Biological molecules

• 2.7) What elements do proteins, carbohydrates and lipids have?

  Carbon, hydrogen and oxygen
• 2.8) carbohydrates are made of long chains of simple ——. The chemical name for these are —


  Sugars, monosaccharides
• 2.8) what is it called when two simple sugar molecules join together?

  Disaccharide
• 2.8) when lots of simple sugar molecules joined together they form a ——


  Polysaccharide
• 2.8) An example of a polysaccharide


  Starch and glycogen
• 2.8) What is the most common type of liquid in the body called? And what is it made of?

  Triglycerides and it is made up of 1x glycerol and 3x fatty bonds
• 2.8) proteins are made from —- chains of — —


  Long, amino acids
• 2.9) what does iodine test for? How do you carry out the test? What does the result show?

  Iodine test for STARCH - Carry out the test by placing food on a dropping tile and drop a few drops of iodine solution onto the food- positive result = turns from yellow to blue/black - negative result = Stays orange/yellow
• 2.9) Biurets solution test for? How do you carry out the test? What does the result show?

  Biurets solution tests for PROTEIN -carry out the test putting food in a test tube and add a few drops of the biuret solution- positive result = purple - negative result = blue
• 2.9) Benedicts test for? How do you carry out the test? What does the result show?

  tests for GLUCOSE - Carry out test by adding food to a test tube at the Benedict's solution and put in a water bath at 85° and leave for 5 to 10 mins-positive test= Green means a little amount is present orange means slightly more is present and red means a lot is present
• 2.9) what does ethanol test for?How do you carry out the test? What does the result show?

  tests for LIPIDS - to carry out test add food to a test tube and add a few drops of ethanol put a bung on the top of the tube and shake, pour the solution formed into a test tube containing water- positive result = if emulsion is present
• 2.10) what is a enzyme and HOW does it do it's function?

  An enzyme is a biological catalysts. It has an active site which is specific to a substrate. When an enzyme and substrate molecules collide the substrate binds to the active site of the enzyme, a substrate-enzyme complex is formed. Once the reaction has occurred products are formed but the enzyme is left unchanged
• 2.11) How does temperature affect enzymes?

  The optimum temperature of enzymes is 40° this is because it is the temperature of the human body. When the temperature is below 40° C enzymes have a low kinetic energy meaning less collisions happen, so the rate of reaction is slower. At the optimum temperature the enzymes have lots of kinetic energy so they move around more making them more likely to collide. Above 40° the active site of the enzymes become denatured this is a permanent change, Meaning a enzyme substrate complex cannot be formed meaning a reaction punker so no products can be formed
• 2.13) How does the pH affect the enzymes?

  The optimum temperature of the most enzymes is pH7, If the pH is too high or low on the bonds that hold the amino acids together can be disrupted/destroyed. This means that the active site will become denatured, it will change shape. So no substrate can bind, this reduces the rate of reaction