Biology topic 5

• What is respiration

  A series of chemical reactions that continually release energy
• What type of reaction is respiration

  Exothermic
• What is the word equation for aerobic respiration

  glucose+oxygen—->carbon dioxide and water
• When does anaerobic respiration occur

  Not enough oxygen is available eg during exercise in human muscles which causes the build up of lactic acid
• What is the word equation for anaerobic respiration

  Glucose—->lactic acid+energy
• What is the word equation for anaerobic respiration produced by yeast

  Glucose——->alcohol+carbon dioxide
• What does the trachea do

  Supported by cartilage to prevent it collapsing
• What does the bronchus do

  it is supported by cartilage
• What does pleural membrane?

  Reduces friction during breathing
• Where does gas exchange take place in humans

  Alveoli
• What does air enter

  Nasal cavity
• What happens after air enters nasal cavity

  Warmed and filtered before continuing into The lunge
• What diffuses in to the blood

  Oxygen
• What diffuses from the blood

  Carbon dioxide
• How is spongy mesophyll of a leaf adapted for gas exchange

  •they increase the surface area

  •moist thin walls helps gases to dissolve
• What happens in the process of breathing

  •As diaphragm moves down, volume inside glass jar increases

  •this causes pressure inside to decrease

  •this causes air to enter lungs until pressure inside and outside the bell jar is equal
• what happens to lungs when inhaling?

  •Intercostal muscles contract,ribs move up and out

  •diaphragm contracts and moves down

  •Volume of thorax increases causing pressure to decrease. Air enters the lungs because lung pressure falls below atmospheric pressure
• What happens to the lungs when exhaling


  Intercostal muscles relax, ribs move down and in

  •Diaphragm relaxes and returns back to its normal shape

  •Volume of thorax decreases raising the pressure which forces air out of lungs
• effect of exercise on breathing

  Increased exercise means that muscle cells will use more oxygen from blood and pass more carbon dioxide into the blood
• Where is the respiratory system in humans

  Thorax
• What are lungs represented by in the bell jar model

  Balloons
• What is the diaphragm represented by in bell jar lung model

  Thin sheet of rubber
• How does an alveoli’s large surface area adapt to its function

  Each alveoli has a large surface area, together these make a gas exchange surface of many squared metres
• How does thin walls with short diffusion distances help alveoli’s be adapted for their function

  There is only a short diffusion distance for gases involved
• How do the alveoli’s moist walls help it be adapted for its function

  They help gases pass through respiratory surfaces because gases dissolve in the moisture
• How does permeable surfaces help an alveoli adapt to its function

  gases Can pass through
• How does a good blood supply help an alveoli adapt to its function

  Alveoli’s are surrounded by capillaries to ensure that any oxygen diffusing through is carried around the body
• How does a diffusion gradient help an alveoli be adapted for its function

  It encourages oxygen to diffuse into the blood and carbon dioxide to diffuse from the blood
• In humans where does carbon dioxide diffuse from and where does it go

  From the blood into alveolo
• Describe ways aerobic respiration differs from anaerobic respiration in yeast

  Alcohol- Produced by anaerobic

  Water- Produced by aerobic

  Energy- Aerobic produces more than anerobic
• What can energy produced from respiration be used for?

  Movement, heating the body or growth