Clinical Biochemistry: Enzymes Lecture
20 Questions
0 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 is the main function of enzymes in biological systems?

  • To convert products back to substrates
  • To accelerate specific chemical reactions (correct)
  • To slow down chemical reactions
  • To consume substrates
  • What is the term for the molecule that an enzyme acts on?

  • Holoenzyme
  • Cofactor
  • Product
  • Substrate (correct)
  • What is the term for an enzyme without its nonprotein component?

  • Cofactor
  • Metallo-enzyme
  • Holoenzyme
  • Apoenzyme (correct)
  • What is the term for a nonprotein moiety, such as a metal ion, that is required for enzyme activity?

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

    Which of the following enzymes requires Zn2+ for its activity?

    <p>Carbonic anhydrase</p> Signup and view all the answers

    What is the term for an enzyme that requires a metal ion for its activity?

    <p>Metallo-enzyme</p> Signup and view all the answers

    What is the role of a coenzyme in an enzymatic reaction?

    <p>To transiently associate with the enzyme</p> Signup and view all the answers

    What is the function of a proenzyme?

    <p>To remain inactive until activated</p> Signup and view all the answers

    What is the energy barrier that separates reactants and products in a chemical reaction?

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

    How do enzymes lower the energy required for activation?

    <p>By forming a catalyst-substrate complex</p> Signup and view all the answers

    What is the purpose of the EC numbering system for enzymes?

    <p>To provide a systematic name for each enzyme</p> Signup and view all the answers

    Which class of enzymes catalyzes the oxidation of one substrate with simultaneous reduction of another substrate?

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

    Which enzyme is an example of a transferase?

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

    What is the result of the action of a hydrolase enzyme?

    <p>Breaking of a covalent bond</p> Signup and view all the answers

    What is the primary function of Lyases enzymes?

    <p>To remove groups from substrates by mechanisms other than hydrolysis</p> Signup and view all the answers

    What is the enzyme that catalyzes the breakdown of Acetylcholine into Choline and acetate?

    <p>Acetylcholine esterase</p> Signup and view all the answers

    Which class of enzymes is responsible for producing optical, geometric or positional isomers of substrates?

    <p>Class 5: Isomerases</p> Signup and view all the answers

    What is the reaction catalyzed by Aldolase enzyme?

    <p>Fructose-1,6-bisphosphate → Glyceraldehyde-3-phosphate + dihydroxy acetone phosphate</p> Signup and view all the answers

    Which class of enzymes is responsible for linking two substrates together, usually with the simultaneous hydrolysis of ATP?

    <p>Class 6: Ligases</p> Signup and view all the answers

    What is the enzyme that catalyzes the reaction: Glyceraldehyde-3-phosphate → Dihydroxy acetone phosphate?

    <p>Triose phosphate isomerase</p> Signup and view all the answers

    Study Notes

    Enzymes

    • Enzymes are biological catalysts produced by living tissues, which accelerate specific chemical reactions without being consumed in the process.
    • Most enzymes are proteins, except for a small group of RNA molecules that act as ribozymes.

    Substrate, Product, Cofactor, and Coenzyme

    • Substrate: the molecule that an enzyme acts on
    • Product: the molecule that an enzyme converts the substrate into
    • Cofactor: a non-protein moiety that can be a metal ion (e.g., Zn2+ or Fe2+) or a small organic molecule
    • Coenzyme: a non-protein moiety that is a small organic molecule
    • Holoenzyme: the active enzyme with its non-protein component (cofactor or coenzyme)
    • Apoenzyme: the enzyme without its non-protein moiety, which is inactive

    Types of Cofactors and Coenzymes

    • Metallo-enzymes: enzymes that require certain metal ions for their activity (e.g., zinc for Carbonic anhydrase and iron for Cytochrome oxidase)
    • Cosubstrate: a coenzyme that only transiently associates with the enzyme and dissociates from the enzyme in an altered state (e.g., NAD+)
    • Prosthetic group: a coenzyme that is permanently associated with the enzyme (e.g., FAD)

    Proenzymes (Zymogens)

    • Inactive enzymes found in the blood or digestive tract, which become activated by other enzymes (e.g., chymotrypsinogen is activated by trypsin to form chymotrypsin)

    Mechanism of Enzyme Action

    • Enzymes lower the energy required for activation to the transition state, allowing chemical reactions to occur at normal physiological temperatures

    Nomenclature of Enzymes

    • The International Union of Biochemistry and Molecular Biology (IUBMB) suggests a system of nomenclature for enzymes, with a name starting with EC (enzyme class) followed by 4 digits (e.g., EC.1.1.1.1)

    Classification of Enzymes

    • Class 1: Oxidoreductases (e.g., Lactate dehydrogenase)
    • Class 2: Transferases (e.g., Hexokinase)
    • Class 3: Hydrolases (e.g., Acetylcholine esterase)
    • Class 4: Lyases (e.g., Aldolase)
    • Class 5: Isomerases (e.g., Triose phosphate isomerase)
    • Class 6: Ligases (e.g., Acetyl CoA carboxylase)

    Studying That Suits You

    Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

    Quiz Team

    Description

    This quiz covers the basics of enzymes, including definitions, substrates, and products, as part of a clinical biochemistry course.

    More Like This

    Enzymes in Clinical Biochemistry
    5 questions

    Enzymes in Clinical Biochemistry

    HumorousAntigorite9345 avatar
    HumorousAntigorite9345
    Biochemistry Chapter: Enzyme Function
    40 questions
    Use Quizgecko on...
    Browser
    Browser