BIOLOGY 1030

SUMMER 1999


UNIT IV. STAYING ALIVE



Some key terms and ideas
  1. Another review of basic chemistry
    1. atoms and elements
      1. the periodic chart
      2. the basic elements of life: carbon, hydrogen, oxygen, nitrogen, sulfur, and phosporus
      3. additional elements required by living things
    2. water and its properties
      1. polar molecule
      2. interacts with itself
        1. cohesive with relatively high surface tension
        2. relatively high heat capacity
        3. maximum density of liquid water at 4 C
      3. interacts with ions and polar compounds
        1. adhesive
        2. acts as solvent to form solutions -- these can bring reactants together
          1. percent concentration (grams/deciliter; milligrams/deciliter)
          2. molarity
        3. acids defined by ability to increase the concentration of hydrogen ions in water -- pH is a molarity scale -- bases remove hydrogen ions (usually producing hydroxide ions), buffers stabilize pH
      4. interacts with non-polar compounds through exclusion (hydrophobic interactions)
    3. salts and ions (electrolytes)
      1. major minerals: sodium, potassium, calcium, chloride ions, phosphorus (phosphate ions), magnesium, sulfur
      2. trace elements: iron, iodine, cobalt, zinc, etc.
    4. primary organic compounds
      1. hydrocarbons
      2. functional groups
        1. major groups: hydoxyl, carboxyl, amino, sulfhydryl, phosphate
        2. example: ethane, ethanol, acetic acid, aminoethane
      3. fats and lipids
        1. saturated and unsaturated fatty acids
        2. mono-, di-, and triglycerides
        3. cholesterol, HDLs, and LDLs
      4. sugars and polysaccharides
      5. amino acids and proteins
  2. Nutritional constraints
    1. under nourished  vs malnourished
    2. law of mass conservation and nutritional balances
      1. oxygen and ATP formation
      2. nitrogen compounds
        1. nitrogen balance and protein in the diet
        2. essential amino acids and fatty acids
      3. calcium regulation -- calcitonin (decrease) and parathyroid hormone (increase)
      4. iron metabolism and the role of the liver
    3. laws of thermodynamics
      1. major energy molecules:  ATP and NADH
      2. sources of ATP
        1. substrate-level ATP formation
        2. electron-transport ATP formation and aerobic respiration (in the mitochondria of eukaryotes)
          1. builds up a hydrogen ion concentration across the inner membrane of the mitochondrion as electrons move from molecule to molecule of an electron transport chain through a series of exergonic reactions
          2. the energy associated with the hydrogen ions is used to glue a phosphate ion on to an ADP, forming ATP
      3. energy molecules
        1. ATP from glucose
          1. glycolysis, the initial splitting of glucose releases a net of 2 ATP and 2 NADH; key intermediates and end-products include energized fructose, PGAL, and pyruvate
            1. if unable to use the NADH to make ATP then continue with some sort of fermentation
          2. pyruvate moves to mitochondria, forming more NADH; carbon dioxide and acetyl-coenzyme A produced
          3. Krebs cycle removes the rest of the energy from the remains of the pyruvate (the acetyl), producing 3 NADH, 1 FADH2, and 1 ATP for each acetyl; key intermediates include citrate, alpha-keto-glutarate, succinate, malate, and oxaloacetate
          4. each NADH can be used to make 3 ATP and each FADH2 can be used to make 2 ATP, for a total of about 36-38 ATP for each glucose molecule
        2. energy from starches
        3. energy from triglycerides
          1. first separate into fatty acids and glycerol
          2. the glycerol is converted to PGAL
          3. the fatty acids are converted to acetyl-coenzyme A
        4. energy from protein
          1. first separate into amino acids and remove the amino group (deamination)
            1. converted to urea
          2. remove any other nitrogen or sulfur groups
          3. feed the remaining carbon skeleton into glycolysis or Krebs as appropriate
      4. energy requirements -- basal metabolic rate; for humans roughly 12 times body weight; physical activity increases the requirement
  3. Acquiring and transferring nutrients
    1. digestive systems
      1. basic digestive systems
      2. the human system: mouth-pharynx, esophagus, stomach, small intestine, large intestine
      3. modifications: cows and dinosaurs
    2. respiratory systems
      1. gills vs lungs; transfer of chemicals
      2. blood and hemoglobin; properties of hemoglobin
    3. circulatory systems
      1. arteries, veins, and capillaries
      2. mechanisms of flow
        1. cardiac cycle and four-chambered heart
        2. blood pressure
          1. sroke volume and pulse rate (acetylcholine and epinephrine)
          2. vasoconstriction and vasodilation (histamine, angiotensins)
          3. blood volume (ADH) and blood viscosity (erythropoietin)
      3. capillary exchange
    4. more on homeostasis
  4. Defense systems
    1. general defenses
      1. skin and associated chemicals (lysozyme, acids) and bacteria (the resident flora)
      2. clot formation
        1. cascade of reactions ending with prothrombin to thrombin, which catalyzes the reaction fibrinogen to fibrin
        2. note that we also need to remove clots on cue; this is done through another cascade of reactions ending with conversion of plasminogen to plasmin through the action of tissue plasminogen activators
      3. inflammation response using histamine and the complement system
    2. directed (specific) defenses -- based on specific protein receptors that match elements of the invader
      1. white blood cells -- neutrophils, macrophages, and B and T lymphocytes; plasma cells
      2. chemicals -- antigens and antibodies, interleukins and lymphokines, MHC proteins
      3. cell-mediated response -- based on T-cell activity
        1. helper T-cells are activated by antigen-bearing macrophages, produce lymphokines
        2. lymphokines stimulate the production and response of cytotoxic T-cells
        3. only target cells with antigens and MHC I -- altered self cells
      4. antibody system
        1. antibodies produced by B lymphocytes in response to signals from helper T-cells
        2. antibodies bind to invader and target for complement and for killer T-cells
    3. applications
      1. blood-typing and Rh factors
      2. natural vs acquired immunity
      3. passive vs active acquired immunity
      4. autoimmunity
  5. Human death and disease
    1. major sources of mortality
      1. world-wide:  respiratory infections -- 7 million world; diarrheal disease -- 4.2 million;             TB -- 3.3 million; malaria -- 1 to 2 million; hepatitis -- 1 to 2 million
      2. US: cardiovascular diseases and cancer are far and away the leading causes of death; cerebrovascular disease and chronic pulmonary disease are next in line, tied with accidental death
    2. epidemiology
    3. infectious vs non-infectious disease
    4. susceptibility (genetic?) and risk factors (behavioral?)
      1. risk assessment
      2. major risk factors -- poor diet, tobacco, alcohol abuse, lack of exercise
    5. future prospects

Return to Dr. Nienow's HomePage

Continue with Unit 5