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Biology LibreTexts

7.4A: Mitochondria

Skills to Develop

  1. Briefly describe mitochondria and state their function.
  2. State where in the mitochondria the electron transport chain is located.
  3. State where in the mitochondria the enzymes for the citric acid cycle (Krebs cycle) are located.

Mitochondria are rod-shaped structures ranging from 2 to 8 micrometers in length. They are found throughout the cytoplasm and may account for up to 20% of the cell's volume. Mitochondria are surrounded by two membranes. The outer membrane forms the exterior of the organelle while the inner membrane is arranged in a series of folds called cristae to provide an enormous surface area for chemical reactions. The space between the inner and outer mitochondrial membranes is called the intermembrane space while the compartment enclosed by the inner mitochondrial membrane is called the matrix. Mitochondria replicate giving rise to new mitochondria as they grow and divide. They also have their own DNA and ribosomes.

Figure 4.1.1: Two mitochondria from mammalian lung tissue displaying their matrix and membranes as shown by electron microscopy. Image used with permission from  Louisa Howard (public domain.

Mitochondria function during aerobic respiration to produce ATP through oxidative phosphorylation. The respiratory enzymes and electron carriers for the electron transport system are located within the inner mitochondria membrane. The enzymes for the citric acid cycle (Krebs cycle) are located in the matrix.

 

Concept map for Eukaryotic Cell Structure

Summary

  1. Mitochondria are rod-shaped structures ranging from 2 to 8 micrometers in length surrounded by two membranes.
  2. Mitochondria are located throughout the cytoplasm.
  3. Mitochondria function during aerobic respiration to produce ATP through oxidative phosphorylation.
  4. The respiratory enzymes and electron carriers for the electron transport system are located within the inner mitochondria membrane. The enzymes for the citric acid cycle (Krebs cycle) are located in the matrix.
  5. Mitochondria replicate giving rise to new mitochondria as they grow and divide. They also have their own DNA and ribosomes.

Questions

Study the material in this section and then write out the answers to these questions. Do not just click on the answers and write them out. This will not test your understanding of this tutorial.

  1. Briefly describe mitochondria and state their function.
  2. State where in the mitochondria the electron transport chain is located.
  3. State where in the mitochondria the enzymes for the citric acid cycle (Krebs cycle) are located.

Contributors

  • Dr. Gary Kaiser (COMMUNITY COLLEGE OF BALTIMORE COUNTY, CATONSVILLE CAMPUS)