Environmental Impacts on Enzyme Function - AP Biology

1. What is the result of an enzyme being at its optimal pH?

   Maximum activity. Optimal ionization state for catalytic function.

2. Identify the effect of a coenzyme on enzyme function.

   Coenzymes act as carriers for atoms or functional groups. Organic cofactors that transport chemical groups.

3. What is the tertiary structure of an enzyme?

   Three-dimensional folding of a polypeptide. Overall 3D shape crucial for enzyme function.

4. Define the term 'allosteric site' on an enzyme.

   A site other than the active site for regulation. Regulatory binding site separate from catalytic center.

5. What is the inactive form of an enzyme without its cofactor?

   Apoenzyme. Protein component lacking required cofactors for activity.

6. Identify the primary structure of an enzyme.

   Amino acid sequence. Linear order of amino acids in the protein.

7. What is the term for the maximum rate of an enzyme-catalyzed reaction?

   $V_{max}$. Achieved when all enzyme active sites are occupied.

8. What is an enzyme's active site?

   The region where substrate molecules bind. Specific shape determines enzyme-substrate interaction.

9. What is feedback inhibition in enzyme activity?

   End product inhibits the pathway. Product accumulation prevents pathway overproduction.

10. What happens to enzyme activity at temperatures above the optimum?

    Enzyme activity decreases due to denaturation. Heat breaks bonds maintaining enzyme's 3D structure.

11. Identify the effect of substrate concentration on enzyme activity.

    Activity increases until the enzyme is saturated. More substrate means more enzyme-substrate collisions.

12. Identify the term for an enzyme's loss of shape and function.

    Denaturation. Loss of secondary and tertiary structure.

13. What is the lock-and-key model of enzyme activity?

    Substrate fits exactly into the active site. Rigid complementary shapes for substrate binding.

14. What is the effect of non-competitive inhibition on $V_{max}$?

    Decreases $V_{max}$. Allosteric binding reduces enzyme efficiency.

15. How does pH affect enzyme activity?

    Enzymes have an optimal pH range where they function best. pH changes affect ionization of active site amino acids.

16. What is the effect of enzyme inhibitors on metabolic pathways?

    They slow or stop the pathway. Block key enzymes, disrupting metabolic flow.

17. How does extreme pH cause enzyme denaturation?

    It disrupts ionic bonds and hydrogen bonds. Changes in charge distribution destabilize protein structure.

18. What is the effect of low temperatures on enzyme activity?

    Decreases activity by slowing molecular motion. Reduced kinetic energy decreases collision frequency.

19. What is the secondary structure of enzymes?

    Alpha helices and beta sheets. Regular folding patterns within protein chains.

20. What is the effect of a low substrate concentration on enzyme activity?

    Results in a lower reaction rate. Fewer substrate molecules limit enzyme-substrate formation.

21. What is the induced fit model of enzyme activity?

    Active site changes shape to fit the substrate. Dynamic conformational change upon substrate binding.

22. What is the role of an enzyme in a chemical reaction?

    Lowers activation energy. Stabilizes transition state, making reaction easier.

23. What is the active form of an enzyme called?

    Holoenzyme. Complete enzyme with all necessary cofactors attached.

24. Describe the effect of non-competitive inhibitors on enzymes.

    They reduce activity by altering enzyme shape. Bind elsewhere, changing enzyme conformation.

25. What effect does salinity have on enzyme activity?

    High salinity can denature enzymes. Disrupts water balance and protein stability.

26. What is the optimal temperature range for most human enzymes?

    35°C to 40°C. Body temperature range where enzyme structure remains stable.

27. How does competitive inhibition affect $K_m$?

    Increases $K_m$. Higher apparent affinity needed due to competition.

28. How does temperature affect the rate of enzyme activity?

    Increases until optimal, then decreases. Heat increases motion until denaturation occurs.

29. What is the effect of increasing enzyme concentration on reaction rate?

    Increases reaction rate until substrate is limited. More enzymes provide more active sites for reactions.

30. What role do cofactors play in enzyme activity?

    They assist enzymes in catalysis. Inorganic helpers required for proper enzyme function.

31. Identify the term for the energy needed to start a reaction.

    Activation energy. Minimum energy barrier for chemical reactions to proceed.

32. Identify the impact of heavy metals on enzyme activity.

    They can inhibit activity by binding to the enzyme. Metals disrupt protein structure and active sites.

33. What is the effect of a mutation on enzyme function?

    Can alter enzyme structure and activity. Changes amino acid sequence, potentially affecting structure.

34. What is the role of vitamins in enzyme activity?

    Vitamins often serve as coenzymes. Essential nutrients converted to active coenzymes.

35. How do enzymes increase the speed of reactions?

    By lowering the activation energy. Stabilize transition states to accelerate reactions.

36. What is the quaternary structure of enzymes?

    Multiple polypeptide chains forming a protein. Complex proteins with multiple subunits working together.

37. Identify the effect of enzyme concentration on $V_{max}$.

    Increases $V_{max}$. More enzymes allow higher maximum reaction rates.

38. What is the result of enzyme saturation?

    Maximum reaction rate is reached. All active sites occupied, no further rate increase.

39. What is enzyme specificity?

    Enzymes catalyze specific reactions. Shape complementarity determines which substrates bind.

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