7 - Lecture notes 7.4 PDF

Preview

Summary

Biology 95 - 3002
Mon/Wed Class 4:30pm – 5:50pm
Valella...

Description

7.4 – Second Stage of Aerobic Respiration  The second stage of aerobic respiration finishes the breakdown of glucose that began in glycolysis.  Links to Mitochondria 4.9, Cyclic pathways 5.5 Page 113

Krebs Cycle

Cyclic pathway that, along with acetylCoA formation, breaks down pyruvate to carbon dioxide. The second stage of aerobic respiration occurs inside mitochondria. It includes two sets of reactions, acetyl-CoA formation and the Krebs cycle, that break down pyruvate, the product of glycolysis. All of the carbon atoms that were once part of glucose end up in CO2, which departs the cell. Only two ATP form. The big payoff: the formation of many reduced coenzymes that drive the third and final stage of aerobic respiration.

Take-Home Message What happens during the second stage of aerobic respiration? The second stage of aerobic respiration, acetyl–CoA formation and the Krebs cycle, occurs in the inner compartment (matrix) of mitochondria. The pyruvate that formed in glycolysis is converted to acetyl–CoA and carbon dioxide. The acetyl–CoA enters the Krebs cycle, which breaks it down to CO2. For each two pyruvate molecules broken down in the second-stage reactions, two ATP form, and ten coenzymes (eight NAD+ and two FAD) are reduced....