B3 - organisation and the digestive system

• What is the active site?

  Region of an enzyme where the chemical reaction takes place
• what is a carbohydrate?

  food group used as a source of energy
• what is a catalyst?


  chemical that speeds up a reaction
• what is denaturing?

  changing the shape of the enzyme’s active site
• what is a digestive enzyme?

  enzymes which speed up the process of digesting
• What is an enzyme?

  Protein which acts as a biological catalyst
• what is a lipid?

  other name for fats, needed as a source of energy
• what is a product?

  chemical made during a reaction
• What is protein?

  Food group needed for growth and repair
• What is a substrate?

  Other name for reactant, starting chemical in a reaction
• What is an example of a carbohydrate?

  amylase
• where is carbohydrate made in?

  salivary glands, pancreas and small intestine
• what is the job of carbohydrates?

  break down carbohydrates to simple sugar e.g. amylase breaks down starch to glucose
• Where are proteases made in?

  Stomach and pancreas
• what is the job of proteases?

  break down protein to amino acids
• Where is lipase made in?

  Pancreas (works in small intestine)
• What is the job of lipase?

  Break down lipids (fats) to glycerol and fatty acids
• is bile an enzyme?

  no
• where is bile made in?

  liver and stored in the gall bladder
• what is the job of bile?

  emulsifies lipids to increase surface area to increase the rate of lipid break down by lipase. changes pH to neutral for lipase to work
• What happens in the mouth?

  Where Food enters and digestion begins
• what do salivary glands produce?

  Produce saliva containing amylase
• what is the oesophagus?

  muscular tube which moves ingest
• What happens in the large intestine?

  Where water is reabsorbed
• what happens in the rectum?

  where faeces are stored
• What are the factors affecting enzyme action?

  Changes in temperature and pH as enzyme activity has an optimum temperature an pH
• what happens to enzyme activity if the temperature is too high?

  denature - enzyme changes shape - substrate no longer fits the active site
• what happens to enzyme activity if the pH is too low or too high?

  denature
• What is the chemical used in the test for sugar? Result?

  Add Benedict’s solution - turns brick red (or orange with less sugar)
• what is the chemical used in the test for protein? result?

  add biuret solution - turns purple
• What is the chemical used for the test for starch? Result?

  Add iodine - turns blue black