foundation of nursing ngt

Enzymes Biochemistry

Definition and Function

• Biological molecules that catalyze chemical reactions
• Increase reaction rates without being consumed by the reaction
• Highly specific to substrate molecules

Characteristics

• Protein structure: Most enzymes are proteins, composed of amino acids
• Active site: Region on the enzyme surface where substrate binding occurs
• Optimal pH and temperature: Enzymes have specific pH and temperature ranges for optimal activity
• Cofactors and coenzymes: Some enzymes require additional molecules to function

Mechanisms of Action

• Lock and key model: Enzyme active site complements substrate shape
• Induced fit model: Enzyme active site changes shape to fit substrate
• Acid-base catalysis: Enzyme uses acidic or basic residues to facilitate reaction
• Covalent catalysis: Enzyme forms a temporary covalent bond with substrate

Types of Enzymes

• Oxidoreductases: Catalyze oxidation and reduction reactions
• Transferases: Catalyze transfer of functional groups
• Hydrolases: Catalyze hydrolysis reactions
• Ligases: Catalyze formation of new covalent bonds
• Isomerases: Catalyze isomerization reactions
• Lyases: Catalyze cleavage of various chemical bonds

Enzyme Regulation

• Allosteric regulation: Binding of molecules to enzyme affects activity
• Feedback inhibition: Product of a reaction inhibits an earlier step in the pathway
• Substrate inhibition: High substrate concentrations inhibit enzyme activity
• Cooperative binding: Binding of multiple substrate molecules affects enzyme activity

Clinical Significance

• Enzyme deficiencies: Genetic disorders resulting from enzyme deficiencies
• Enzyme inhibitors: Medications that inhibit specific enzymes
• Enzyme assays: Laboratory tests to measure enzyme activity