Page 70 - General Biochemistry

Levels of Metabolism Regulation
1. Nervous system.
2. Endocrine system.
3. Interaction between organs.
4. Cell (membrane) level.
5. Molecular level
Feedback inhibition
Product of a pathway controls the rate of its own synthesis by inhibiting an

early step (usually the first “committed” step (unique to the pathway)

Feed-forward activation
Metabolite early in the pathway activates an enzyme further down the pathway

Covalent modification for enzyme regulation
• Interconvertible enzyme activity can be rapidly and reversibly altered by

covalent modification
• Protein kinases phosphorylate enzymes (+ ATP)
• Protein phosphatases remove phosphoryl groups

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