2.2 Bio molecules

• Monomer


  A simple compound whose molecules can join together to form polymers
• Polymer


  A long molecule consisting of many similar or identical monomers linked together.
• condensation reaction


  when two hydroxyl groups align, a water molecule is removed leaving an oxygen atom to act as a bridge between monosaccharides.
• hydrolysis reaction


  splitting of a chemical bond by the addition of water, with the H+ going to one molecule and the OH- going to the other
• What elements make up lipids?

  Carbon, Hydrogen, Oxygen (CHO)
• general formula of lipids

  CH3(CH2)nCOOH
• triglyceride structure

  glycerol + 3 fatty acids

  
• Glycerol


  a three-carbon alcohol with a hydroxyl group attached to each carbon
• Lipid function

  long term energy storage, heat insulation, protection of organs
• Emulsion test

  Test for lipids. Mix the sample with ethanol and then add water. If a white cloudy emulsion forms then a lipid is present.
• Lipids are broken down into...

  fatty acids and glycerol
• proteins are made up of amino acids, which are linked together by peptide bonds making polypeptide chains.
• what elements make up proteins?

  carbon, hydrogen, oxygen, nitrogen, sometimes sulphur (CHONS)
• structural proteins make up components of body tissues such as muscles and skin ligaments.
• catalytic proteins are proteins that speed up biochemical reactions by lowering the activation energy (enzymes)
• signalling proteins are hormones and receptors that are involved in the communication between cells.
• immunological proteins are proteins that are produced by the immune system and are used to defend against pathogens (antibodies)
• the structure of an amino acid is a carboxyl group, an amino group, and a central R group

  
• the only difference between each amino acid is the nature of the R group.
• peptide bonds are formed between individual amino acids by condensation reactions, similar to carbohydrates.
• primary structure of a protein

  the sequence/order of the amino acids in the polypeptide chain.
• secondary structure of a protein

  occurs when the sequence of amino acids are linked by hydrogen bonds. the types of secondary structure are the alpha helix and the beta pleated sheet.

  
• tertiary structure of a protein

  occurs when certain attractions are present between alpha helices and beta pleated sheets. Contains 4 different bonds: disulphide bridges, hydrogen bonds, ionic bonds and hydrophobic/hydrophilic interactions.
• quaternary structure of a protein

  a protein consisting of more than one amino acid chain interlinked. Has the same bonds as tertiary.
• what causes denaturing of a protein?

  Heat, pH extremes, and certain chemicals can cause denaturation of proteins.
• How does protein denaturation work?

  when the bonds that maintain a protein's shape are broken. It is irreversible.
• test for proteins

  biuret test: Add sodium hydroxide (NaOH) followed by copper sulfate solution (CuSO4). If protein is present in the sample, the solution turns from blue to purple.
• Thin layer chromatography

  Quicker than paper chromatography, stationary phase (silica gel), mobile phase (solvent). Used to separate amino acids.
• retention factors (Rf) formula

  Rf = distance from origin to solute/distance from origin to solvent front

  (the answer is never greater than 1)
• globular proteins are soluble in water as the tertiary structure consists of the polar (hydrophilic) amino acids arranged on the outside and the nonpolar (hydrophobic) amino acids on the inside.
• examples of globular proteins are all hormones, enzymes and haemoglobin.
• a conjugated protein is a protein that has a non-protein component in its structure (eg haemoglobin with iron ions) As a prosthetic group, held by covalent bonds.
• prosthetic group: a non-protein component that forms a permanent part of a functioning molecule. also a cofactor bound by covalent bonds.
• what is the structure of haemoglobin?

  Quaternary structure, four polypeptide chains with two alpha-globin chains and two beta-globin chains. It contains four prosthetic groups thus four iron ions.
• what cant haemoglobin function without?


  the prosthetic groups
• function of haemoglobin: carry oxygen from lungs to body tissue cells. oxygen binds to each iron ion in each prosthetic group.
• keratin function: when a body part needs to be hard and stiff (nails, hooves, horns)
• keratin properties: waterproof, mechanical strength, barrier to infections.
• Elastin function: allows for living things to stretch and adapt their shape in terms of life processes.
• elastin properties: elasticity of skin, lungs, and blood vessels. expansion and returning to original state.