topic 2 - organisation

• FOOD TESTS:

  starch - iodine: orange to blue-black

  sugars - benedicts solution: blue to orange

  protein - buiret's reagent: blue to purple

  lipids - cold ethanol: colourless to cloudy
• What are cells considered in living organisms?

  Building blocks
• What is tissue composed of?

  A group of similar cells
• What defines an organ?

  A group of different tissues
• What is an organ system?

  A group of different organs
• What are the components of the digestion system?

  • Glands - pancreas & salivary juices
  • Stomach
  • Small intestine
• What do glands in the digestion system produce?

  • digestive juices
  • enzymes
• What does the stomach produce and why?


  • hydrochloric acid to kill bacteria & to provide the right pH for protease enzyme breakdown
• how does the stomach aid in digestion?


  • by churning food
• What is the function of the small intestine?

  • to absorb nutrients using villi
• why are products of digestion important?

  • they build new enzymes eg carbohydrates, lipids, and proteins
• what happens to some glucose produced during digestion?

  • it is used in respiration
• what role do enzymes play in reactions?

  • they catalyse reactions and break down molecules without being used up
• what is a catalyst?

  they speed up reactions and can be reused
• what is bile's function in digestion?


  • bile emulsifies fat droplets into smaller droplets
  • this increases surface area for faster enzyme breakdown
• how do enzymes relate to substrates?

  they are specific and fit like a lock and key
• what can cause enzymes to denature?


  • high temperature
  • pH
• what does lipase break down?

  lipids into fatty acids and glycerol
• where is lipase found?

  • small intestine
  • pancreatic fluid
• what does carbohydrase break down?

  • carbohydrates into sugars
• where is carbohydrase found?

  • saliva
  • pancreatic fluid
• what does protease break down?

  proteins into amino acids
• Where is protease found?

  Stomach and pancreatic fluid
• what does amylase break down?

  starch into glucose
• Where is amylase found?

  Saliva and pancreatic fluid
• what is the primary function of the heart?

  to pump blood around the body
• what type of circulatory system does the heart have?

  double circulatory system
• which ventricle pumps deoxygenated blood to the lungs?

  right ventricle - pulmonary artery
• what occurs in the lungs during blood circulation?

  gas exchange
• Which ventricle pumps oxygenated blood to the body?

  Left ventricle
• What happens simultaneously when the atria contract?

  They push blood into the ventricles
• How do the ventricles contribute to blood circulation?

  They contract to push blood out of the heart
• What is the role of the vena cava?

  Brings deoxygenated blood to the right atrium
• What does the pulmonary artery do?

  Takes deoxygenated blood to the lungs
• What is the function of the pulmonary vein?

  Takes oxygenated blood to the left atrium
• What does the aorta do?

  Takes oxygenated blood to the body
• What is the purpose of valves in the heart?

  Stops blood from flowing backwards
• Why is the muscle on the left side of the heart thicker?

  It pumps blood around the whole body
• Why does the heart need its own supply of oxygenated blood?

  To carry out respiration
• What are coronary arteries?

  Branch off aorta to supply heart