Biology 2

• what is a tissue made up of ? 


  cells
• what are tissues organised into? 


  organs
• what are organs organised into? 


  organ systems
• what are enzymes? 


  control chemical reactions

  biological catalyst
• what is a catalyst? 


  a substance which increases the speed of a reaction without being changed or used up in the reaction
• what happenns if an enzyme gets to hot? 


  the bonds holding the enzyme together break, changing the shape of the enzymes active site therefore the substrate won’t fit anymore

  (the enzyme is denatured)
• how do u calculate the rate of reaction?


  1000/time
• what do digestive enzymes break down?


  starch, proteins and fats
• what do digestive enzymes break big molecules like starch proteins and fats down into?


  sugars (glucose and maltose)

  amino acids

  glycerol

  fatty acids
• why can smaller molecules pass easier through the walls of the digestive system? 


  they are smaller and soluble therefore can be absorbed into the blood stream
• where is amylase found? 


  in the salivary glands

  the pancreas

  the small intestine
• what is amylase and what does it break down? 


  amylase is a carbohydrase that breaks down starch
• what does amylase break down starch into? 


  maltose
• what is a protease?

  a carbohydrate that converts proteins into amino acids
• where are proteases found ? 


  the stomach

  the pancreas

  the small intestine
• what is lipase?


  a carbohydrase which converts lipids into glycerol and fatty acids
• where is lipase found? 


  the pancreas

  the small intestine
• what is the function of bile? 


  neutralises the stomach acid and emulsifies fats
• explain the food test practical. 


  get a piece of food and break it up using a pestle and mortar

  transfer the ground up food to a beaker and add some distilled water

  give the mixture a good stir with a glass rod to dissolve some of the food

  filter the solution using a funnel lined with filter paper to get rid of solid bits of food
• what is the test for sugars? 


  test using benedict’s solution

  result blue to brick red
• what is the test for starch? 


  test using iodine solution

  result browny orange to blue black
• what is the test for proteins? 


  test using biutets solution

  result blue to purple
• what is the test for lipids? 


  test using sudan 111

  result a top layer of red
• what are the lungs surrounded by? 


  pleural membrane
• where does the air we breath in go through? 


  the trachea then splits off into two tubes (the bronchi) going to each lung
• what does the bronchi split into? 


  smaller tubes called bronchioles
• what is at the end of bronchioles? 


  small bags called alveoli where gas exchange takes place
• what does alveoli do? 


  carry out gas exchange in the body

  diffuse oxgen out of the alveoli (high concentration) into the blood containing lots of co2 (low concentration)

  and the other way around
• how do you calculate breaths per minute? 


  number of breaths/ number of minutes
• what are the function of valves? 


  make sure blood is flowing in the right direction - they prevent it flowing backwards
• which side of the heart is oxygenated? 


  left side
• explain how blood flows through the heart

  deoxygenated blood flows into the right atrium through the vena cava it then flows into the right ventricle and is pushed using the valves into the pulmonary artery to the lungs.

  from the longs it reenters the heart oxygenated through the pulmonary vein into the left atrium and is then pumped into the left ventricle and out of the aorta into the blood stream
• what are the three types of blood vessel?


  arteries

  capillieries

  veins
• what is the function of a vein?


  carry blood to the heart
• what is the function of capillieries?


  involves in the exchange of materials at the tissues
• what are arteries?


  Blood vessels that carry oxygenated blood away from the heart to the rest of the body.
• how do you calculate the rate of blood flow?


  volume of blood/number of minutes
• what 4 main things are in the blood?

  red blood cells

  white blood cells

  platelets

  plasma
• what do red blood cells do?


  Transport oxygen
• what do white blood cells do?


  defend against infection