Chapter 3

• What is the level of organisation in an organism?


  Cells-tissues-organs-organ system
• What's the definition of a tissue?

  A group of similar cells
• What's the definition of an organ?

  A group of tissues performing a specific function
• Name the parts of the digestive system?

  
• What are simple sugars (carbohydrates)? How do you test for them?

  Carbohydrates that contain only one or two sugar units. They turn benedicts solution from blue to orange/ brick red when heated.
• What are complex carbohydrates (starch)? How do you test for them?

  Long chains of sugar units bonded together. They turn iodine solution form orange to blue/black
• What are protein molecules made of? How do you test for them?

  They are made of long chains of amino acids. They turn biuret solution from blue to purple
• What are lipids made out of? How do you test for them?


  They are made of 3 molecules of fatty acids bonded to a molecule of glycerol. If there is a cloudy white layer when ethanol is added, lipids are present

  
  

  note-sudan turns lipids red

  
• What are enzymes made of?

  Proteins
• What are catalysts?


  Substances that speed up chemical reactions without taking part (enzymes)
• What is the name of the theory that explains how enzymes work?

  The lock and key hypothesis

  
• How does temperature affect enzyme activity?


  Temperature increases enzyme activity. If the temperature is higher than the optimum temperature the enzyme will begin to denature.

  
• How does pH affect enzyme activity?

  Each enzyme has an optimal pH at which it can perform at its maximum rate. Too high or too low of a pH deviates the enzyme from its maximum rate.

  
• Explain how you would investigate the effect of temperature on time taken for amylase to digest starch?

  1)Heat 1cm of amylase solution

  2)mix the starch and amylase solution

  3)a sample is tested everyb30 seconds until all of the starch has been digested
• Why do we have to digest our food?

  To break down large molecules into smaller soluble ones so they can be absorbed by the blood
• During digestion, what is starch broken down into? What enzyme catalyses this breakdown?


  starch is broken down into sugar by amylase (a type of carbohydrase). Amylase is made in the salivary glands, the pancreas and the small intestine
• During digestion, what is protein broken down into? What enzyme catalyses this breakdown?


  Protein is broken down into amino acid by protease. Protease is made in the stomach, pancreas and small intestine
• During digestion, what is fat broken down into? What enzyme catalyses this breakdown?

  Fat is broken down into fatty acids and glycerol with lipase. Lipase is made in the pancreas and the small intestine
• Where is bile made and stored?

  Bile is made in the liver and stored in the gallbladder
• What jobs do bile have in digestion?

  Bile neutralises the acid from the stomach and emulsifies fat (breaks large fat droplets into smaller ones, which increase the surface area)
• What is the level of organisation in an organism?

  Cells-tissues-organs-organ system
• What's the definition of a tissue?

  A group of similar cells
• What's the definition of an organ?

  A group of tissues performing a specific function
• Name the parts of the digestive system?

  
• What are simple sugars (carbohydrates)? How do you test for them?

  Carbohydrates that contain only one or two sugar units. They turn benedicts solution from blue to orange/ brick red when heated.
• What are complex carbohydrates (starch)? How do you test for them?

  Long chains of sugar units bonded together. They turn iodine solution form orange to blue/black
• What are protein molecules made of? How do you test for them?

  They are made of long chains of amino acids. They turn biuret solution from blue to purple
• What are lipids made out of? How do you test for them?

  They are made of 3 molecules of fatty acids bonded to a molecule of glycerol. If there is a cloudy white layer when ethanol is added, lipids are present

  
  

  note-sudan turns lipids red

  
• What are enzymes made of?

  Proteins
• What are catalysts?


  Substances that speed up chemical reactions without taking part (enzymes)
• What is the name of the theory that explains how enzymes work?


  The lock and key hypothesis

  
• How does temperature affect enzyme activity?


  Temperature increases enzyme activity. If the temperature is higher than the optimum temperature the enzyme will begin to denature.

  
• How does pH affect enzyme activity?

  Each enzyme has an optimal pH at which it can perform at its maximum rate. Too high or too low of a pH deviates the enzyme from its maximum rate.

  
• Explain how you would investigate the effect of temperature on time taken for amylase to digest starch?

  1)Heat 1cm of amylase solution

  2)mix the starch and amylase solution

  3)a sample is tested everyb30 seconds until all of the starch has been digested
• Why do we have to digest our food?

  To break down large molecules into smaller soluble ones so they can be absorbed by the blood
• During digestion, what is starch broken down into? What enzyme catalyses this breakdown?

  starch is broken down into sugar by amylase (a type of carbohydrase). Amylase is made in the salivary glands, the pancreas and the small intestine
• During digestion, what is protein broken down into? What enzyme catalyses this breakdown?


  Protein is broken down into amino acid by protease. Protease is made in the stomach, pancreas and small intestine
• During digestion, what is fat broken down into? What enzyme catalyses this breakdown?

  Fat is broken down into fatty acids and glycerol with lipase. Lipase is made in the pancreas and the small intestine
• Where is bile made and stored?


  Bile is made in the liver and stored in the gallbladder
• What jobs do bile have in digestion?

  Bile neutralises the acid from the stomach and emulsifies fat (breaks large fat droplets into smaller ones, which increase the surface area)