Enzyme Control and Feedback Mechanisms

Enzyme

Protein that catalyzes biochemical reactions.

Temperature Effect

Higher temperature increases molecular collisions.

Denaturation

Loss of enzyme structure due to extreme conditions.

pH Impact

Affects charge of amino acids in enzymes.

Competitive Inhibitors

Resemble substrate, bind to active site.

Km

Michaelis constant, indicates substrate affinity.

Vmax

Maximum reaction rate of an enzyme.

AZT

Competitive inhibitor for reverse transcriptase in HIV.

Transition State Analogues

Mimic transition state for enzyme inhibition.

Oseltamivir

Blocks neuraminidase, used against influenza.

Catalytic Antibodies

Antibodies that mimic enzyme active sites.

Non-competitive Inhibitors

Bind elsewhere, do not affect Km.

Irreversible Inhibitors

Covalently bind, permanently inactivate enzymes.

Feedback Inhibition

End product inhibits earlier pathway enzymes.

Allosteric Enzymes

Change shape upon effector binding, altering activity.

Allosteric Effectors

Metabolites that modulate enzyme activity non-covalently.

Sigmoidal Kinetics

Characteristic curve of allosteric enzyme activity.

Concerted Model

All subunits change conformation simultaneously.

Sequential Model

Binding induces conformational changes in subunits.

Covalent Modification

Regulation via reversible chemical changes.

Phosphorylation

Addition of phosphate groups to regulate enzymes.

Proproteins

Inactive precursors activated by proteolytic cleavage.

Zymogens

Inactive digestive enzymes activated by cleavage.

Protein Kinases

Enzymes that add phosphate groups.

Protein Phosphatases

Enzymes that remove phosphate groups.

Regulatory Enzymes

Key enzymes controlling metabolic pathways.

Active Site

Region where substrate binds on enzyme.

Biochemical Pathways

Series of reactions catalyzed by enzymes.

M-M Kinetics

Michaelis-Menten kinetics describe enzyme activity.

Substrate Concentration

Influences reaction rate and enzyme activity.