Enzymatic Reaction Kinetics and Regulation Quiz
60 Questions
3 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What type of molecules are enzymes?

  • Protein molecules (correct)
  • Lipid molecules
  • RNA molecules
  • Carbohydrate molecules

    • What is the function of enzymes in cellular activity?

  • Maintaining temperature
  • Speeding up chemical reactions (correct)
  • Regulation of pH
  • Stabilizing hormones

    • What is the main characteristic of enzymes in relation to their substrates?

  • They have no effect on substrates
  • They have high specificity (correct)
  • They have low specificity
  • They form covalent bonds with substrates

    • Under what conditions do enzymes function?

    <p>Aqueous solutions under mild conditions of temperature and pH</p> Signup and view all the answers

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

    <p>To increase the speed of the reaction without suffering changes</p> Signup and view all the answers

    What is the specific molecular environment provided by enzymes for chemical reactions?

    <p>An energetically favorable environment</p> Signup and view all the answers

    What is the main factor that the Gibbs Free Energy (∆Go) depends on?

    <p>The final state</p> Signup and view all the answers

    In which type of reaction does the free-energy change (∆G) have a negative value?

    <p>Exergonic reaction</p> Signup and view all the answers

    In which type of reaction do the products contain more free energy than the reactants?

    <p>Endergonic reaction</p> Signup and view all the answers

    What happens to the reaction when ∆G is large and negative?

    <p>The reaction tends to go in the forward direction</p> Signup and view all the answers

    In competitive inhibition, how does the intercept on the plot of 1/V versus 1/[S] change in the presence of inhibitor?

    <p>It remains the same</p> Signup and view all the answers

    What is the energy that cells can and must use, described by the Gibbs free-energy function G?

    <p>Free energy</p> Signup and view all the answers

    What is the main effect of noncompetitive inhibition on Vmax and the intercept on the vertical axis?

    <p>Vmax decreases, intercept increases</p> Signup and view all the answers

    What is the main function of the Michaelis-Menten model in enzymatic reactions?

    <p>To measure the rate of enzyme activity</p> Signup and view all the answers

    Which type of inhibition cannot be overcome by increasing the concentration of substrate?

    <p>Reversible noncompetitive inhibition</p> Signup and view all the answers

    What does Km represent in the Michaelis-Menten equation?

    <p>The enzyme's affinity for the substrate</p> Signup and view all the answers

    What is the characteristic feature of irreversible inhibitors?

    <p>They chemically modify the enzyme and tightly bind to it</p> Signup and view all the answers

    What does Vmax indicate in enzymatic reactions?

    <p>The concentration of active sites in fully saturated enzymes</p> Signup and view all the answers

    What is the role of modulators in allosteric enzymes?

    <p>They regulate enzyme activity by binding to a different site than the active site</p> Signup and view all the answers

    What does a large and negative ∆G value indicate for a chemical reaction under standard conditions?

    <p>The reaction proceeds spontaneously</p> Signup and view all the answers

    What is the effect of competitive inhibitors on Km and Vmax?

    <p>$K_m$ increases, $V_{max}$ decreases</p> Signup and view all the answers

    What does a large and positive ∆G value indicate for a chemical reaction?

    <p>The products contain more free energy than the reactants</p> Signup and view all the answers

    Which type of inhibition involves simultaneous binding of inhibitor and substrate to the enzyme?

    <p>$Noncompetitive$ inhibition</p> Signup and view all the answers

    What is unique for each enzyme and inversely proportional to its affinity for the substrate?

    <p>Km value</p> Signup and view all the answers

    What is a characteristic feature of reversible competitive inhibitors?

    <p>$K_m$ increases, $V_{max}$ does not change</p> Signup and view all the answers

    In what conditions does Vmax occur during an enzymatically catalyzed reaction?

    <p>When all active sites are occupied by substrate molecules</p> Signup and view all the answers

    What distinguishes allosteric enzymes from Michaelis-Menten enzymes?

    <p>$Allosteric$ enzymes do not follow Michaelis-Menten kinetics</p> Signup and view all the answers

    In noncompetitive inhibition, what happens to Km and Vmax?

    <p>Km decreases, Vmax increases</p> Signup and view all the answers

    Which type of inhibitors competitively bind to allosteric sites instead of active sites?

    <p>Noncompetitive inhibitors</p> Signup and view all the answers

    Which type of NSAID inhibits only COX-2?

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

    What is the function of COX-1 according to the widely held belief?

    <p>Produces homeostatic PGs</p> Signup and view all the answers

    Which type of pain directly results from a lesion in nerves and the somatosensory system?

    <p>Neuropathic pain</p> Signup and view all the answers

    What is the primary function of NSAIDs?

    <p>Analgesic and anti-inflammatory</p> Signup and view all the answers

    Which NSAID is classified as a non-selective inhibitor of COX?

    <p>Diclofenac sodium</p> Signup and view all the answers

    What is the main effect of selective NSAIDs?

    <p>Inhibiting only COX-2</p> Signup and view all the answers

    Which type of NSAID is known for its antipyretic action?

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

    What is the primary source of belief regarding the production of PGs by COX-1 and COX-2?

    <p>&quot;Widely held&quot; belief</p> Signup and view all the answers

    Which type of pain affects structures in the mouth, such as gingival and subgingival tissue?

    <p>&quot;Somatic&quot; pain</p> Signup and view all the answers

    "Arthrotec" is a combination of which two compounds known for inhibiting COX?

    <p>&quot;Diclofenac sodium&quot; and &quot;Misoprostol&quot;</p> Signup and view all the answers

    Which type of amino acids in the active site directly participate in the chemical reaction?

    <p>Catalytic amino acids</p> Signup and view all the answers

    What type of molecules are holoenzymes?

    <p>Non-protein portion</p> Signup and view all the answers

    What is the region in the enzyme molecule where the enzymatic catalysis takes place?

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

    What do coenzymes provide during the enzymatic process?

    <p>Energy and electrons</p> Signup and view all the answers

    What is the essence of catalysis in enzymatic reactions?

    <p>Decrease in activation energy</p> Signup and view all the answers

    What is the energy derived from enzyme-substrate interactions called?

    <p>Binding energy</p> Signup and view all the answers

    What determines the speed of a chemical reaction according to the text?

    <p>$\Delta G^\ddagger$ (Activation energy)</p> Signup and view all the answers

    What is the transition state in a chemical reaction?

    <p>$S^\ddagger$</p> Signup and view all the answers

    What does the ground state represent in a reaction coordination diagram?

    <p>$S \rightarrow P$</p> Signup and view all the answers

    What is the function of coenzymes in enzymatic reactions?

    <p>To facilitate the catalysis by being non-covalently bound to the enzyme</p> Signup and view all the answers

    What is the main function of vitamin C (ascorbic acid) in enzymatic reactions?

    <p>Avoids oxidation of other vitamins</p> Signup and view all the answers

    What do transferases do in enzymatic reactions?

    <p>Transfer a chemical group to another molecule</p> Signup and view all the answers

    What is the characteristic of hydrolases in enzymatic reactions?

    <p>Special type of transferases that transfer a OH from water to another substrate</p> Signup and view all the answers

    What is the role of cyclooxigenase (COX) in enzymatic reactions?

    <p>Catalyze the first step in the synthesis of prostaglandins (PGs) from arachidonic acid</p> Signup and view all the answers

    What is the primary function of COX-1 according to its distribution and expression?

    <p>Widely distributed and constitutively expressed in most tissues</p> Signup and view all the answers

    What is the effect of pH on enzymes in enzymatic reactions?

    <p>Acts as a denaturing agent of proteins and thus to enzymes</p> Signup and view all the answers

    What is the role of ligases in enzymatic reactions?

    <p>Catalyze the formation of carbon-carbon bonds, requiring ATP energy</p> Signup and view all the answers

    What do isomerases catalyze in enzymatic reactions?

    <p>(Isomerases) Catalyze the movement of a group or double bond within a molecule producing a new isomer</p> Signup and view all the answers

    What do oxidoreductases catalyze in enzymatic reactions?

    <p>Catalyze addition or removal of groups to double bonds; formation of double bonds by removal of groups</p> Signup and view all the answers

    What is the main function of metal ions as cofactors in enzymatic reactions?

    <p>To participate in diverse functions such as oxidation-reduction and promoting hydrolysis</p> Signup and view all the answers

    What type of reaction do hydrolases catalyze in enzymatic reactions?

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

    More Like This

    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser