Chemistry: Covalent and Noncovalent Bonds
40 Questions
1 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 strongest force that holds molecules together?

  • Covalent bond (correct)
  • Electrostatic interactions
  • Hydrophobic interactions
  • Van der Waals forces

    • What is the primary function of noncovalent forces in biological systems?

  • To break down molecules
  • To create permanent bonds between molecules
  • To contribute to the structure, stability, and functional competence of macromolecules (correct)
  • To repel molecules from each other

    • What type of interaction is responsible for the attraction between positively charged nuclei and electrons of nearby atoms?

  • Electrostatic interactions
  • Dispersion forces
  • Induced electrical interactions (correct)
  • Dipole-dipole interactions

    • What is the range of decrease in interaction energy for dipole-dipole interactions?

    <p>1/r3</p> Signup and view all the answers

    What type of force is responsible for the attraction between all molecules, including those without permanent dipoles?

    <p>Dispersion forces</p> Signup and view all the answers

    What is the distance over which van der Waals attractions operate?

    <p>Limited interatomic distance</p> Signup and view all the answers

    What is necessary for van der Waals attractions to be effective at physiological temperatures?

    <p>A number of atoms in a molecule interacting with several atoms in a neighboring molecule</p> Signup and view all the answers

    Why must atoms on interacting molecules pack together neatly for van der Waals attractions to be effective?

    <p>To allow a number of atoms in a molecule to interact with several atoms in a neighboring molecule</p> Signup and view all the answers

    What is the equilibrium constant given by?

    <p>The ratio of the forward reaction rate to the reverse reaction rate</p> Signup and view all the answers

    What is the effect of enzymes on the equilibrium position of a reaction?

    <p>Enzymes do not alter the equilibrium position of a reaction</p> Signup and view all the answers

    What is the purpose of oxidative phosphorylation?

    <p>To generate energy for the cell</p> Signup and view all the answers

    What is the pH of the blood in healthy individuals?

    <p>7.4</p> Signup and view all the answers

    What is the end product of the oxidation of macromolecules?

    <p>Carbon dioxide and water</p> Signup and view all the answers

    What are the three stages of catabolism?

    <p>Not specified in the text</p> Signup and view all the answers

    What is the purpose of buffering in biological fluids?

    <p>To resist changes in the pH of the fluid</p> Signup and view all the answers

    What is the pK of the phosphate ion?

    <p>6.82</p> Signup and view all the answers

    What is the role of electron carriers in oxidative phosphorylation?

    <p>To transfer electrons from metabolic intermediates</p> Signup and view all the answers

    What is the result of oxidation reactions?

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

    Why is it crucial to buffer the pH of a solution when working with enzymes and proteins?

    <p>To avoid denaturation of the protein</p> Signup and view all the answers

    What is the ultimate source of energy for the cell?

    <p>Glucose, proteins, and lipids</p> Signup and view all the answers

    What is the pH range in which many biological molecules are effective at buffering?

    <p>pH 6-8</p> Signup and view all the answers

    What is the name of the ion that helps maintain the pH of extracellular fluid between 7.35 and 7.45?

    <p>Bicarbonate ion</p> Signup and view all the answers

    What is the term used to describe a disturbance in the body's acid-base balance?

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

    What is the purpose of measuring the pH of arterial blood and the CO2 content of venous blood?

    <p>To diagnose acid-base disorders</p> Signup and view all the answers

    What is the pH of a solution considered to be neutral?

    <p>7.0</p> Signup and view all the answers

    What does a pH below 7.0 indicate about a solution?

    <p>It has more hydrogen ions</p> Signup and view all the answers

    What is the purpose of buffers in the body?

    <p>To maintain pH levels</p> Signup and view all the answers

    What is the pH of the body?

    <p>7.4</p> Signup and view all the answers

    What is the result of a solution having a pH of 5.0?

    <p>It contains more hydrogen ions than water</p> Signup and view all the answers

    What is the role of the bicarbonate - carbonic acid system in the body?

    <p>To maintain pH levels</p> Signup and view all the answers

    Why is it important to maintain pH levels in the body?

    <p>For body enzymes to be active and for chemical reactions to proceed optimally</p> Signup and view all the answers

    What is the pH scale measured from?

    <p>0 to 14</p> Signup and view all the answers

    What is the result of combining HCO3- with hydrogen ions?

    <p>Formation of H2CO3</p> Signup and view all the answers

    What is the pH range for acidosis?

    <p>pH below 7.35</p> Signup and view all the answers

    What is the purpose of measuring pH in biochemistry?

    <p>To diagnose diseases</p> Signup and view all the answers

    What is the normal pH value of blood plasma?

    <p>pH 7.4</p> Signup and view all the answers

    What is the term for an excess of base in the blood that causes the pH to rise above 7.45?

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

    What is the formula for calculating the anion gap?

    <p>Gap = Na+ + K+ - Cl- - HCO3-</p> Signup and view all the answers

    What is the result of combining OH with H2CO3?

    <p>Formation of HCO3- and H2O</p> Signup and view all the answers

    What is the term for an excess of acid in the blood that causes the pH to fall below 7.35?

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

    Study Notes

    Covalent and Noncovalent Forces

    • Covalent bonds are the strongest forces that hold molecules together
    • Noncovalent forces, although weaker, contribute significantly to the structure, stability, and functional competence of macromolecules in living organisms
    • Examples of noncovalent forces include hydrophobic interactions, electrostatic interactions, and van der Waals forces

    Van der Waals Forces

    • Result from induced electrical interactions between closely approaching atoms or molecules due to fluctuations in electron clouds
    • Include dipole-dipole interactions, dipole-induced dipole interactions, and induced dipole-induced dipole interactions (London dispersion forces)
    • Contribute to attractive intermolecular forces between all molecules, including those without permanent dipoles

    Energy and Oxidative Phosphorylation

    • Energy is made available to cells by breaking down high-energy chemical bonds in food substances (carbohydrates, proteins, and lipids) through enzymatic conversion to their monomer units
    • Oxidation of these molecules occurs in small controlled steps to carbon dioxide and water, releasing energy
    • Stages of catabolism: extraction of energy from fuels can be divided into three stages

    Buffers and pH Regulation

    • Buffers resist changes in pH of a solution by acting as acid-base conjugate pairs (e.g., acetic acid and acetate)
    • Effective buffering occurs within 1 pH unit of the pK (pK+1)
    • Biological fluids, including blood, are buffered to maintain a narrow pH range (pH 6-8)
    • Major buffering components in biological fluids include phosphate and carbonate ions, as well as acid-base groups in amino acids, proteins, nucleic acids, and lipids

    Acid-Base Disorders and pH Measurement

    • pH is a measure of hydrogen ion concentration in body fluids, with a pH range of 0-14 and a neutral pH of 7.0 (water)
    • Acidosis occurs when pH falls below 7.35, and alkalosis occurs when pH rises above 7.45
    • pH measurement is crucial in biochemistry and medical diagnoses, as it affects the structure and activity of biological macromolecules

    Studying That Suits You

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

    Quiz Team

    Description

    This quiz covers covalent bonds, the strongest force holding molecules together, and noncovalent forces such as hydrophobic interactions, electrostatic interactions, and van der Waals forces, which contribute to the structure and stability of macromolecules in living organisms.

    More Like This

    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser