Lesson slides

• What substances need to be transported in an out of organisms?

  • Oxygen
  • Carbon dioxide
  • Water
  • Dissolved food molecules (e.g. glucose, amino acids)
  • Mineral ions
  • Urea
• Where does aerobic respiration occur?

  In the mitochondria of every cell in our body
• What happens during aerobic respiration?

  The oxygen that we inhale reacts with the glucose that we get from our food, this produces carbon dioxide and water
• What is produced during aerobic respiration?

  Carbon dioxide, water and heat
• What reacts in aerobic respiration?

  Glucose and oxygen
• Why do muscle cells have many mitochondria?

  Because they require more energy release for movement
• How does the oxygen move from the alveoli in the lungs into the blood in the capillaries?

  Diffusion from an area of high concentration(alveoli) to an area of low concentration(blood)
• What happens in the lungs?

  Oxygen diffuses into the blood and carbon dioxide diffuses out of the blood.
• What is gas exchange?

  When one gas is exchanged for the other
• Where does gas exchange take place?

  The alveoli
• What is diffusion?


  The random movement and spreading of particles. There is an overall movement of particles from regions of high concentration to regions of low concentration (down a concentration gradient)
• How are the alveoli adapted for gas exchange?

  To make sure a lot of particles diffuse quickly they have adaptations such as:

  • Thin walls of the blood vessels and aveolus
  • High concentration gradient(flow of blood)
  • Are moist
  • Large surface area
• How does the body get rid of waste carbon dioxide?

  Corbin dioxide diffuses down its concentration gradient from the cell in which it's made into the capillary
• Why are SA:V ratios significant in cells?

  As a cell gets bigger, it's SA:V ratio gets smaller. If the ratio is too small, then a cell can't get enough raw materials fast enough, so there is a limit to how big a cell can get
• What's the word equation for aerobic respiration?

  Glucose+oxygen→carbon dioxide+water
• Why is the wall of the alveolus and capillary one cell thick?

  To allow gases like oxygen and carbon dioxide to diffuse across successfully