Biological Molecules

• What are the 2 carbohydrate groups?


  - Polymers

  - Monomers
• Polymers


  Large, complex molecules composed of long chains of monomers joined together
• Monomers


  Small molecules
• What are the elements in carbohydrates?


  - Carbon

  - Hydrogen

  - Oxygen
• What are some examples of sugars?


  - Glucose

  - Fructose

  - Lactose

  - Sucrose

  
  

  They are all edible and contain starch
• Where is fructose found?

  Fruit
• Where is lactose found?


  Dairy
• Where is sucrose found?

  Plants
• What is used to test for glucose?


  Benedict's solution
• What colour is Benedict's solution if is not present?

  It stays blue
• What colour is Benedict's solution if is present?


  Orange/Brick red
• What is the method for testing for glucose?


  - Add Benedict's solution to the 5ml food sample

  - Heat the mixture in a boiling tube in a water bath

  - The colour of the solution will turn orange/brick red if glucose is present
• Startch


  Insoluble and stored in plants
• Cellulose


  Insoluble and is found in plant cell walls
• Glycogen


  Insoluble and stored in fungi and animals
• What so you need to test for starch?

  Iodine solution
• What colour is iodine solution if starch is present?

  Blue/black
• What are proteins made of?

  Amino acids
• What are amino acids made of?

  Large polymers
• What elements to proteins contain?


  - Carbon

  - Hydrogen

  - Oxygen

  - Nitrogen

  - Sometimes sulphur
• Why do we need proteins?

  Proteins are needed by our body for the growth and repair of cells
• What are some good sources of proteins?


  - Dairy foods (cheese, yogurt and milk)

  - Meat

  - Fish

  - Lentils
• What is used to test for proteins?

  Biuret solution
• Method for testing for proteins


  - Grind up the food sample using a pestle ad mortar

  - Add some water to make it a paste

  - Add the Biuret solution
• What colour does biuret solution turn if proteins are present?

  Purple
• What is biuret solution made of?


  - Copper sulphate

  - Sodium hydroxide
• What are lipids commonly called?


  - Fats

  - Oils
• What are fats?


  Solids at room temperature (Butter)
• What are oils?


  Liquids at room temperature (Olive oil)
• What are elements are lipids made out of?

  - Carbon

  - Hydrogen

  - Oxygen
• What are lipids made from?


  - Fatty acids

  - Glycerol
• What do you use to see if lipids are present?


  Ethanol
• What is the test for lipids called?

  Emulsion test
• Method for telling if there are lipids present


  - Grind up the food sample and if it is dry add some water to it

  - Place it into the test tube

  - Shake the food with ethanol for 1 min in a test tube with a bung in the top

  - Add water to the test tube

  -If lipids are present there will be a white milky emulstion
• What are enzymes?


  Enzymes are biological catalysts produced by living things
• What do enzymes do?


  - Enzymes speed up the chemical reaction, without enzymes chemical reactions would be too slow and we would die

  - Enzymes are needed for everything for example digestion, respiration and photosynthesis
• What are enzymes made of?

  Proteins
• How do enzymes work?

  Enzymes work by lowering the energy needed for a reaction to happen
• What is the problem with enzymes?


  - Enzymes are very specific

  - They will only speed up 1 type of reaction

  - This is because each type of enzyme has a specially shaped active site to fit on a substrate
• Catalyst


  A substance which changes the chemical reaction without being changed itself