transport and undergo three enzymatic reactions. These reactions ensure that pyruvate can enter the next metabolic pathway so that energy stored in the pyruvate molecules can be harnessed by the cells.
First, the enzyme pyruvate dehydrogenase removes the carboxyl group from pyruvate and releases it as carbon dioxide. The stripped molecule is then oxidized and releases electrons, which are then picked up by NAD+...
Regulation of Metabolism01:19

Regulation of Metabolism

Cellular needs and conditions vary from cell to cell and change within individual cells over time. For example, the required enzymes and energetic demands of stomach cells are different from those of fat storage cells, skin cells, blood cells, and nerve cells. Furthermore, a digestive cell works much harder to process and break down nutrients during the time that closely follows a meal compared with many hours after a meal. As these cellular demands and conditions vary, so do the amounts and...
Other Glycolytic Pathways01:24

Other Glycolytic Pathways

The pentose phosphate pathway (PPP) operates in parallel with glycolysis, facilitating the metabolism of both pentoses and glucose. This pathway consists of two distinct phases: the oxidative and non-oxidative phases. While it does not directly generate ATP, the intermediates formed during the process can integrate into glycolysis, contributing to cellular energy metabolism when required.Oxidative Phase: NADPH ProductionThe oxidative phase of the pentose phosphate pathway is primarily...
What is Glycolysis?00:56

What is Glycolysis?

Overview
Cells make energy by breaking down macromolecules. Cellular respiration is the biochemical process that converts "food energy" (from the chemical bonds of macromolecules) into chemical energy in the form of adenosine triphosphate (ATP). The first step of this tightly regulated and intricate process is glycolysis. The word glycolysis originates from the Latin glyco (sugar) and lysis (breakdown). Glycolysis serves two main intracellular functions: generating ATP and generating...
Electron Transport Chain: Complex I and II01:46

Electron Transport Chain: Complex I and II

The mitochondrial electron transport chain (ETC) is the main energy generation system in the eukaryotic cells. However, mitochondria also produce cytotoxic reactive oxygen species (ROS) due to the large electron flow during oxidative phosphorylation. While Complex I is one of the primary sources of superoxide radicals, ROS production by Complex II is uncommon and may only be observed in cancer cells with mutated complexes.
ROS generation is regulated and maintained at moderate levels necessary...

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Relation between Exercise Training-Induced Changes in Oxygen Uptake Kinetics and the Power-Duration Relation.

Medicine and science in sports and exercise·2026
Same author

Mechanisms underlying age-related changes in the human skeletal muscle bioenergetic system.

European journal of applied physiology·2026
Same author

The effect of AMP deamination on skeletal muscle is stronger and more beneficial in extremely intense exercises to exhaustion and/or extremely stressing conditions.

European journal of applied physiology·2025
Same author

P<sub>i</sub>-based mechanism of muscle fatigue during all-out exercise in humans.

Respiratory physiology & neurobiology·2025
Same author

Possible role of muscle AMP deamination.

American journal of physiology. Regulatory, integrative and comparative physiology·2025
Same author

Biochemical origin of (near-) linear curvature constant (W')- <math> </math> slow component ( <math></math> ) and critical power (CP)- <math> </math> transition time (t<sub>0.63</sub>) relationship in skeletal muscle.

European journal of applied physiology·2024

Related Experiment Video

Updated: Jul 14, 2026

Assessing Energy Substrate Oxidation In Vitro with 14CO2 Trapping
09:20

Assessing Energy Substrate Oxidation In Vitro with 14CO2 Trapping

Published on: March 23, 2022

Regulation of oxidative phosphorylation through parallel activation.

Bernard Korzeniewski1

  • 1Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, ul. Gronostajowa 7, 30-387 Kraków, Poland. benio@mol.uj.edu.pl

Biophysical Chemistry
|June 15, 2007
PubMed
Summary

Muscle contraction requires rapid ATP production. A new parallel activation mechanism, not just feedback signals, explains how oxidative phosphorylation meets energy demands during exercise.

More Related Videos

Oxygen-Independent Assays to Measure Mitochondrial Function in Mammals
05:59

Oxygen-Independent Assays to Measure Mitochondrial Function in Mammals

Published on: May 19, 2023

Simultaneous Measurement of Superoxide/Hydrogen Peroxide and NADH Production by Flavin-containing Mitochondrial Dehydrogenases
08:57

Simultaneous Measurement of Superoxide/Hydrogen Peroxide and NADH Production by Flavin-containing Mitochondrial Dehydrogenases

Published on: February 24, 2018

Related Experiment Videos

Last Updated: Jul 14, 2026

Assessing Energy Substrate Oxidation In Vitro with 14CO2 Trapping
09:20

Assessing Energy Substrate Oxidation In Vitro with 14CO2 Trapping

Published on: March 23, 2022

Oxygen-Independent Assays to Measure Mitochondrial Function in Mammals
05:59

Oxygen-Independent Assays to Measure Mitochondrial Function in Mammals

Published on: May 19, 2023

Simultaneous Measurement of Superoxide/Hydrogen Peroxide and NADH Production by Flavin-containing Mitochondrial Dehydrogenases
08:57

Simultaneous Measurement of Superoxide/Hydrogen Peroxide and NADH Production by Flavin-containing Mitochondrial Dehydrogenases

Published on: February 24, 2018

Area of Science:

  • Biochemistry
  • Exercise Physiology
  • Cellular Metabolism

Background:

  • Oxidative phosphorylation maintains cellular ATP levels during increased muscle work.
  • Traditional negative feedback regulation by ADP and Pi is insufficient to explain in vivo muscle energetics.
  • Calcium ions activate ATP usage and substrate dehydrogenation during muscle contraction.

Purpose of the Study:

  • To review and discuss evidence for the each-step-activation mechanism of oxidative phosphorylation.
  • To compare the each-step-activation mechanism with alternative models.
  • To identify the mechanism that best explains experimental data in intact skeletal muscle and heart.

Main Methods:

  • Theoretical analysis using a dynamic computer model of oxidative phosphorylation.
  • Review and critical discussion of existing experimental evidence.
  • Comparative analysis of proposed regulatory mechanisms.

Main Results:

  • The traditional feedback mechanism is kinetically insufficient for intact muscle.
  • A parallel activation (each-step-activation) mechanism is strongly suggested by dynamic modeling.
  • This mechanism involves direct activation of all oxidative phosphorylation complexes during muscle contraction.

Conclusions:

  • The each-step-activation mechanism provides a comprehensive explanation for experimental observations in muscle energetics.
  • It accounts for the rapid adjustments in ATP production needed during muscle activity.
  • This model offers a superior framework for understanding oxidative phosphorylation regulation in vivo compared to alternatives.