Biological Molecules Topic 1

• Monomers are smaller units which can create larger molecules and the polymers are made from lots of monomers which are bonded together
• Examples of monomers and polymers

  • Glucose (monomer)
  • Amino acids (monomers)
  • Nucleotides (monomers)
  • Starch (polymer)
  • Cellulose (polymer)
  • Glycogen (polymer)
  • Proteins (polymer)
  • DNA/RNA (polymer)
• Condensation reaction to create polymers


  1. Joining two molecules together

  2. Creating a chemical bond

  3. Removing water
• Hydrolysis reaction to break apart polymers

  1. Breaking a chemical bond between two molecules

  2. Involves the use of water
• Monosaccharide


  One sugar unit
• Disaccharide


  Two sugar units joined together
• Polysaccharide


  Many sugar units joined together
• Monosaccharides


  • Glucose
  • Fructose
  • Galactose
• Disaccharides


  • Sucrose
  • Maltose
  • Lactose
• Polysaccharides


  • Starch
  • Cellulose
  • Glycogen
• Alpha glucose


  Hydrogen atom on top, hydroxyl group on bottom of carbon 1
• Beta glucose


  Hydroxyl group on top, hydrogen atom on bottom of carbon 1
• Glycosidic bond


  Chemical bond that forms between two monosaccharides to create a disaccharide
• Maltose


  Glucose + Glucose
• Lactose


  Glucose + Galactose
• Sucrose


  Glucose + Fructose
• Starch


  • Stored in plants as a source of glucose
  • Made from alpha glucose
• Cellulose


  • Structural component in plant cell walls
  • Made from beta glucose
• Glycogen


  • Stored in animals as a source of glucose
  • Made from alpha glucose
• Starch and glycogen have 1-4 and 1-6 glycosidic bonds, cellulose has only 1-4 glycosidic bonds</b>
• Amylose


  Unbranched polymer in starch
• Amylopectin


  Branched polymer in starch
• Carbohydrates are large and insoluble, so they don't affect water potential or osmosis
• Cellulose


  • Long straight chains held together by hydrogen bonds, providing structural strength
• Glycogen


  • Highly branched, allows more rapid hydrolysis to glucose
• Triglycerides


  Lipid with 3 fatty acid chains attached to a glycerol molecule
• Phospholipids


  Lipid with 2 fatty acid chains and a phosphate group attached to a glycerol molecule
• Formation of triglycerides


  3 condensation reactions, 3 ester bonds formed, 3 water molecules removed
• Triglycerides


  • High ratio of energy-storing C-H bonds, can act as metabolic water source, do not affect water potential
• Phospholipids


  • Hydrophilic head, hydrophobic tails, can form bilayers
• Amino acid


  Monomer that makes up proteins, has central carbon, hydrogen, amine group, carboxyl group, and variable R group
• Formation of dipeptide


  Condensation reaction, water removed, peptide bond formed
• Formation of polypeptide


  Multiple condensation reactions, multiple peptide bonds formed
• Primary structure


  Order/sequence of amino acids in a polypeptide chain
• Secondary structure


  Folding of polypeptide chain into alpha helix or beta pleated sheet, held by hydrogen bonds
• Tertiary structure


  Further folding of polypeptide chain into unique 3D shape, held by ionic, hydrogen, and disulfide bonds
• Quaternary structure


  Protein made up of more than one polypeptide chain
• Enzymes


  • Proteins in tertiary structure that catalyze reactions by lowering activation energy
  • Each enzyme is specific to one reaction due to the shape of the active site
• Induced fit model


  Enzyme active site slightly changes shape to mold around the substrate, putting strain on bonds to lower activation energy
• Active site


  Complementary in shape to a particular substrate