topic 1

• carbohydrates- respiratory substrates in cells, structural components in plasma membranes and cell walls
• lipids


  forms bilayers in plasma membrane ; some are hormones and respiratory substrates
• proteins 


  components of many cellular structures ; enzymes; chemical messengers; blood components
• nucleic acids 


  forms the genetic code for protein production
• monomers 


  small units that make up larger molecules
• polymers 


  large molecules made up of a large number of monomers
• monomers are joined by condensation reaction 


  elimination of water molecules
• bonds between polymers can be broken down through hydrolysis


  using a water molecule
• carbohydrates-

  component molecules -monosaccharides eg glucose, fructose, galactose

  polysaccharides - glycogen found in animal cells

  cellulose found in plant cells

  starch found in plant cells

  bonds- glycosidic bond formed by a condensation reaction between monomers

  biochem test- benedict's solution test for reducing and non reducing sugars

  iodine for starch
• lipids

  component molecules - glycerol and fatty acids (saturated or unsaturated)

  triglycerides are made up of three fatty acids (r-cooh) and one glycerol

  phospholipids are made of two fatty acids and a phosphate group and one glycerol


  Ester bonds formed by a condensation reaction between glycerol and three fatty acids molecules in triglycerides

  emulsions test- turns milky white emulsion in solution when a lipid is present
• triglycerides 


  are insoluble in water as they are non polar
• phospholipids 


  has hydrophilic phosphate heads and hydrophobic fatty acids
• saturated - doesnt have a double bond in the carbon chain 


  unsaturated - has a double bond in the carbon chain
• glucose +glucose = maltose 


  glucose + fructose = sucrose

  glucose+ lactose =lactose
• glycogen and starch and polymers are made from condensation reactions with alpha glucose molecules 


  cellulose is a polymers are made from condensation reactions with beta glucose molecules
• Proteins made up of monomers are called amino acids

  fibrous proteins form long parallel chains and have structural functions such as collagen