Microbiology, 2021

8.2 • Catabolism of Carbohydrates 295
Figure 8.9 (a) Binding of an allosteric inhibitor reduces enzyme activity, but binding of an allosteric activator increases enzyme activity. (b)
Feedback inhibition, where the end product of the pathway serves as a noncompetitive inhibitor to an enzyme early in the pathway, is an
important mechanism of allosteric regulation in cells.
CHECK YOUR UNDERSTANDING
• Explain the difference between a competitive inhibitor and a noncompetitive inhibitor.
8.2 Catabolism of Carbohydrates
Learning Objectives
By the end of this section, you will be able to:
• Describe why glycolysis is not oxygen dependent
• Define and describe the net yield of three-carbon molecules, ATP, and NADH from glycolysis
• Explain how three-carbon pyruvate molecules are converted into two-carbon acetyl groups that can be
funneled into the Krebs cycle.
• Define and describe the net yield of CO 2 , GTP/ATP, FADH 2 , and NADH from the Krebs cycle
• Explain how intermediate carbon molecules of the Krebs cycle can be used in a cell
Extensive enzyme pathways exist for breaking down carbohydrates to capture energy in ATP bonds. In