respiration

• respiration is not...


  the same as breathing
• respiration


  The process by which cells break down simple food molecules to release the energy they contain
• all living things...

  respire
• where does respiration take place?

  mitochondria in cells
• what type of reaction is respiration?

  exothermic - it transfers energy to the environment
• respiration is used to...

  - build up larger molecules from smaller ones

  - allows muscles to contract to enable movement

  - keep the body temperature of mammals and birds steady in colder surroundings
• how is respiration used to build larger molecules?

  to build up larger molecules from smaller ones (like proteins from amino acids)
• how is respiration used to make muscles contract?


  in animals it is used to allow the muscles to contract so that they can move around
• how is respiration used to maintain body temperature?

  in mammals and birds the energy is used to keep their body temperature steady in colder surroundings (unlike other animals, mammals and birds keep their bodies constantly warm)
• metabolism


  all of the chemical reactions that occur within an organism
• what are chemical reactions in the body controlled by?

  enzymes
• what happens in enzymic reactions during metabolism?

  larger molecules are made from smaller ones OR larger molecules are broken down into smaller ones
• aerobic respiration needs...


  plenty of oxygen
• aerobic respiration


  respiration that requires oxygen
• is aerobic or anaerobic respiration more efficient?


  aerobic respiration is more efficient
• why is aerobic respiration more efficient?

  with oxygen, organisms can break down glucose all the way to carbon dioxide, meaning it releases much more energy
• aerobic respiration word equation

  glucose + oxygen → carbon dioxide + water (+ energy/ATP)
• aerobic respiration symbol equation

  C6H12O6 + 6O2 → 6CO2 + 6H2O
• anaerobic respiration is used if...

  there's not enough oxygen
• anaerobic respiration


  respiration in the absence of oxygen
• what does anaerobic respiration produce?

  lactic acid
• anaerobic respiration equation


  glucose → lactic acid (+ energy/ATP)
• anaerobic respiration in plants/yeast

  - produced ethanol and carbon dioxide instead of lactic acid

  - called fermentation in yeast cells

  - in bread-making, its the carbon dioxide from fermentation that makes the bread rise

  - in beer/wine-making, its the fermentation process that produces alcohol
• when you exercise, you respire...


  more
• during exercise, muscles need more energy from respiration to...


  contract
• during exercise, some muscles contract...


  more frequently to allow more movement
• when you exercise, breathing rate and breath volume...

  increases to get more oxygen into the blood
• when you exercise, heart rate...

  increases to get oxygenated blood around the body faster, removing carbon dioxide from the blood more quickly at the same time
• what happens when you do very vigorous exercise?

  your body is unable to supply oxygen to your muscles quickly enough, resulting in anaerobic respiration and a build up of lactic acid in the muscles
• what does lactic acid build up in the muscles result in?

  muscle fatigue and soreness
• anaerobic respiration leads to...

  oxygen debt
• oxygen debt


  the amount of oxygen required by the body to react with the build up of lactic acid and remove it from the cells
• oxygen reacts with lactic acid to form...

  Harmless carbon dioxide and water
• why do you breathe harder after exercise?

  to get more oxygen into your blood, making up for the oxygen that did not get to your muscles in time because the heart lungs and blood could not meet the demand
• pulse and breathing rate remain high whilst there are high levels of...

  lactic acid and carbon dioxide
• another way the body copes with high level of lactic acid is by...

  having the blood that enters the muscles transport the lactic acid into the liver, where it is converted back into glucose