Bioenergetics Unit 2 Quiz
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Questions and Answers

What is defined as the study of energy transfer in biological systems?

  • Bioenergetics (correct)
  • Metabolism
  • Catalysis
  • Thermodynamics

    • Which of the following best describes catabolism?

  • Synthesis of biomolecules using energy
  • Utilization of energy to perform work
  • Processes that maintain cellular order
  • Reactions that break down large biomolecules to release energy (correct)

    • What does the First Law of Thermodynamics state?

  • Spontaneous processes require external energy input
  • Natural processes are maintenance of order
  • Energy can be created or destroyed in a closed system
  • Energy can only be converted from one type to another (correct)

    • Which statement correctly reflects the Second Law of Thermodynamics?

    <p>Spontaneous processes increase the state of disorder</p> Signup and view all the answers

    What is the role of energy in maintaining cellular order?

    <p>Energy is required to decrease entropy</p> Signup and view all the answers

    What characterizes an endergonic reaction?

    <p>It requires input energy to proceed.</p> Signup and view all the answers

    How is energy captured for use in endergonic reactions?

    <p>As high-energy electrons on nucleotides.</p> Signup and view all the answers

    What does the equilibrium constant (Keq) indicate about a reversible reaction?

    <p>The ratio of products to substrates at equilibrium.</p> Signup and view all the answers

    What role does the net free energy change (∆G) play in reaction reversibility?

    <p>It indicates whether a reaction can proceed in the reverse direction.</p> Signup and view all the answers

    High negative ∆G reactions typically require what for the reverse reaction?

    <p>Significant energy input.</p> Signup and view all the answers

    What is the primary fuel source used by the body during moderate to high-intensity muscular effort?

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

    How much energy can protein provide for cellular activity?

    <p>10-15%</p> Signup and view all the answers

    Which statement accurately describes ATP hydrolysis?

    <p>It provides energy, releasing 7.3 kcal/mol.</p> Signup and view all the answers

    What regulates metabolism in relation to ATP?

    <p>The ratio of ATP to ADP</p> Signup and view all the answers

    What characterizes the ATP – PCr energy system?

    <p>It supplies ATP immediately at a high rate.</p> Signup and view all the answers

    What is the primary role of ATP in the cell?

    <p>Powering muscle contractions and cellular work</p> Signup and view all the answers

    What is the main characteristic of the Glycolytic System?

    <p>Operates in the absence of oxygen</p> Signup and view all the answers

    What is the consequence of ATP turnover rates in a cell?

    <p>They need to match rates of ATP production.</p> Signup and view all the answers

    What is the primary function of phosphocreatine (PCr) in energy metabolism?

    <p>Replenishes ATP during recovery</p> Signup and view all the answers

    Which of the following regulates the flow of molecules through metabolic pathways?

    <p>Maintaining a constant ratio of ATP-to-ADP</p> Signup and view all the answers

    What is the primary energy source utilized during the phosphagen system?

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

    How long does it generally take for full recovery of phosphocreatine (PCr) after exercise?

    <p>2-4 minutes</p> Signup and view all the answers

    What happens to the levels of ATP immediately after the start of exercise?

    <p>ATP levels remain constant</p> Signup and view all the answers

    Which enzyme is primarily involved in the reaction between phosphocreatine and ADP?

    <p>Creatine Kinase</p> Signup and view all the answers

    What is the outcome of the CK reaction and ATP hydrolysis at the sarcomere?

    <p>Decrease in phosphocreatine concentration</p> Signup and view all the answers

    What does EPOC stand for, and how is it related to ATP replenishment?

    <p>Excess Post-Exercise Oxygen Consumption</p> Signup and view all the answers

    What is the primary role of AMP in relation to enzyme activity during energy requirements?

    <p>Activates glycogen phosphorylase kinase</p> Signup and view all the answers

    What does a high KM value indicate about an enzyme or transporter?

    <p>Low affinity for substrate</p> Signup and view all the answers

    Which glucose transporter is known for being insulin-responsive?

    <p>GLUT 4</p> Signup and view all the answers

    Which of the following statements about Vmax is true?

    <p>Vmax can only be achieved at high substrate concentrations</p> Signup and view all the answers

    Where does the adenylate kinase reaction primarily occur?

    <p>In the cytosol</p> Signup and view all the answers

    When is the adenylate kinase reaction most likely to occur?

    <p>As energy requirements increase</p> Signup and view all the answers

    Which glucose transporter exhibits very high affinity for glucose?

    <p>GLUT 3</p> Signup and view all the answers

    What characterizes GLUT 2 among glucose transporters?

    <p>Bi-directional transport</p> Signup and view all the answers

    Study Notes

    Bioenergetics Overview

    • Study of energy transfer in biological systems, covering metabolism involving catabolism (energy-releasing reactions) and anabolism (energy-utilizing reactions).
    • Cells perform reactions to maintain energy balance and facilitate biological functions.

    Thermodynamics Principles

    • First Law: Energy in a closed system is constant—energy cannot be created or destroyed, only transformed.
    • Second Law: Spontaneous processes tend toward disorder (entropy) which requires energy to maintain order (endergonic reactions).

    Energy Concepts

    • Energy: Capacity to do work; work defined as force applied over a distance.
    • Power: Rate of doing work (work/time).
    • Body performance depends on energy conversion.

    Glucose Metabolism

    • Metabolic reactions can be exergonic (release energy) or endergonic (require energy), often coupled to fulfill energy requirements.
    • High-energy electrons are stored as NADH and FADH2 for later energy use.

    Reversible Reactions

    • Many cellular reactions are reversible and reach equilibrium defined by the ratio of products to substrates.
    • Reactions move towards equilibrium based on ΔG, where a negative ΔG indicates favoring products.

    Fuel Utilization

    • At rest: Body uses carbohydrates (CHO) and lipids for energy.
    • During exertion: CHO becomes the primary fuel source; lipids are more important during prolonged low-intensity activities.
    • Protein contributes up to 10-15% of energy and serves structural roles.

    ATP: Energy Currency

    • ATP (adenosine triphosphate) has high-energy phosphate bonds, mainly hydrolyzed to release energy (ΔG = -7.3 kcal/mol).
    • ATP homeostasis is crucial for muscle contraction and cellular work, requiring regulation of ATP production and turnover.

    Energy Pathways

    • Three main systems to maintain ATP levels:
      • ATP-PCr System: Immediate energy supply; high rate but low capacity.
      • Glycolytic System: Intermediate rate and capacity; non-oxidative, supports aerobic metabolism.
      • Oxidative System: Slower rate, very high ATP capacity.

    Metabolism Regulation

    • Flow of energy in metabolic pathways is managed by controlling enzyme concentration, producing allosteric modulators, isolating enzymes, and maintaining ATP/ADP ratios.

    Phosphagen System

    • Utilizes phosphocreatine (PCr) for rapid ATP production near muscle fibers.
    • Phosphocreatine levels drop during activity while ATP remains stable; recovery of PCr occurs quickly post-exercise.

    Adenylate Kinase Reaction

    • Converts ADP into ATP and AMP, indicating increased energy demand; AMP signals enhanced glycolysis activity through enzyme activation.

    Glycolysis and Lactate Production

    • Glycolysis converts glucose to pyruvate, yielding energy. Lactate accumulation can occur, especially during intense muscular activity without oxygen.

    Glucose Transport

    • Transporters (GLUT 1, GLUT 2, GLUT 3, GLUT 4, GLUT 5) facilitate glucose uptake, each with specific locations and affinities for glucose.
    • Vmax indicates maximum reaction velocity; KM represents substrate concentration at which half Vmax is achieved, reflecting enzyme affinity.

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    Related Documents

    Bioenergetics Lecture Notes PDF

    Description

    Test your knowledge on bioenergetics in this Unit 2 quiz. Explore topics including biological energy transfer, metabolic pathways, and the roles of enzymes and substrates. This quiz will help reinforce your understanding of ATP, glycolysis, lipid metabolism, and more.

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