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2011-09-20 01:49:39

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  1. What is anecdotal evidence?
    an informal observation that has not been systmatically tested
  2. What is the significance of peer review in science?
    you can trust it; independent and unbgiased experts have critiqued the soundness of the study before it was published
  3. What is a hypothesis?
    a testable and falsifiable explanation for a scientific observation or question
  4. What are the characteristics of a good hypothesis?
    specific and testable
  5. What is the difference between the independent and dependent variable?
    • independent: the variable that is changed in a systematic way
    • dependent: the variable that is measured in the experiment
  6. What is the control group?
    the group in an experiment that experiences no experimental intervention or manipulation
  7. What is the experimental group?
    the group in an experiment that experiences the experimental intervention or manipulation
  8. How does sample size influence the validity of results in a scientific experiment?
    • can stregthen our confidence in the results of the study
    • the number of experimental subjects or the number of times an experiment is repeated
  9. What is a placebo?
    a fake treatment given to control groups to mimic the experience of the experimental groups
  10. Why do scientists use placebos?
    • to avoid a placebo effect
    • mind over matter
  11. What does correlation between two varriables indicate?
    consistent relationship between the variables; doesn't prove one causes the other
  12. What is epidemiological study?
    the study of patterns of disease in populations including risk factors
  13. Why are epidemiological studies used in science?
    • to answer questions that could not be tested through experiments for ethical or practical reasons
    • ex: Does smoking cause cancer?
  14. What is the scientific theory?
    A hypothesis that is supported by many years of rigorous testing and thousands of experiments
  15. What are the 5 functional traits that all living things share in common?
    • growth
    • reproduction
    • homeostasis
    • sense and respond to stimuli
    • obtain and use energy
  16. What is energy?
    the ability to do work
  17. How do all organisms obtain energy?
    sunlight or food
  18. What is an atom?
    the smallest unit of an element that cannot be chemically broken down into smaller units
  19. What is a proton?
    a positively charged particle located in the nucleus of an atom
  20. What is a neutron?
    a neutral charged subatomic particle located in the nucleus of an atom
  21. What is an electron?
    a negatively charged subatomic particle with negligible mass
  22. What is a nucleus (atom)?
    the dense core of an atom
  23. How many electrons are found on each shell or orbital?
    • 2 on the first
    • 8 on the rest
  24. What is atomic mass?
    the number of protons and neutrons
  25. How many partners can carbon form bonds with?
  26. What is a covalent bond?
    a strong chemical bond resulting from the sharing of a pair of electrons between 2 atoms
  27. What is a hydrogen bond?
    a weak electrical attraction between a partially positive hydrogen atom and another atom with a partial negative charge
  28. What is an ionic bond?
    a strong electrical attraction between oppositely charged ions
  29. what is homeostasis?
    the maintenance of a relatively constant internal environment
  30. What makes an atom charged?
    when there are more protons than electrons; or more electrons than protons
  31. How can atom become charged?
    by loosing or gaining electrons in an attempt to achieve octet
  32. What forms cell membranes?
    a phospholipid bilayer
  33. What characteristic of phospholipid bilayers makes them suited for their task?
    its semipermeable
  34. What is an ion?
    an electrically charged atom, the charge resulting from the looss or gain of electrons
  35. How does an ion form?
  36. What does pH measure?
    concentration of H+ in a solution
  37. How does the pH scale work?
    • 0= acidic pH
    • 7= neutral pH
    • 14= basic pH
  38. What is an acid?
    a substance that increases the hydrogen ion concentration of solutions, making them more acidic
  39. What is a base?
    a substance that reduces hydrogen ion concentration of solutions, making them more basic
  40. What makes up protein?
    amino acids
  41. What makes up carbohydrates?
    polymers made of monomers; monosaccharides
  42. What is the unifying feature of lipids?
    hydrophobic molecules (dont mix with water)
  43. What are examples of complex sugars?
  44. What are examples of simple sugars?
  45. What is a polar molecule?
    a molecule in which electrons are not shared equally between atoms causing a partial neg. charge at one end and a partial pos. charge at the other; for example water.
  46. What did Alexander Fleming discover?
  47. How did Fleming make his discovery?
    he was throwing away a petri plate when he noticed that wherever mold was growing there was a zone of inhabbition where bacteria did not grow
  48. What is an antibiotic?
    a chemical that can slow or stop the growth of bacteria; many are produced by living organisms
  49. What is penicillin?
    antibacterial substance
  50. Where does penicillin come from?
    Penicillium notatu; mold
  51. What is the cell theory?
    the concept that all living organisms are made of cells and that cells are formed by the reproduction of existing cells.
  52. What is the difference between a prokaryotic and eukaryotic cells?
    prokaryotic cells don't have organelles
  53. What structures are found in prokaryotic cells?
    cell membrane, cytoplasm, ribosomes, DNA
  54. What structures are found in eukaryotic cells?
    Nucleus, cell membrane, cytoplasm, ribosomes, DNA, mitochondria, lysosomes, chloroplasts, Golgi, ER, cytoskeleton... ect.
  55. Why do antibiotics kill bacterial cells and not human cells? Specificallly in the case of penicillin?
  56. What are bacterial cell walls made of?
    peptidoglycan, a polymer made of sugars and amino acids
  57. Describe the cell membrane and the orientation of phospholipids in the membrane.
    Phospholipids assemble into bilayers in water. Water-hatingtails congregate betweenwater-loving heads, forming a lipid sandwich
  58. What is diffusion?
    the movement of particles from an area of high concentration to an area of lower concentration
  59. What is osmosis?
    the diffusion of water across a semipermeable membrane from an area of lower solute concentration to an area of higher solute concentration
  60. What happens to a cell in a hypertonic solution?
    cells shrink
  61. What happens to a cell in a hypotonic solution?
    cells expand
  62. What happens to a cell in an isotonic solution?
    cells remain the same
  63. Why are transport proteins needed by the cell?
    provide a passageway for large or hydrophillic molecules to move across the membrane
  64. What is facilitated diffusion? Does it require energy?
    the process by which large or hydrophobic solutes move across a membrane from an area of higher concentration to an area of lower concentration with the help of transport proteins. DOES NOT REQUIRE ENERGY
  65. What is active transport? Does it require energy?
    process by which solutes are pumped from an area of lower concentration to an area of higher concentration with the help of transport proteins. REQUIRES ENERGY
  66. What are ribosomes and what do they do?
    a complex of RNA and protein that carries out protein synthesis in all cells
  67. What is the function of chloroplasts?
    site of photosynthesis
  68. What is the function of lysosomes?
    filled with enzymes that can degrade worn-out cellular structures
  69. What is the function of mitochondria?
    membrane-bound organelles responsible for important energy conservation ractions in eukaryotes
  70. What is the function of the nucleus?
    stores genetic material
  71. What is the function of the cytoskeleton?
    a network of protein fibers in eukaryotic cells that provides strucuture and facilitates cell movement.
  72. What is the endosymbiotic theory?
    the theory that freeliving prokaryotic cells engulfed other freeliving prokaryotic cells billions of years ago forming eukaryotic organelles such asw mitochondria and chloroplasts
  73. What are the four macronutrients?
    proteins, carbohydratesw, fats, nucleic acids
  74. How do human bodies utilize macronutrients?
    nutrients, including proteins, carbohydrates, and fats, that organisms must ingest in large amounts to maintain health
  75. What is an essiential amino acid?
    eight amino acids in the human body cannot synthesize and must be obtained from food
  76. What is a non-essential amino acid?
    amino acids that our body can produce itself
  77. What are enzymes?
    a protein that speeds up the rate of chemical reactions
  78. What do enzymes do?
    accelerate chemical reactions
  79. How do enzymes work?
    reduce the activation energy
  80. What is activation energy?
    the energy required for a chemical reaction to proceed.
  81. What is substrate?
    a compound or molecule that an enzyme binds to and on which it acts
  82. What is a catabolic reaction?
    any chemical reaction that breaks down complex molecules into simpler molecules
  83. What is an anabolic reaction?
    any chemical reaction that combines simple molecules to build more complex molecules
  84. What is the difference between type 1 and type 2 diabetes?
    • type 1: cannot make insulin
    • type 2: the receptors on their cells respond poorly to insulin