Biology T1

• 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 enzymes to attach and hydrolyse it back 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 to C atoms
  • Can act as a metabolic water source when oxidised
  • Do not affect water potential or osmosis
• Phospholipids


  • Hydrophilic head, hydrophobic tails
  • Can form a bilayer in water
• Amino acid


  Monomer that makes up proteins, has a central carbon, 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 of proteins

  The sequence of amino acids in the polypeptide chain
• Secondary structure of proteins

  The folding of the polypeptide chain into alpha helices or beta pleated sheets, held by hydrogen bonds
• Tertiary structure of proteins


  The further folding of the polypeptide chain into a unique 3D shape, held by ionic, hydrogen and disulfide bonds
• Quaternary structure of proteins

  When a protein is made up of more than one polypeptide chain
• Enzymes


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


  The active site of an enzyme slightly changes shape to mould around the substrate, putting strain on the substrate bonds
• Active site


  Complementary in shape to a particular substrate