4 - ENZYMES HUHUHUHU

• What is an enzyme?

  Protein specialized to catalyze metabolic reactions
• How do enzymes affect biochemical reaction rates?

  They accelerate and control reaction rates
• What is a catalyst?

  Substance that increases reaction rate without consumption
• What is a substrate?

  Reacting molecule upon which an enzyme acts
• What is a product in enzymatic reactions?

  Substance formed from enzyme and substrate reaction
• What is an apoenzyme?

  Protein portion of an enzyme, inactive without cofactor
• What is a cofactor?

  Non-protein component required for enzyme activity
• What is a holoenzyme?

  Active enzyme consisting of apoenzyme and cofactor
• What is a transition-state complex?

  Temporary structure resembling substrates and products
• What is activation energy?

  Minimum energy required to reach transition state
• What is a competitive inhibitor?

  Molecule resembling substrate that competes for active site
• How does a noncompetitive inhibitor affect enzyme activity?

  It alters enzyme activity without competing with substrate
• What does amylase do?

  Hydrolyzes starch into sugars
• Where is salivary amylase produced?

  In saliva
• What does catalase do?

  Decomposes hydrogen peroxide into water and oxygen
• What is the role of catecholase?

  Oxidizes catechols to o-quinones
• What is papain?

  Proteolytic enzyme from papaya that breaks down proteins
• What does invertase do?

  Hydrolyzes sucrose into glucose and fructose
• What does pectinase do?

  Breaks down pectin in plant cell walls
• What is pepsin?

  Digestive enzyme that breaks proteins into peptides
• What does rennin do?

  Coagulates milk protein casein
• What is the function of lactase?

  Breaks down lactose into glucose and galactose
• What does lipase do?

  Hydrolyzes fats into fatty acids and glycerol
• What is the role of DNA polymerase?

  Synthesizes DNA molecules during replication
• What does RNA polymerase do?

  Synthesizes RNA from a DNA template
• What is the function of adenylate cyclase?

  Converts ATP to cyclic AMP
• What is the role of nitrate reductase?

  Reduces nitrate to nitrite in plants
• What does glutamate dehydrogenase catalyze?

  Reversible reaction between glutamate and α-ketoglutarate
• What is the function of carbonic anhydrase?

  Converts CO₂ and water to bicarbonate and protons
• What does cholesterol esterase do?

  Hydrolyzes cholesterol esters into cholesterol
• What does alcohol dehydrogenase do?

  Converts ethanol to acetaldehyde
• What is catalytic power?

  Ratio of enzyme-catalyzed to uncatalyzed reaction rate
• What does specificity refer to in enzymes?

  Selectivity of an enzyme for its substrate
• What is enzyme regulation?

  Control of enzyme activity to match cellular needs
• What is enzyme nomenclature?

  System of naming enzymes, often with “-ase”
• What is a coenzyme?

  Organic cofactor required for enzyme activity
• What is a prosthetic group?

  Tightly bound coenzyme essential for enzyme function
• What is kinetics in enzymology?

  Study of reaction rates and enzyme catalysis
• What is chemical kinetics?

  Branch of chemistry studying rates of chemical reactions
• What is an active site?

  Specific region where substrate binds and reaction occurs