In this lesson you will learn about the Citric Acid Cycle (CAC) and Oxidative Phosphorylation, the other two stages of cellular respiration.
By the end of this lesson, students should be able to:
- link Glycolysis to the Citric Acid Cycle using the oxidation of Pyruvate.
- describe in detail how pyruvate is converted to Acetyl CoA and how it enter the mitochondrial matrix.
- describe the joining of Acetyl CoA and Oxaloacetate leading to the formation of Citric Acid (the first step of CAC)
- identify the products of the subsequent seven reactions of the CAC as well as the names of the enzymes involved in each step.
- list the major products of the CAC per each turn. That is the number of ATP, NADH and FADH2 molecules produced per turn and per glucose molecule that gets oxidized.
- Describe the pathway of electron transport from the reducing power molecules NADH and FADH2 to molecular oxygen as the final electron acceptor.
- know the names of the protein complexes and electron carriers in the electron transport chain (ETC).
- Explain how a proton gradient is created between the mitochondrial matrix and the intermembrane space (the proton motive force).
- explain in detail how ATP synthase harnesses the proton-motive force to phosphorylate ADP.
- compare and contrast aerobic respiration (cellular respiration) to anaerobic respiration (fermentation)
- explain the two types of fermentation: alcohol fermentation and lactic acid fermentation
- distinguish between obligate and facultative anaerobes
To begin, let’s examine in detail the CAC. Please take notes as you watch the video lesson below.
The Citric Acid Cycle Activity
Learning goal: To describe in detail and in sequence from the moment Acetyl-CoA enters the Citric Acid cycle up to the regeneration of Oxaloacetate.
Your job: To watch the animation below and then produce a flow chart describing the eight (8) steps of the Citric Acid cycle.
The last stage of cellular respiration, oxidative phosphorylation, and fermentation are introduced in the video lesson below. Once again, please take notes as you watch the video lesson below.
Below is a poster/study note on the Citric Acid Cycle (a.k.a. Kreb’s cycle) Note that this poster shows up 9 reactions instead of the 8 explained in the video lesson. For teaching purposes only 8 reactions are to be learned.
Below is a study note/poster on Oxidative Phosphorylation. Please print it out and use it to prepare for a test.
Oxidative Phosphorylation Activity
Learning goal: To describe in detail both the two phases of the oxidative phosphorylation process: The Electron Transport Chain and Chemiosmosis with emphasis on the production of ATP and H2O
Your job: To watch the animation below and then produce a flow chart describing the flow of electrons through the Electron Transport Chain (ETC) and the formation of ATP.
An accounting of ATP production by cellular respiration and Fermentation are shown in the posters/study notes below. Print them out to study and prepare for an upcoming test.