Untitled Quiz
46 Questions
1 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the role of enzymes in relation to activation energy?

  • Enzymes decrease the activation energy of reactions. (correct)
  • Enzymes increase the activation energy required for reactions.
  • Enzymes permanently alter the energy of reactants.
  • Enzymes have no effect on the activation energy.

    • Which statement accurately describes the transition state in a chemical reaction?

  • The transition state is equivalent to the substrate complex.
  • The transition state has the highest potential energy during the reaction. (correct)
  • The transition state does not affect the reaction rate.
  • The transition state is the lowest energy configuration.

    • Which of the following best defines the rate-limiting step in a chemical reaction?

  • The step with the lowest energy barrier.
  • The step with the highest activation energy. (correct)
  • The step that forms the most stable intermediate.
  • The step that consumes the most amount of reactants.

    • How do enzymes achieve a decrease in activation energy?

    <p>By stabilizing the transition state through various interactions.</p> Signup and view all the answers

    Which intermediate forms when a substrate binds to an enzyme?

    <p>Substrate-enzyme complex (ES).</p> Signup and view all the answers

    What effect do enzymes have on the reaction coordinate diagram?

    <p>They reduce the height of the activation energy barrier.</p> Signup and view all the answers

    What characteristic is associated with a flexible reactant in an uncatalyzed unimolecular reaction?

    <p>Higher activation energy than rigid reactants.</p> Signup and view all the answers

    What describes the molecular arrangement in the transition state?

    <p>It has a single fixed configuration.</p> Signup and view all the answers

    What type of reaction does an oxidoreductase enzyme primarily catalyze?

    <p>Transfer of electrons</p> Signup and view all the answers

    Which enzyme class is involved in the cleavage of bonds by elimination, resulting in double bonds or rings?

    <p>Lyases</p> Signup and view all the answers

    Which type of reaction is catalyzed by hydrolases?

    <p>Hydrolysis reactions</p> Signup and view all the answers

    What defines the enzyme-substrate complex's function in enzymatic catalysis?

    <p>It facilitates the conversion of substrate into product.</p> Signup and view all the answers

    In the context of enzyme activity, which statement is true regarding the effect of enzymes on reaction free energy?

    <p>Enzymes have no effect on the free energy of the reaction.</p> Signup and view all the answers

    What is the primary role of isomerases in biochemical reactions?

    <p>They catalyze the formation of isomeric forms.</p> Signup and view all the answers

    Which of the following enzyme classes utilizes ATP or similar cofactors during condensation reactions?

    <p>Ligases</p> Signup and view all the answers

    Which of the following is a characteristic of enzymes regarding substrate selectivity?

    <p>Binding can occur without any chemical reaction taking place.</p> Signup and view all the answers

    Which term refers to the pocket on an enzyme where substrate binding and catalysis occur?

    <p>Active site</p> Signup and view all the answers

    What is the main function of transferases in biochemical reactions?

    <p>To facilitate group transfer between molecules.</p> Signup and view all the answers

    What characterizes irreversible inhibitors in relation to enzyme activity?

    <p>They permanently deactivate the enzyme.</p> Signup and view all the answers

    Which of the following statements is true regarding competitive inhibition?

    <p>It interferes with the binding of the substrate to the enzyme's active site.</p> Signup and view all the answers

    How does uncompetitive inhibition affect the enzyme kinetics?

    <p>It does not change Vmax but decreases KM.</p> Signup and view all the answers

    Which statement correctly describes mixed inhibition?

    <p>It can bind to both the enzyme and the enzyme-substrate complex, affecting both binding and catalytic function.</p> Signup and view all the answers

    In a Lineweaver-Burk plot representing competitive inhibition, where do the lines intersect?

    <p>At the y-axis.</p> Signup and view all the answers

    What happens to KM in the presence of uncompetitive inhibitors?

    <p>KM decreases.</p> Signup and view all the answers

    Which type of inhibition can be characterized by a decrease in Vmax with no change in KM/Vmax ratio?

    <p>Uncompetitive Inhibition</p> Signup and view all the answers

    Which inhibitor can act as a suicide inhibitor?

    <p>Irreversible inhibitor</p> Signup and view all the answers

    Which type of catalysis involves a transient covalent bond between the enzyme and the substrate?

    <p>Covalent catalysis</p> Signup and view all the answers

    What role do metal ions play in enzyme catalysis?

    <p>Stabilize negative charges</p> Signup and view all the answers

    Which amino acid groups are critical for covalent catalysis?

    <p>Amine, thiolate, and reactive serine</p> Signup and view all the answers

    What is the primary function of general acid-base catalysis in enzymes?

    <p>To donate and receive protons effectively</p> Signup and view all the answers

    In the context of enzymes, what is meant by 'acid-base catalysis'?

    <p>The transfer of protons between amino acids</p> Signup and view all the answers

    What distinguishes metal ion catalysis from other catalysis types?

    <p>Involvement of a metal ion bound to the enzyme</p> Signup and view all the answers

    Which of the following best describes the mechanism of chymotrypsin during digestion?

    <p>It breaks down proteins into small peptides using proteolytic activity</p> Signup and view all the answers

    Which statement about acid-base catalysis is correct?

    <p>It optimizes proton transfer within the enzyme's active site</p> Signup and view all the answers

    What does a nucleophile in the context of covalent catalysis typically refer to?

    <p>A reactive component such as serine or thiolate on the enzyme</p> Signup and view all the answers

    Which of the following best describes the role of protons in general acid-base catalysis?

    <p>They are optimized for effective transfer in the enzyme's active site</p> Signup and view all the answers

    Under which condition does the Michaelis-Menten equation simplify to V0 = Vmax?

    <p>[S] is significantly greater than Km</p> Signup and view all the answers

    What is a key characteristic of the Lineweaver-Burk plot?

    <p>It provides a linear representation of Michaelis-Menten data.</p> Signup and view all the answers

    What does the specificity constant kcat/Km measure?

    <p>The efficiency of the enzyme-substrate interaction</p> Signup and view all the answers

    Which of the following enzymes shows a kcat/Km ratio close to the diffusion-controlled limit?

    <p>Acetylcholinesterase with Acetylcholine</p> Signup and view all the answers

    What happens to the Km term when substrate concentration [S] is very high?

    <p>It becomes insignificant in the denominator.</p> Signup and view all the answers

    In which scenario does reaction velocity not depend on substrate concentration?

    <p>When [S] is incredibly high.</p> Signup and view all the answers

    Which statement is true regarding kcat and Km for different enzymes?

    <p>Different enzymes can have different Km and kcat values.</p> Signup and view all the answers

    What does a nonlinear Michaelis-Menten plot primarily help to determine?

    <p>The kinetic parameters Km and Vmax</p> Signup and view all the answers

    Which of the following equations represents first order kinetics?

    <p>V0 = Vmax[S]/Km</p> Signup and view all the answers

    What is the typical kcat/Km range for enzymes that are diffusion-controlled?

    <p>Between 10^8 and 10^9 M–1s–1</p> Signup and view all the answers

    More Like This

    Untitled Quiz
    6 questions

    Untitled Quiz

    AdoredHealing avatar
    AdoredHealing
    Untitled Quiz
    37 questions

    Untitled Quiz

    WellReceivedSquirrel7948 avatar
    WellReceivedSquirrel7948
    Untitled Quiz
    19 questions

    Untitled Quiz

    TalentedFantasy1640 avatar
    TalentedFantasy1640
    Untitled Quiz
    50 questions

    Untitled Quiz

    JoyousSulfur avatar
    JoyousSulfur
    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser