All flashcards
Flashcard 1: What is the primary function of enzymes in biological systems?
Answer: Catalysts that lower activation energy of reactions. They speed up reactions by reducing the energy barrier needed to start them.
Flashcard 2: Identify the term for enzyme helpers that are small organic molecules.
Answer: Coenzymes. Organic molecules like vitamins that assist in enzyme catalysis.
Flashcard 3: Identify the term for enzymes with multiple forms that catalyze the same reaction.
Answer: Isozymes. Different enzyme variants that perform the same catalytic function.
Flashcard 4: Identify the term for the protein component of an enzyme without its cofactor.
Answer: Apoenzyme. The protein part that needs cofactors to become fully functional.
Flashcard 5: Which enzyme catalyzes the breakdown of hydrogen peroxide?
Answer: Catalase. Converts toxic H2O2 into harmless water and oxygen.
Flashcard 6: What does 'substrate saturation' refer to in enzyme kinetics?
Answer: Point where increasing substrate does not increase rate. All enzyme active sites are occupied, creating maximum reaction rate.
Flashcard 7: What is the term for a reaction rate plateau despite increased substrate?
Answer: Saturation. Maximum rate reached when all enzymes are working at full capacity.
Flashcard 8: Which enzyme catalyzes the breakdown of hydrogen peroxide?
Answer: Catalase. Converts toxic H2O2 into harmless water and oxygen.
Flashcard 9: Identify the term for enzymes with multiple forms that catalyze the same reaction.
Answer: Isozymes. Different enzyme variants that perform the same catalytic function.
Flashcard 10: Identify the term for enzyme helpers that are small organic molecules.
Answer: Coenzymes. Organic molecules like vitamins that assist in enzyme catalysis.
Flashcard 11: What is the effect of temperature on enzyme activity?
Answer: Increases activity up to an optimal point; then decreases. Heat increases molecular motion but denatures enzymes at extreme temperatures.
Flashcard 12: What happens to enzyme activity when pH is altered from optimal?
Answer: Activity decreases. pH changes alter enzyme shape and charge distribution at the active site.
Flashcard 13: Define the term 'apoenzyme'.
Answer: Inactive enzyme lacking its cofactor. Requires cofactor binding to become catalytically active.
Flashcard 14: What is the term for a non-protein molecule aiding enzyme function?
Answer: Cofactor. Inorganic helper molecule essential for proper enzyme function.
Flashcard 15: What is the effect of temperature on enzyme activity?
Answer: Increases activity up to an optimal point; then decreases. Heat increases molecular motion but denatures enzymes at extreme temperatures.
Flashcard 16: Name an enzyme that breaks down starch into sugar.
Answer: Amylase. Breaks down starch into maltose and glucose for energy.
Flashcard 17: What is the primary structural unit of an enzyme?
Answer: Amino acids. Linked amino acids form the backbone of all enzyme structures.
Flashcard 18: Which term describes the enzyme's specificity to its substrate?
Answer: Lock and key model. Describes how enzyme shape perfectly matches its specific substrate.
Flashcard 19: Which term describes the specific 3D arrangement of an enzyme?
Answer: Conformation. 3D shape determines function and substrate binding specificity.
Flashcard 20: State the effect of a non-competitive inhibitor on enzyme activity.
Answer: Reduces activity regardless of substrate concentration. Binds to allosteric site, changing enzyme shape and reducing function.
Flashcard 21: Identify the hypothesis describing enzyme-induced fit with substrates.
Answer: Induced fit model. Enzyme slightly changes shape to better accommodate the substrate.
Flashcard 22: What is the result of enzyme denaturation?
Answer: Loss of structure and function. Heat or pH extremes unfold the protein, destroying active site shape.
Flashcard 23: What is the role of an allosteric site in enzyme regulation?
Answer: Site for non-competitive inhibitors or activators. Regulatory binding site separate from the active site.
Flashcard 24: What is the term for the minimum energy required to start a reaction?
Answer: Activation energy. Energy barrier that enzymes lower to speed up reactions.
Flashcard 25: What effect does enzyme concentration have on reaction rate?
Answer: Increases rate until substrate saturation. More enzymes mean more active sites until all substrate is bound.
Flashcard 26: Which term describes the enzyme-substrate complex transition state?
Answer: Transition state. High-energy intermediate formed during the enzyme-catalyzed reaction.
Flashcard 27: Which molecule acts as a common coenzyme in redox reactions?
Answer: NAD+. Essential electron carrier in cellular respiration and metabolism.
Flashcard 28: Which term describes enzymes that remain unchanged after a reaction?
Answer: Reusable. Enzymes are not consumed and can catalyze multiple reaction cycles.
Flashcard 29: Identify the term for a molecule that decreases enzyme activity.
Answer: Inhibitor. Reduces enzyme function through competitive or non-competitive mechanisms.
Flashcard 30: Identify the part of the enzyme where substrate molecules bind.
Answer: Active site. This binding region has a specific shape complementary to the substrate.