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Anatomy & Physiology - Chemistry of Life

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이 집합의 용어 (23)

  • What are the three main subatomic particles of an atom?
    Protons (positive charge), Neutrons (neutral), and Electrons (negative charge). Protons and neutrons are in the nucleus; electrons orbit in shells.
  • What defines an element?
    An element is a substance composed of atoms with the same number of protons (atomic number) and cannot be broken down chemically.
  • What are the four major elements that make up 96% of the human body mass?
    Oxygen (65%), Carbon (18%), Hydrogen (10%), and Nitrogen (3%).
  • What is an isotope?
    Atoms of the same element with the same number of protons but different numbers of neutrons, resulting in different mass numbers.
  • What is an ionic bond?
    A chemical bond formed by the transfer of electrons from a metal to a nonmetal, creating oppositely charged ions (cations and anions) that attract.
  • How do covalent bonds differ from ionic bonds?
    Covalent bonds involve sharing electrons between nonmetal atoms, while ionic bonds involve electron transfer between metal and nonmetal atoms.
  • What is the difference between nonpolar and polar covalent bonds?
    Nonpolar covalent bonds share electrons equally; polar covalent bonds share electrons unequally, creating partial charges (dipoles).
  • What are hydrogen bonds?
    Weak attractions between partially positive hydrogen atoms and partially negative atoms in polar molecules, important for water's properties.
  • Why is water considered a polar molecule?
    Because oxygen has higher electronegativity, it pulls electrons more strongly, creating partial negative and positive poles in the molecule.
  • What is the role of enzymes in chemical reactions?
    Enzymes act as biological catalysts that lower activation energy and speed up reactions without being consumed.
  • What is the 'induced fit' mechanism of enzyme action?
    The enzyme changes shape slightly to fit the substrate more snugly when the substrate binds to the active site.
  • What is the pH scale and what does it measure?
    The pH scale measures hydrogen ion concentration; values below 7 are acidic, 7 is neutral, and above 7 are basic (alkaline).
  • What are acids and bases in terms of hydrogen ions?
    Acids donate hydrogen ions (H+), increasing their concentration; bases accept hydrogen ions, decreasing their concentration.
  • What is a buffer and why is it important in the body?
    A buffer resists changes in pH by neutralizing added acids or bases, maintaining homeostasis, e.g., the carbonic acid-bicarbonate system in blood.
  • What are the four main classes of organic compounds in the body?
    Carbohydrates, Lipids, Proteins, and Nucleic Acids.
  • What is the primary function of carbohydrates?
    To provide fuel (energy) and some structural roles; they are polar and hydrophilic molecules.
  • What are triglycerides and their function?
    Triglycerides are fats made of three fatty acids and glycerol; they store energy and can be solid or liquid.
  • What is the structure and function of phospholipids?
    Phospholipids have a hydrophilic phosphate head and two hydrophobic fatty acid tails; they form the main structure of cell membranes.
  • What are steroids and their biological importance?
    Steroids have a 4-ring hydrocarbon structure; cholesterol is a base steroid and precursors for hormones like estrogen and testosterone.
  • What are proteins made of and their general functions?
    Proteins are made of amino acids and function in structure, enzymes, defense, communication, muscle contraction, and more.
  • What causes protein denaturation?
    Heat, pH changes, and chemicals disrupt hydrogen and ionic bonds, causing proteins to lose their shape and function.
  • What are nucleotides and their role in nucleic acids?
    Nucleotides are monomers composed of a nitrogenous base, sugar, and phosphate group; they form DNA and RNA.
  • What is ATP and why is it important?
    Adenosine triphosphate (ATP) is the main energy currency of the cell, providing energy for cellular processes through hydrolysis.