biology b3

• what is the order of organisation?

  cells, tissue, organ, organ system, organism.
• define cell


  Basic unit of life
• define tissue


  group of cells that are similar in structure and function
• define organ


  a structure made up of a group of tissues, working together to perform specific functions
• define organ system


  group of organs that work together to perform a specific function
• define organism


  organ systems working together to form a living thing
• mouth


  where digestion begins
• salivary glands


  makes saliva containing amylase
• trachea


  carries food to stomach
• stomach


  churns food

  releases protease which digests protein

  releases hydrochloric acid which kills pathogens
• liver


  makes bile
• gall bladder


  stores bile
• bile


  bile is alkaline to neutralise hydrochloric acid from the stomach, and emulsifies fat to form small droplets with a large surface area
• pancreas


  makes enzymes: amylase, lipase and protease
• small intestine


  where digested food is absorbed into the blood
• large intestine


  where water and minerals are absorbed into the blood
• amylase production sites


  salivary glands, pancreas, and small intestine
• lipase production sites


  Pancreas and small intestine
• protease production sites


  Stomach, pancreas, small intestine
• amylase reaction catalysed


  starch to sugars
• Lipase reaction catalysed


  Lipids to fatty acids and glycerol
• Protease reaction catalysed


  proteins to amino acids
• what do digestive enzymes do ?

  convert food into smaller more soluble molecules that can be absorbes into the bloodstream
• enzymes are ...


  large proteins that catalyse (speed up) reactions. Enzymes are not changed in the reactions they catalyse.
• explain the Lock + Key Theory


  1) the enemies active site is a specific shape to fit only one substrate

  2) the reaction will only happen if the enzyme (lock) and the substrate (key) are fit for each other

  3) At the active site, enzymes can break molecules down into

  smaller ones or bind small molecules together to form

  larger ones.

  4) When the products have been released, the enzyme's active

  site can accept another substrate molecule.

  
• What is the significance of optimum pH values for enzymes?

  Different enzymes have different optimum pH values to work well in environments with varying pH levels.
• How do enzymes adapt to different pH environments?

  Enzymes adapt by having specific optimum pH values that allow them to function effectively in environments with varying pH levels.
• what happens if the temperature is too high for an enzyme to work?

  it denatures/ stops working
• what happens at the optimum temperature?

  the reaction happens as fast as possible
• what happens at extreme temps/ph to an enzyme?

  the shape of an enzyme's active site can change.
• after denaturation the substrate...


  can no longer bind to the active site so the enzyme can't be catalysed.