Topic 2

• Describe the lock and key model 


  Substrate has to fit perfectly to the enzymes active site
• What is the definition of an organ system ?

  A group of organs that work together to perform a specific function e.g digestive system or circulatory system
• What is an organ ? 


  A group of different tissues that work together to perform a specific function
• Tissue 


  A group of similar cells that work together to carry out a function
• What is an organelle ? 


  A sub cellular structure e.g nucleus
• What are the levels of organisation ?

  Organelles

  Cells

  Tissues

  Organs

  Organ system

  Organisms
• What is an enzyme ?

  A catalyst made by living organisms
• What is a catalyst? 


  A substance that increases the rate of a reaction without being changed or used up in the process
• What makes up an organism? 


  Multiple organ systems that work together
• What are the 3 types of biological molecules ? 


  Carbohydrates, Proteins , Lipids
• What are carbohydrates made up of ?

  Carbon,hydrogen and oxygen
• Small carbohydrates are also known as 


  Simple sugars (glucose)

  Or monomers
• Where are carbohydrates broken down ? (polymers to monomers) 


  Small intestine and mouth
• What are proteins made up of ? 


  Long chains of amino acids
• What are amino acids made up of ? 


  Carbon,hydrogen,oxygen and nitrogen
• Where are proteins broken down ? 


  Small intestine and stomach
• What are lipids ? 


  Fats and oils
• what are lipids made up of ?

  Carbon,hydrogen and oxygen
• Where are lipids broken down ? 


  Small intestine
• Lipids contain a single glycerol molecule attached to 3 fatty acid molecules
• What enzyme breaks down carbohydrates (main types starch) ?

  Amylase
• What does starch break down into ?

  Maltose
• where is amylase made 


  Salivary glands, pancreas , small intestine
• What enzyme break down proteins ? 


  Protease
• Proteins break down into 


  Amino acids
• What enzyme breaks down lipids ?

  Lipases
• What enzyme breaks down lipids ?

  Lipases
• What do lipids break down into ? 


  Glycerol and fatty acids
• Where are lipases produced ? 


  Pancreas and small intestine
• How does bile help break down lipids ?

  Emulsifies them , increasing the surface area for lipases to break down
• catalyst 


  A substance that increases the speed of a chemical reaction without being used up or changed in the process
• What are enzymes also known as ? 


  Biological catalysts
• What is the active site on an enzyme ? 


  The special region that binds to a substrate (reactant)
• Describe the lock and key model 


  Scientists believed that in order for an enzyme to catalyse a reaction the substrate had to fit perfectly to the the active site
• Describe the induced fit model 


  In order for an enzyme to catalyse a reaction, the enzymes active site actually changes slightly as it binds to the substrate
• What is the purpose of the Benedict's test?

  To test for reducing sugars
• How many types of sugars are there ?

  Two types: Reducing and Non-reducing
• What does the Benedict's test specifically test for?

  Reducing sugars
• How much solution should be transferred into the test tube for the Benedict's test?

  5 cm³
• At what temperature should the water bath be prepared for the Benedict's test?

  75°C