Metabolism: A Review

1
Metabolism A Review

• Dr. Clower
• Chem 4203

2
Some definitions

• Metabolism
• Metabolite
• Catabolism
• Anabolism
• Amphibolic
• Pathway

3
The amphibolic citric acid cycle
4
Regulation of metabolic pathways

• Feedback inhibition
• Feed-forward activation
• Covalent modification of enzyme
• Genetic control (regulate levels of enzyme)

5
Energy

• Flow
• Recovery
• Control

6
Energy, cont.

• ATP
• ADP
• AMP
• Pi
• PPi
• Phosphorylation
• High energy bond
• Kinase

7
Reactions in metabolic pathways

• Catalysis
• Types of reactions
• Coenzymes and cofactors
• Acetyl-CoA

8
Glycolysis
1
2
3

• How many stages/phases?
• How many reactions?
• What is the overall reaction?
• Where does regulation occur?
• What happens to the products of glycolysis?

4
5
6
7
8
9
10
(McKee and McKee, Biochemistry, 3rd ed.)
9
Fate of Pyruvate

• Pyruvate does not accumulate
• Undergoes one of 3 possible enzyme-catalyzed
  reactions
• Reaction depends on type of cell or species

10
The citric acid cycle

• How many reactions?
• What is the overall reaction?
• Where does regulation occur?
• What happens to the intermediates in the pathway?

11
Other carbohydrate pathways

• Non-glucose carbohydrates
• Pentose phosphate pathway
• Gluconeogenesis