Aerobic respiration

• What is respiration


  The way cells liberate the energy stored in food
• Where does respiration take place?

  Mitochondria
• Aerobic respiration word equation

  Glucose + Oxygen --- Carbon dioxide + Water (Energy)
• Aerobic respiration chemical equation

  C6 H12 O6 +6O2 --- 6CO2 + 6H2O
• For every one molecule of glucose...

  6 oxygen molecules are present.

  • This produces 6 carbon dioxide molecules and 6 water molecules
• What happens when we exercise?

  • Muscles require more energy - extra contractions
  • Aerobic respiration increases
  • Cells loose oxygen and glucose
  • Heart beats faster to ensure more oxygenated blood reaches cells
  • Blood also brings increased supplies of glucose and takes away the carbon dioxide and excess water
  • Breathing rate increases - the more you breathe in and out, the more oxygen for the cells and greater removal of waste products
  • If the exercise is so demanding that oxygen is depleted, anaerobic respiration takes place
• Skydiver QER (1-2)

  1. Initial Freefall (First few seconds):

  • Forces acting: The skydiver is initially in freefall, where gravity pulls them downwards, and air resistance is minimal.
  • Speed: The skydiver accelerates due to gravity, causing their velocity to increase.
  • Key Point: The air resistance is low at this stage, so the skydiver accelerates faster, with an increasing velocity.

  2. Increasing Air Resistance:

  • Forces acting: As the speed increases, the air resistance also increases.
  • Effect on motion: The skydiver's acceleration starts to decrease because the upward force (air resistance) opposes the downward pull of gravity.
  • Key Point: The faster the skydiver falls, the greater the resistance from the air.
• Skydiver QER(3-4)

  
  

  3. Terminal Velocity:

  • Forces acting: The skydiver reaches terminal velocity when the force of air resistance equals the force of gravity.
  • Effect on motion: At this point, the skydiver no longer accelerates and falls at a constant speed (terminal velocity).
  • Key Point: Terminal velocity depends on the skydiver's body position, mass, and the drag coefficient of their body shape.

  4. Parachute Deployment:

  • Forces acting: When the parachute is deployed, it dramatically increases the surface area, causing a sharp increase in air resistance.
  • Effect on motion: The sudden increase in resistance causes the skydiver's speed to rapidly decrease.
  • Key Point: The parachute slows the fall by increasing air resistance, reducing the velocity to a safe level.
• Skydiver QER (5-6)

  5. Deceleration (After Parachute Opens):

  • Forces acting: The upward force of air resistance becomes much greater than the downward force of gravity as the parachute slows the descent.
  • Effect on motion: The skydiver's velocity decreases significantly until it reaches a much slower constant speed, known as the "parachute descent speed."
  • Key Point: The skydiver's speed is now low enough to ensure a safe landing.

  6. Final Landing:

  • Forces acting: As the skydiver nears the ground, the force of gravity is still pulling downwards, but the air resistance from the deployed parachute ensures a safe, slow descent.
  • Effect on motion: The skydiver gently lands, with the parachute providing a controlled and gradual deceleration to avoid injury.
  • Key Point: The parachute ensures the velocity is slow enough for a safe landing, preventing injury from impact.