general

• Biochemistry of Cells
• Americans consume an average of 140 pounds of sugar per person per year
• Cellulose, found in plant cell walls, is the most abundant organic compound on Earth
• A typical cell in your body has about 2 meters of DNA
• A typical cow produces over 200 pounds of methane gas each year
• About 60-90 percent of an organism is water
• Water is used in most reactions in the body
• Water


  The universal solvent
• Water properties


  • Polarity
  • Cohesiveness
  • Adhesiveness
  • Surface Tension
• Although a cell is mostly water, the rest of the cell consists mostly of carbon-based molecules
• Organic chemistry is the study of carbon compounds
• Carbon


  • It has four electrons in an outer shell that holds eight
  • Carbon can share its electrons with other atoms to form up to four covalent bonds
• Hydrocarbons


  The simplest carbon compounds that contain only carbon and hydrogen atoms
• What carbon can do

  • Attach to other carbons
  • Form an endless diversity of carbon skeletons

  
• The hydrocarbons of fat molecules provide energy for our bodies

  
• Each type of organic molecule has a unique three-dimensional shape that determines its function in an organism

  
• Functional groups


  • Groups of atoms that give properties to the compounds to which they attach
  • Can gain or lose electrons
• Polymers


  Large molecules built from smaller molecules called monomers
• Examples of polymers


  • Proteins
  • Lipids
  • Carbohydrates
  • Nucleic Acids
• Polymers are made by stringing together many smaller molecules called monomers
• Linking monomers


  1. Condensation or dehydration synthesis (removing a molecule of water)

  2. Cells link monomers this way
• Breaking down polymers


  1. Hydrolysis (adding a molecule of water)

  2. Cells break down macromolecules this way
• Categories of large molecules in cells

  • Carbohydrates
  • Lipids
  • Proteins
  • Nucleic Acids
• Monosaccharides


  • Called simple sugars
  • Include glucose, fructose, & galactose
  • Have the same chemical, but different structural formulas
• Monosaccharides


  • Glucose
  • Fructose
  • Galactose
• Isomers


  Glucose & fructose are isomers because they have different structures but the same chemical formula
• In aqueous (watery) solutions, monosaccharides form ring structures
• Monosaccharides


  The main fuel that cells use for cellular work
• Disaccharides


  Double sugars made by joining two monosaccharides and removing a water molecule (condensation)
• Common disaccharides


  • Sucrose (table sugar)
  • Lactose (Milk Sugar)
  • Maltose (Grain sugar)
• Polysaccharides


  Complex carbohydrates composed of many sugar monomers linked together
• Examples of polysaccharides


  • Starch
  • Glycogen
  • Cellulose
• Starch


  A polysaccharide in plants that plant cells store for energy
• Glycogen


  A polysaccharide in animals that animals store excess sugar in the form of

  
• Cellulose


  • The most abundant organic compound on Earth
  • Forms cable-like fibrils in the tough walls that enclose plants
  • A major component of wood
  • Also known as dietary fiber
• Most animals cannot derive nutrition from fiber, but they have bacteria in their digestive tracts that can break down cellulose
• Simple sugars and double sugars

  • Dissolve readily in water
  • Are hydrophilic, or "water-loving"
• Lipids


  • Hydrophobic - "water fearing"
  • Includes fats, waxes, steroids, & oils
  • Do NOT mix with water
• Function of lipids


  Store energy, help to insulate the body, and cushion and protect organs
• Unsaturated fatty acids


  Have less than the maximum number of hydrogens bonded to the carbons (a double bond between carbons)