Chemistry of water (2.3) and Acid and Bases (2.4)

Cards (43)

  • A chemical reaction is the process of...
    making or breaking a bond
  • What is an example of a chemical reaction with bread?
    Eating bread as the saliva is breaking chemical bonds
  • What is the definition of metabolism in biology?
    All the chemical reactions in a cell or organism
  • How do covalent bonds form?
    When two atoms share electrons
  • What are the two types of covalent bonds?
    Polar and nonpolar
  • What is a nonpolar covalent?
    equal sharing of electrons (ex: methane)
  • What is a polar covalent?
    Unequal sharing of electrons (ex: H2O)
  • Do most biomolecules contain polar or nonpolar covalent bonds?
    Polar
  • What element do polar bonds often have?
    oxygen
  • What is electronegativity?
    the ability of an atom to attract electrons towards itself
  • What element is the most electronegative?
    oxygen
  • What is Nitrogen's level of electronegativity?
    slightly electronegativity
  • What does it mean that Carbon and Hydrogen are electropositive?
    easier to give away electrons
  • What can polar molecules make?
    hydrogen bonds with other polar molecules
  • What are hydrogen bonds?
    weak attraction between a slightly positive hydrogen atom and a slightly negative atom
  • Polar covalent bonds lead to ___ and then lead to ___ and then lead to ___
    hydrogen bonds, surface tension/capillary reaction/evaporating cooling (sweating)
  • Is a single hydrogen bond weak or strong?
    Weak
  • Are multiple hydrogen bonds weak or strong
    strong
  • What chemical characteristics does water have due to hydrogen bonds?
    cohesive/adhesive, molecules dissolving, absorb much energy, ice is less dense than liquid water
  • Why is water "sticky"
    hydrogen bonds
  • What are enzymes?
    proteins
  • What are exoskeletons made out of?
    chitin
  • Where are neutrons and protons located?
    Nucleus
  • What is the definition of cohesion?
    water molecules hydrogen bonding to other water molecules
  • What does cohesion lead to?
    surface tension
  • What is the definition of adhesion?
    Water molecules hydrogen bonding to other polar surfaces
  • How does water move through plants?
    capillary action
  • What is capillary action?
    the combination of adhesion and cohesion
  • What is evaporative cooling (sweating)
    As water evaporates, it pulls heat from the organism
  • What bonds must be broken to evaporate?
    Hydrogen
  • What is the pH scale?
    measures acidity or alkalinity of a liquid
  • Why is pH important in biology?
    impacts biochemical reactions
  • Organisms change ___ of different parts of their --- to manipulate ---.
    pH
    body
    chemistry
  • pH scale: 0-7
    acidic (positive protons, hydrogen ion, H+)
  • pH scale: 7
    neutral
  • pH scale: 7-14
    Basic (Alkaline) (negative hydroxyl ions, -OH)
  • pH varies in ___ and ___
    body
    temperature
  • What keeps pH constant?
    Buffers
  • What is the definition of buffer?
    chemicals that keeps pH within normal limits (homeostasis)
  • What are three built-in mechanisms does the human body to prevent pH changes?
    kidney, lungs, buffers