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Citric Acid Cycle

Topic

  • Biochemistry & Molecular Biology
  • Macromolecules
  • Enzymes & Reactions
  • Cell Biology
  • Cellular Energetics

Resource Type

  • Videos
  • Animations

Level

High School — AP/IBCollege

Duration

00:06:10
Saved By
15 Users
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Description

This animation shows the reactions of the citric acid cycle, which splits off carbon atoms and generates energy-rich reduced forms of cofactor molecules. It is the third of six animations about cellular respiration. These animations bring to life the molecular engines inside mitochondria that generate ATP, the main source of chemically stored energy used throughout the body.
 
The citric acid cycle is a key component of cellular respiration. The citric acid cycle gains two carbon atoms from glycolysis (first animation), and those atoms are split off one by one to be released as carbon dioxide. The reactions release chemical energy, which is captured as energy-rich reduced forms of cofactors. These cofactors provide the chemical energy for the electron transport chain (fourth animation), which is the next stage of cellular respiration. The citric acid cycle also produces many intermediate molecules that are precursors to important biological molecules.
 
The animation is appropriate for teaching advanced high school or college-level students the in-depth mechanisms of the citric acid cycle. For more general audiences, the animation can be used as an example of molecular machines and enzymes in action. Depending on students’ background, it may be helpful to pause the animation at various points to discuss different reactions or molecules. 

All six cellular respiration animations are also available in a YouTube playlist.

An audio descriptive version of the film is available via our media player.

Key Terms

ATP, cell membrane, cellular respiration, chemical reaction, electron, energy, enzyme, metabolism, mitochondria, oxidation

Terms of Use

The resource is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International license. No rights are granted to use HHMI’s or BioInteractive’s names or logos independent from this Resource or in any derivative works.

Accessibility Level (WCAG compliance)

PDF files meet criteria. Video files meet criteria.

Version History

Date Published 10.02.20
Date Updated 03.10.23

NGSS (2013)

HS-LS1.C, HS-LS2.B

AP Biology (2019)

ENE-1, SP2

IB Biology (2016)

ENE-1, SP2

Vision and Change (2009)

CC2, CC4; DP3

Materials

Animation 1080P (M4V) 240 MB
Animation 1080P (WMV) 240 MB
Animation 720P (M4V) 99 MB
Animation 720P (WMV) 148 MB
Transcript (PDF) 189 KB

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