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2011-12-13 16:36:45
Bio 196

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  1. 1.3
    What is the scientific method?
    • 1. make observation
    • 2. ask questions
    • 3. form hypothesis
    • 4. make predictions based on hypothesis
    • 5. test the predictions

    Inductive knowledge is used.
  2. 1.3
    what is a controlled experiment?
    the sample is the same with a manipulatable variable
  3. 1.3
    what is a comparative experiment?
    there is no variable that is controlled. there is simply observation between the groups being tested.
  4. 1.3
    what is a null hypothesis?
    no difference exists.
  5. 2.1
    Matter is composed of atoms. What is the structure of an atom?
    Atoms have a positively charged nucleus that contains protons and neutrons. The nucleus is surrounded by negative electrons.
  6. 2.1
    What does the number of protons in the nucleus determine?
    The atomic number.
  7. 2.1
    What is the difference between isotopes and radioisotopes?
    • Isotopes have a different number in neutrons than their element regularly does.
    • Radioisotopes are radioactive and emit radiation as they break down.
  8. 2.1
    What creates a molecule?
    the losing or gaining of electrons of an atom to combine with other atoms.
  9. 2.2
    Why is a covalent bond stronger than an ionic bond?
    • Covalent bonds are stronger because two atoms will join together and share electrons from their outer shells.
    • Ionic bonds just either gain or lose electrons just so that each atom can be stable.
  10. 2.2
    How do variations in electronegativity result in the unequal sharing of electrons in polar molecules?
    If one nucleus of an atom has a greater attractive force than the other atom, the shared electron pair will be closer to the atom with the greater electronegativity. This causes variations in the polarity in the molecule. The molecule can end up being partially negative, or partially positive. If the two atoms have the same electronegativity, then they are a nonpolar colvalent bond.
  11. 2.2
    What is a hydrogen bond and how is it important in biological systems?
    • Hydrogen bonds are weaker than covalent bonds and most ionic bonds because they are formed by partial negative and partial positive charges. Positive and Negative attract=hydrogen bond.
    • Hydrogen bonds are important because alone, they're weak, but many of them can form between just one molecule. They can form and grow quickly in strength.
  12. 2.2
    Polar molecules interact with other polar molecules. They are water loving and hydrophilic.
  13. 2.2
    • Nonpolar molecules interact with other nonpolar molecules. They do not like water and they are hydrophobic.
    • These interactions are enhanced by van der waals forces when two nonpolar molecules are very close to eachother.
  14. 2.4
    What are important biological properties of water arising from its chemical structure?
    Water is a polar molecule that forms hydrogen bonds. Its electron pairs repel from one another and allow ice to float, to melt and freeze, to store heat, dissolve, and form into droplets.
  15. 2.4
    what is a solution? why is water called the medium of life?
    A solution is when a substance is completely dissolved into the liquid. It is called the medium of life because all living things need it.
  16. 2.4
    What is the relationship between hydrogen ions, acids, and bases?
    what is an example of each?
    • Aqueous solutions give off hydrogen ions (H+) and can be acidic or basic.
    • If the substance releases H+ then it is an acid.
    • HCl --> H+ + Cl-

    • If the substance takes in H+ then it is a base.
    • NaOH --> Na+ + OH-
  17. 2.4
    What is PH?
    • The hydrogen ion concentration.
    • A low ph means its a strong acid, a high ph means its a weak acid.
    • A ph value of 7, or 10-7 means it is a neutral ph (distilled water)
  18. 2.4
    what is a buffer?
    A buffer is a mixture of a weak acid and a base that limits changes in the ph of a solution. Its important it is the maintenance of internal consistency-homeostasis