Topic 1: biological molecules

• glycosidic bonds= chemical bonds which joins carbohydrates molecules together
• quarternary =level of protein structure which multiple polypeptide chains form together to make a protein
• non reducing sugars test=following a negative result with a benedicts test, a new sample is mixed with dilute HCL and slowly brought to a boil. this breaks the glycosidic bonds so the solution is neutralised with sodium hydrocarbonate and then tested with benedicts again
• primary structure= level of protein structure which shows the sequence of amino acids in a polypeptide
• induced fit model=a process where the active site changes its shape after substrate binding to improve affirmation and reduce activation energy.
• non competitive inhibitor= type of inhibitor which binds to the secondary binding site, changing the shape of the active site and preventing substrates binding
• proteins/amino acids test =biuret mixed with sample at room temp and will change from blue to purple which indicates that proteins is present
• competitive inhibitors= bind to active site and prevent substrate binding
• activation energy=energy required to start a reaction, enzyme lower the activation energy making the reaction more likely
• secondary structure= level of protein structure which shows the effects of hydrogen bonds in a polypeptide which creates alpha helix or beta pleated sheets
• peptide bonds=chemical bond which joins amino acids together
• ester bonds= hydrogen and carboxyl group, hydrolysis to remove water produces alcohol and carboxylic acid, which joins molecules together to form lipids
• hydrolysis= breaking down a chemical bond between two molecules using water as a catalyst
• teritory structure = level of protein structure that shows the effect of ionic bonds and disulphide bridges in a polypeptide, this includes only prosthetic(non proteins) groups in a protein
• starch = storage for carbohydrates found in plants

  • formed from alpha glucose
  • large insoluble molecule so it cant leave the cell
  • some branches for faster glucose release
• monosaccharides= carbohydrate molecules that cannot be broken down into simpler carbohydrates molecules , also called simple sugars e.g. glucose,fructose,galactose
• dissaccharides= a carbohydrate containing 2 monosaccharides joined by a glycosidic bond. e.g sucrose, lactose, maltose
• triglyceride= a lipid-containing three fatty acids and one glycerol, joined together by an ester bond

  function: energy store, thermal indicator, buoyancy, protection of vital organs and water proofing.
• cellulose=

  • carbohydrate which builds plant cell walls
  • formed by beta glucose
  • forms long straight chains linked together by hydrogen bonds
  • provides strength
• condensation= water molecules join together to form a hydrogen bond between the oxygen and hydrogen atoms and produces water as a product
• glycogen=

  • storage for carbohydrates found in animal
  • large insoluble molecules so it cant leave cells
  • highly branched for rapid glucose release
• phospholipid=a lipid consisting of 2 fatty acids, 1 phosphate and 1 glycerol, joined by ester bonds

  function: key component of cell membrane
• reducing sugars test=

  • test involves mixing the sample with benedicts solution then heating the solution up
  • coloured ppt means reducing sugars are present
  • greater colour change means higher concentration of reducing sugars, not which one is present
• emulsion test=shake sample with ethanol, then pour the solution slowly, if the mixture turns milky lipids are present
• starch test=at room temp with iodine and solution, iodine will change from orange to blue/black in the presence of starch
• high specific heat capacity =water can buffer changes in temperature
• strong surface conhesion=water has strong cohesion between molecules allowing water columns of water to form in the xylem and insects to move around on the surface of water
• solvent= other chemical can dissolve in water allowing reactions to occur
• hydrogen bonding= water molecule attracts another polar molecule by hydrogen bonds forming between them
• latent heat of vapourisation = water can provide a cooling effect through evaporation
• phosphodiester bond= phosphate group and deoxyribose sugar bond
• DNA helicase= breaks hydrogen bonds between DNA strands, untwists DNA strands between complementary base pairs
• RNA polymerase= synthesises mRNA using template strand as guide
• transcription= process where RNA is made from DNA
• ribosomes= site for protein synthesis
• messenger RNA (mRNA)= carries genetic information to ribosome
• semi conservative replication = DNA replication which produces a double stranded molecule consisting of one original and one newly synthesised strand
• restriction enzymes= cut DNA at specific sites
• Monomer


  Smaller units that join together to form larger molecules
• Polymer


  Molecules formed when many monomers join together