Skip to main content
Indietro

General Biology: Water, Organic Molecules, and Basic Biochemistry

I pulsanti di controllo sono stati cambiati in modalità "navigazione".
1/29

Termini in questo insieme (29)

  • How is genetic information preserved during DNA copying?
    Genetic information is preserved by base pairing between A and T and between G and C across the two strands of the double helix.
  • What type of traits does natural selection act on?
    Natural selection acts only on heritable traits.
  • What are the three fundamental domains of life identified by Carl Woese?
    The most fundamental division among organisms is between Archaea, Bacteria, and Eukarya.
  • Which bond must be broken for water to vaporize?
    Hydrogen bonds must be broken for water to vaporize.
  • Why do ionic molecules dissolve in water?
    Water is a polar solvent, so polar and ionic substances readily dissolve and dissociate in it.
  • How is household bleach characterized chemically?
    Household bleach is a base with a pH greater than 7.
  • What is the defining characteristic of hydrolysis?
    Hydrolysis breaks down polymers into monomers by using a water molecule.
  • What gives organic molecules their overall shape and chemical behavior?
    Carbon atoms give organic molecules their shape, while H, N, and O atoms determine their chemical behavior.
  • Why is carbon important for the complexity of organic molecules?
    The complexity and variety of organic molecules is due to the chemical versatility of carbon atoms.
  • What reactions involve the formation and breaking of water molecules?
    Condensation reactions form water molecules; hydrolysis reactions break water molecules.
  • Why might silicon-based life be possible on other planets?
    Silicon has the same number of valence electrons as carbon, allowing it to form the same number of covalent bonds.
  • Which functional group contains nitrogen?
    The amino group contains nitrogen.
  • What determines molecular properties and chemical reactions in molecules?
    The functional group determines molecular properties and reaction types.
  • What is the strongest to weakest order of chemical bonds?
    Strongest to weakest: ionic > covalent > hydrogen > Van der Waals.
  • What does a low pH indicate about proton concentration?
    Low pH means a high concentration of protons (H+).
  • How many hydrogen bonds can a water molecule form?
    A water molecule can form up to 4 hydrogen bonds.
  • What roles does water play in the body?
    Water transports nutrients and waste, maintains acid-base balance, and aids in thermoregulation.
  • What is a nonpolar covalent bond?
    Two atoms share electrons equally or almost equally, e.g., C–H or O=O bonds.
  • What is a polar covalent bond?
    Two atoms share electrons unequally, creating partial charges (δ− and δ+), e.g., O–H in water.
  • What is a hydrogen bond?
    A noncovalent attraction between a δ+ hydrogen bonded to O, N, or F and a nearby δ− O, N, or F.
  • Why is water considered a polar molecule?
    Oxygen attracts electrons more strongly than hydrogen, giving water a partial negative charge on O and partial positive charges on H.
  • What causes water's cohesion and adhesion?
    Hydrogen bonding causes water molecules to stick to each other (cohesion) and to other substances (adhesion).
  • What is water's high specific heat important for?
    Water's high specific heat helps organisms maintain stable internal temperatures.
  • Why does ice float on water?
    Hydrogen bonds stabilize in ice, making it less dense than liquid water.
  • What is a solvent, solute, and solution?
    Solvent dissolves substances, solute is dissolved, and solution is the homogeneous mixture of both.
  • What are hydrophilic, hydrophobic, and amphipathic molecules?
    Hydrophilic dissolve in water, hydrophobic do not, amphipathic have both hydrophilic and hydrophobic regions.
  • What ions result from water ionization?
    Water ionizes into hydronium (H3O+) and hydroxide (OH-) ions.
  • What does the pH scale measure?
    The pH scale measures the concentration of hydrogen ions (H+) to indicate acidity or basicity.
  • How do acids, bases, and buffers affect pH?
    Acids donate H+, bases donate OH- or accept H+, and buffers minimize pH changes by absorbing or releasing H+.