respiration

• when we breathe in and out we ventilate our lungs with air
• respiration is a crucial chemical reaction which has to take place in every cell to release energy
• breathing gets oxygen into our bloodstream and gets rid of carbon dioxide. this ventilation is called inhalation
• glucose + oxygen ---> energy +carbon dioxide + water
• glucose is chemically smouldered with oxygen in the mitochondria within the cytoplasm
• the energy released in respiration is used to:

  allow muscles to move

  pump important chemicals in and out of cells

  transmit impulses along nerve cells

  make new cells

  keep cells warm
• carbon dioxide is toxic so cells have to expel this molecule instantaneously before it kills them
• respiration takes place in plant cells 24/7
• respiration takes place in animal cells 24/7
• photosynthesis takes place in plant cells only when light is available
• photosynthesis never takes place in animal cells
• the air we breathe in is called atmospheric or inhaled air
• the air we breathe out is called exhaled or expired air
• nitrogen- difference in exhaled sir compared to atmospheric air- no change because nitrogen is not used or produced
• oxygen - difference in exhaled air compared to atmospheric air- decrease in exhlaled air because oxygen is used by cells
• carbon dioxide - difference in exhaled air compared to atmospheric air - increase in exhaled air because carbon dioxide is produced by cells
• water vapour - difference in exhaled air compared to atmospheric air - increase in exhaled air because water is produced by cells
• nitrogen in inhaled air = 78

  exhaled air = 78
• oxygen in inhaled air = 21

  exhaled air = 16
• carbon dioxide in inhaled air = 0.03

  exhaled air = 4
• water vapour in inhaled air = variable

  exhaled air = always high
• when i blew into indicator it changed from colourless to cloudy. this shows that i exhale the gas carbon dioxide. my cells produce this gas as a waste product when they carry out the process of respiration
• limewater (colour - milky) detects an increase in carbon dioxide
• hydrogen carbonate indicator (berry red- yellow) detects an increase in carbon dioxide
• cobalt chloride paper (blue - pink) detects water molecules
• lime water = colourless + CO2 ---> cloudy
• hydrogen carbonate indicator = berry red + CO2 ---> yellow
• cobalt chloride paper = blue + H20 ---> pink
• we breathe by changing the size of our chest cavity using out diaphragm and intercostal muscles
• the bell jar model of the thorax;

  bell jar represents rib cage

  air space represents chest cavity

  glass tube represents trachea

  balloons represent lungs

  rubber sheet represents diaphragm
• bell jar model of thorax=

  large volume = small pressure

  small volume = large pressure
• intercostal muscles (inhaling) contract pulling the ribcage up and out
• intercostal muscles (exhaling) relax causing the ribcage to fall down and in
• diaphragm (inhaling) contracts pulling diaphragm flat
• diaphragm (exhlaing) relaxes returning it to a dome shape
• thorax volume (inhaling) increases
• thorax volume (exhaling) decreases
• thorax pressure (inhaling) increases
• thorax pressure (exhaling) increases
• air flow (inhaling) air sucked into lungs