Enzymes: Biochemistry 1 Code (4125) Learning Objectives

Enzyme Inhibitors

• Competitive inhibitors compete with the substrate for the enzyme's active site, blocking the substrate from binding.
• Noncompetitive inhibitors bind to a location away from the active site, leading to conformational changes that reduce enzyme activity.
• Noncompetitive inhibition mechanism involves reducing the maximum rate of reaction (Vmax) without affecting the affinity of the enzyme for the substrate (Km remains unchanged).
• Irreversible inhibitors permanently bind to the enzyme, often leading to a loss of enzyme activity because they modify the active site.
• Allosteric inhibitors can bind to sites other than the active site, regulating enzyme activity through conformational changes.

Enzyme Activity and Regulation

• Feedback inhibitors can repress the gene coding for an enzyme or directly inhibit the enzyme itself, thereby blocking a biosynthetic pathway.
• Clinical significance of plasma enzymes is indicated by a heightened rate of release from tissues, commonly assessed in diagnostic tests.
• The primary effect of enzyme inhibition is to decrease the rate of product formation within a biochemical pathway.

Specificity and Range of Inhibition

• Specific inhibitors target only one enzyme or a small group, allowing for precise control in metabolic processes.
• Broad-spectrum inhibitors can affect a wide range of enzymes, potentially impacting multiple pathways simultaneously.
• The binding of a substrate to an active site typically leads to an enzyme-substrate complex formation, which is essential for catalyzing the conversion of substrates to products.

Test your knowledge of enzyme inhibition, clinical significance of enzymes, and normal enzyme reactions. Understand how a substrate binds to an enzyme, forming an enzyme-substrate complex, and how the induced fit model affects chemical bonds within the substrate.