Biological Molecules

• Carbohydrates

  Carbon, Hydrogen, Oxygen
• Proteins

  Carbon, Hydrogen, Oxygen, Nitrogen
• Lipids (Fats and Oils)

  Carbon, Hydrogen, Oxygen
• Carbohydrates


  • Includes starch and glycogen (simple sugars) where starch is a chain of glucose
• Proteins


  • Chains of amino acids, each with a unique function
• Lipids


  • Fats and oils have fatty acids and glycerol; essential for energy and membrane structure
• Test for glucose


  Use benedict's solution in a hot water bath (blue before, positive turns brick-red)
• Detect starch


  Use iodine (brown before, positive turns blue-black)
• Confirm proteins


  Use Biuret solution (blue before, positive turns purple)
• Identify fats


  Use ethanol and water (colourless before, positive turns cloudy)
• Enzymes

  Biological catalysts that speed up chemical reactions in living organisms
• Temperature affects enzyme activity

  Too high temperatures can alter the enzyme's shape (being denatured), impacting function. Too low temperatures will decrease energy and hence decrease productivity
• Enzyme activity and temperature


  There is an optimal temperature, as enzymes can react faster (up to a point) at higher temperatures
• Investigate how enzyme activity is affected by changes in temperature


  At a higher temperature, enzymes will work faster, yet too high of a temperature and they will not react at all
• Changes in pH

  Will increase or decrease the productivity, and at too high or low pH it will become denatured
• Enzyme function and pH

  There is an optimal pH in which the enzyme works best, based on where the enzyme works in the body
• Investigate how enzyme activity is affected by changes in pH


  Put a drop of iodine on a spotting tile, and mix amylase and buffer solution of a certain pH in a test tube. Add the starch, and every 10 seconds put a drop into one of the spots. Test for multiple pHs. Result: An enzyme will have an optimal pH, and it will work best when closest to that pH