Biochemistry Part 1

• Biochemistry


  The study of the molecular basis of life or understanding life phenomena in chemical terms
• Antoine Lavoisier proposed that the combustion of a candle is similar to the respiration of animals, as both need O2


  1770's
• Vitalism


  The belief that the compounds found in living organisms (i.e., organic molecules) can only be produced by living organisms and could not be produced in the laboratory
• Friedrich Wöhler disproved the vitalism belief by synthesizing urea, an organic molecule and a waste product of animal metabolism, from ammonium cyanate, an inorganic molecule obtained from mineral (i.e., nonliving) sources


  1828
• Eduard Buchner's first demonstration of alcoholic fermentation in cell-free yeast extracts as the starting point for the birth of biochemistry


  1893
• Enzymes


  • They act as catalysts, increasing the rate of chemical reactions without themselves being consumed or permanently altered by the reaction
  • They increase reaction rates without altering the chemical equilibrium between reactants and products
• James Sumner showed that Enzymes are proteins


  1920s-1930s
• Transformation


  The process by which bacteria are capable of transferring genetic information

  
• Griffith's Transformation Experiment suggested that bacteria are capable of transferring genetic information through transformation


  1928

  
• Avery, MacLeod, and McCarty provided evidence that DNA is the genetic material


  1944
• Hershey and Chase Blender Experiment proved that DNA was the carrier of information


  1952
• James Watson and Francis Crick deduced the three-dimensional structure of DNA


  1953
• Central Dogma of Molecular Biology

  The normal flow of information from nucleic acid to protein is not reversible
• Life itself is constructed from non-living matter (i.e., atoms and elements)
• Elements that account for more than 97% of the weight of most organisms

  • Carbon
  • Hydrogen
  • Oxygen
  • Nitrogen
  • Phosphorus
  • Sulfur
• Water accounts for 60–95 percent of our living cells, and 55 percent of the water in the human body is in intracellular fluids
• Water


  • Acts as a transport medium across membranes, carrying substances into and out of cells
  • Helps maintain the temperature of the body
  • Acts as a solvent (carrying dissolved chemicals) in the digestive and waste excretion systems
• Water molecule


  • Hydrogen and Oxygen atoms form a covalent bond
  • Water molecules form hydrogen bonds
• Specific heat


  The amount of heat required to change the temperature of a gram of water 1° Celsius
• pH


  A measure of the acidity or basicity of the solution, calculated using the formula: pH = -log[H+]
• Even minor changes in hydrogen ion concentration can have direct consequences to a living organism
• Four major classes of Biological Macromolecules

  • Carbohydrates
  • Lipids
  • Proteins
  • Nucleic Acids