Topic 4

• What are carbohydrates made up of?


  carbon, hydrogen, oxygen. Break dowm into simple sugars
• What are proteins made up of?

  carbon, hydrogen, oxygen, nitrogen, break down into amino acids
• What are lipids made from


  carbon, hydrogen, oxygen broken down into fatty acids and glycerol
• Test for glucose


  Blue Benedict's solution turns brick red after heating if present
• Test for protein?


  Buriet solution

  -Positive:Purple

  -Negative:No change
• Test for starch


  Iodine solution

  -Posotive:Blue black

  -Negative:Orange yellow
• Test for fats & lipids

  Ethanol and water, cloudy if present
• What are enzymes?


  biological catalysts
• What happens as temperature increases to enzymes


  Rate of reaction increases, until optimum temperature when enzymes start to denature as the active sight has changed so the substrate can't fit into the active sight
• practical: investigate how enzyme activity can be affected by changes in temperature

  Heat starch solution to set temperature and add amylase. One drop of iodine to each well and add amylase solution. Measure time taken to turn black. Repeat with different temperature
• pH effect on enzymes


  The optimum PH level is 7, if too high the amino acids are effected, the active sight changes shape and is denatured
• Practical- investigate PH


  Add amylase and starch to heated water at set temp. Add to a well filled with iodine. Add iodine every 10 seconds until the well stops turning black. Revised time taken and repeat with different PH solutions
• Practical: Energy from food


  Weigh a small amount of food and clamp it

  Add a set volume of water to a boiling tube

  Measure temp of water and set fire to the food

  Hold the food under the Bunsen until it goes out and relight it until the food won't catch fire anymore

  Measure temperature of water again then use equation

  Energy in food = mass of water x temp change x 4.2
• What are carbohydrates used for?

  energy and structure
• What are carbohydrates broken down by?

  amylase
• What are carbohydrates broken down into


  Maltose then glucose
• Where is amylase made?

  mouth, pancreas, small intestine
• What is protein used for

  growth and repair
• What is protein broken into

  amino acids
• What is protein broken down by

  protease
• Where is protase produced?


  Stomach

  Pancreas

  Small intestine
• What is fat broke down by

  Lipases
• What is fat broken into


  fatty acids and glycerol
• Where is lipase produced?

  Pancreas and small intestine