other

• RESPIRATION is a chemical reaction which happens in all living cells, in which food (glucose) is broken down to release energy, usually combining it with oxygen
• Some animals do not need a respiratory system as they absorb oxygen through their skin (or membrane in cases of single celled organisms), as there aren't many cells to supply oxygen with as one of them are far away from the surface so diffusion is use. Lager animals have a respiratory system because if they absorbed oxygen through the skin , cells deep inside their body would die before the oxygen has a chance to reach them.
• Composition of exhaled and inhaled air

  A) 21%

  B) 16%

  C) 0.04%

  D) 4%

  E) 79%

  F) variable

  G) saturated

  H) 79%

  
• To test for the presence of CO2 you use the lime water experiment and a chemical that absorbs CO2 is NAOH
• Suggest a reason for colour change in the indicator

  • Yellow - pH decreases and becomes more acidic - CO+H20→H2CO2

  Suggest how the procedure could be adjusted so the amount of tar in 2 different cigarettes could be compared

  1 - Weigh cotton wool in beginning

  2 - Collect tar in cotton wool and weigh at end

  3 - Calculate decreases between stages 1 and 2 to find mass in tar

  4 - Repeat with another cigarette

  
• Breathing is the way some animals get the oxygen they need for respiration. Plants don't breathe. Many small animals can absorb oxygen through their body surface e.g. earthworms
• Respiration helps maintain body temp for mammals and birds
• life processes - movement, respiration, sensitivity, growth, reproduction, excretion and nutrition ( excretion and nutrition and both parts of digestion)
• more haemoglobin in the blood means more oxygen can be carried around the body (longer aerobic respiration)
• heart rate remains high after exercise stops so more oxygen can get to the heart quicker
• cells use the energy from respiration to carry out chemical reactions in the cell and combine small molecules to make larger ones
• Respiration is an exothermic reaction

  (releases heat)