Chapter 1: Biological molecules

• adenosine triphosphate (ATP)


  a molecule that acts as the energy currency of cells formed from a molecule of ribose, adenine and three phosphate groups
• amino acid


  the monomers containing an amino group (NH2) a carboxyl group (COOH) and a variable R group that make up proteins
• benedict's test is used to for testing reducing sugars that produce a different colour based on the amount of reducing sugars present
• biuret test is used to test for protein - will go from blue to purple in presence of protein
• cellulose


  a polysaccharide made of beta glucose monomers that is used as a structural polysaccharide which provides strenght to a plant cell
• condensation reaction 


  a type of reaction that joins two molecules together with the formation of a chemical bond involving the elimination of a molecule of water
• deoxyribonucleic acid (DNA) 


  information storing molecule made up of deoxyribonucleic monomers joined together by phosphodiester bonds to form a double helix
• dipeptide 


  molecules formed by the condensation of two amino acids
• disaccharide 


  molecule formed by the condensation of two monosaccharides
• DNA helicase 


  an enzyme that breaks hydrogen bonds between two DNA strands in the DNA molecule that is going to be replicated
• DNA polymerase 


  an enzyme that catalyses the condensation reaction between the new nucleotides in the synthesis of the new DNA strand
• enzyme 


  a protein molecule that acts as a biological catalyst and increases rate of biochemical reaction
• glycogen 


  a highly branched polysaccharide made of alpha glucose monomers that is used as the main storage of energy in humand and animals
• glycosidic bond


  a bond between two monosaccharides formed in a condensation reaction
• heat capacity 


  the amount of energy needed to raise the temp of a substance by a specific amount
• hydrolysis 


  breaking a chemical bond between 2 molecules involving the use of water molecule
• induced fit model 


  a model of enzyme action that describes how enzymes undergo subtle confirmational changes to better fit the substrate
• iodine test 


  a biochemical test used to test for the presence of starch
• lactose 


  a disaccharide formed by condensation of a glucose molecule and a galactose molecule
• latent heat 


  the amount of energy needed for a substance to change state
• lipid emulsion test 


  a biochemical test that produced a cloudy emulsion when performed on lipids
• maltose 


  a disaccharide formed by the condensation of two glucose molecules
• metabolite 


  a molecule formed or used in metabolic reactions
• monomers 


  the smallest units from which bigger molecules are made
• monosaccharide 


  the individual sugar monomers from which larger carbohydrates are formed
• phospholipid 


  a type of lipid formed by the condensation of one molecule of glycerol, two molecules of fatty acid and a phosphate group
• polymers 


  molecules made of a large number of monomers joined together
• polypeptide 


  molecules formed by the condensation of many amino acids
• polysaccharide 


  molecules formed from the condensation of many monosaccharides
• primary structure 


  the individual sequence of amino acids in a protein
• quaternary structure 


  a structure only applicable to proteins with multiple polypeptide chains that describes the interactions of the different chains
• ribonucleic acid (RNA)


  a relatively short molecule made up of ribonucleotide monomers joined by phosphodiester bonds
• secondary structure


  the local interactions of the amino acids in the polypeptide chains (beta pleated or alpha helix)
• semi conservative replication 


  the production of 2 daughter DNA molecules from 1 DNA molecule which both contain one original DNA strand and one newly synthesised strand
• solvent 


  a substances in which other solutes dissolve in
• starch


  a polysaccharide made of alpha glucose monomers that is used as the main storage of energy in plants
• sucrose 


  a disaccharide formed by condensation of a glucose molecule and a fructose molecule
• tertiary structure 


  the way the whole protein folds to make a three dimensional structure
• triglyceride 


  a type of lipid formed by the condensation of one molecule of glycerol and three molecules of fatty acids
• property of starch and glycerol

  • insoluble - therefore doesnt affect water potential so water is not drawn in the cell by osmosis
  • large - does not diffuse out of cells
  • compact - lots can be stored in a small space
  • releases alpha glycose after hydrolysis - easily transported and readily used in respiration