A&P (1).txt

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A&P (1).txt
2015-06-03 04:13:39
ap chap2
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  1. matter
    • anything that occupies space and has mass
    • can be seen, smelled, and felt
  2. energy
    the capacity to do work, or to put matter into motion
  3. kinetic energy
    energy in action
  4. potential energy
    • stored energy
    • potential energy has the capability to do work but is not presently doing so
  5. chemical energy
    form stored in the bonds of chemical substances

    *found in food we eat
  6. electrical energy
    results from movement of charged particles.

    • *transmits messages in body.
    • *found in flow of electrons along household wiring
  7. mechanical energy
    energy directly involved in moving matter

    *when riding a bike, your legs directly provide mechanical energy to move pedals
  8. radiant energy, or electromagnetic energy
    energy that travels in waves

    *include visible light, infrared waves, radio waves, UV waves, and xrays
  9. elements
    unique substances that cannot be broken down into simpler substances by ordinary chemical methods

    -- all matter is composed of elements
  10. atoms
    building blocks of everything

    -smallest particle of an elemental substance that exhibits the properties of that element; composed of protons, neutrons, and electrons

    -- comes from the Greek word "indivisible"
  11. nucleus
    • control center of a cell
    • contains genetic material
    • clusters of nerve cell bodies in CNS
  12. neutron
    • uncharged subatomic particle
    • found in atomic nucleus
    • neutral, so nucleus is positively charged overall
  13. protons
    • subatomic particle that bears positive electrical charge
    • located in atomic nucleus
  14. electrons
    • negatively charged subatomic particle
    • orbits the atom's nucleus
  15. oxygen (O)
    • a major component of both organic (carbon-containing) and inorganic (non-carbon-containing) molecules.  As a gas, it is needed for the production of cellular energy (ATP)
    • 65% body mass
  16. carbon (C)
    • primary component of all organic molecules, which include carbohydrates, lipids (fats), proteins, and nucleic acids
    • 18.5% body mass
  17. hydrogen (H)
    • component of all organic molecules. As an ion (proton), it influences pH of all body fluids
    • 9.5% body mass

    is the simplest atom with just 1 proton and 1 electron and no neutrons
  18. nitrogen (N)
    • component of proteins and nucleic acids (genetic material)
    • 3.2% body mass
  19. calcium (Ca)
    • found as a salt in bones and teeth.  Its ionic (Ca2+) form is required for muscle contraction, conduction of nerve impulses, and blood clotting
    • 1.5% body mass
  20. phosphorus (P)
    • part of calcium phosphate salts in bones and teeth.  also present in nucleic acids, and part of ATP
    • 1% body mass
  21. potassium (K)
    • its ion (K+) is the major positive ion (cation) in cells.  necessary for conduction of nerve impulses and muscle contractions
    • .4% body mass
  22. sulfur (S)
    • component of proteins, particularly muscle proteins
    • 0.3% body mass
  23. sodium (Na)
    • as an ion (Na+), sodium is the major positive ion found in extracellular fluids.  Important for water balance, conduction of nerve impulses, and muscle contraction
    • 0.2% body mass
  24. Chlorine (Cl)
    • its ion (chloride, Cl-) is the most abundant negative ion (anion) in extracellular fluids
    • 0.2% body mass
  25. magnesium (Mg)
    • present in bone
    • important cofactor in a number of metabolic reactions.
    • 0.1% body mass
  26. Iodine (I)
    • needed to make functional thyroid hormones
    • 0.1% body mass
  27. iron (Fe)
    • component of hemoglobin (which transports oxygen w/in RBCs) and some enzymes
    • 0.1% body mass
  28. atomic number
    • equal to the number of protons in its nucleus and is written as a subscript to the left of its atomic symbol.
    • the #protons is always equal to the #electrons in an atom, so the atomic # will indirectly tell you the # of electrons in atom as well
  29. mass number
    sum of the masses of its protons and neutrons of an atom
  30. isotopes
    different atomic forms of same element, which vary only in # of neutrons they contain
  31. atomic weight
    • average of the relative weights (mass numbers) of all the isotopes of an element
    • atomic weight of element is approx equal to the mass # of its most abundant isotope
  32. radioisotopes
    isotopes that exhibit behavior of radioactivity (atomic decay)
  33. molecule
    combination of two or more atoms held together by chemical bonds
  34. compound
    two or more different kids of atoms bind, forming molecules

    *2 hydrogen atoms combine w/1 oxygen atom to form the compound H20

    -- compounds are chemically pure and all their molecules are identical
  35. mixtures
    • physical combinations of solutes in a solvent
    • mixture components retain their individual properties

    *3 basic types: solutions, colloids, suspensions
  36. mole
    a mole of any element or compound is equal to its atomic weight or its molecular weight (sum of atomic weights) measured in grams
  37. molarity
    a way to express the concentration of a solution; moles per liter of solution
  38. solutions
    homogeneous mixtures of components that may be gases, liquids, or solids
  39. homogeneous
    mixture has exactly the same composition or makeup throughout
  40. solvent
    substance present in the greatest amount

    *water is the body's chief solvent
  41. solutes
    substances present in smaller amounts
  42. heterogeneous
    composition is dissimilar in different areas of the mixture
  43. colloids
    • aka emulsions
    • often appear translucent or milky - do not settle out
    • scatter light
    • can undergo sol-gel transformations (change reversibly from fluid (sol) to a solid (gel)
  44. suspension
    heterogeneous mixture w/large, often visible solutes that tend to settle out.

    *sand and water mixture
  45. valence shell
    atom's outermost energy level or that portion of it containing the electrons that are chemically reactive
  46. octet rule or rule of eights
    • the key to chemical reactivity
    • atoms tend to interact in such a way that they have 8 electrons in their valence shell (except for shell 1 which is full when it has 2 electrons)
  47. ionic bond
    chemical bond b/w atoms formed by the transfer of one or more electrons from one atom to the other
  48. anion

    anion - negative charge

    cation - positive charge

    *both formed whenever electron transfer b/w atoms occurs
  49. covalent bond
    formed when atoms share electron pairs. If electron pairs shared equally, the molecule is nonpolar.  If shared unequally, it is polar (a dipole)
  50. hydrogen bonds
    • weak bonds formed b/w one hydrogen atom and another electronegative atom (such as nitrogen or oxygen)
    • Bind together different molecules or different parts of same molecule
  51. exergonic reactions
    reactions that release energy - yield products w/less energy
  52. catalysts
    substances that increase the rate of chemical reactions w/o themselves becoming chemically changed or part of the product

    *biological catalysts are called enzymes