Aerobic respiration

• we need energy for living processes: ( mrsgren )

  • Movement
  • Respiration
  • Sensitivity
  • Growth
  • Reproduction
  • Excretion
  • Nutrition
• to transfer energy stored in our food, our bodies need aerobic respiration
• aerobic respiration happens in the organelle called mitochondria in cells. muscle cells contain large amount of mitochondria.
• glucose + oxygen $\rightarrow$ carbon dioxide + water (+ energy )
• $C_6H_{12}O_6\ +$$6CO_2\ \rightarrow\ 6CO_2\ +$$\ 6H_2O$
• HOW DOES GLUCOSE GET INTO CELLS FROM THE FOOD WE EAT?

  1. carbs found in food are broken down during digestion. Digestion releases the glucose
  2. Glucose is absorbed through the walls of the small intestine into the bloodstream
  3. Glucose dissolves into blood plasma and will diffuse into cells that need it for respiration
• glucose is carried by plasma
• Oxygen is carried by red blood cells
• HOW DOES OXYGEN GET INTO CELLS?

  1. When we breathe in, air fills alveoli in lungs
  2. Oxygen diffuses into bloodstream
  3. oxygen joins to the haemoglobin in cells and gets carried around in the blood vessels
  4. When it reaches a cell needing oxygen, the oxygen will diffuse into the cell
• ADAPTATIONS OF RED BLOOD CELLS:

  • no nucleus so they have a larger surface area to have more space for haemoglobin
  • Biconcave shape for large surface area to carry more oxygen
  • Flexible to allow them to pass through narrow capillaries
  • this cell membrane for faster diffusion of oxygen
• ADAPTATIONS OF ALVEOLI TO EXCHANGE O2 AND CO2:

  • walls are thin for easy diffusion
  • surrounded by blood vessels called capillaries for good blood supply and shorter distance for diffusion
  • bouncy/ folded shape - large surface area for more surfaces for diffusion of oxygen and carbon dioxide
  • Moist - gases easily dissolve and then diffuse across
• HOW DOES CO2 LEAVE THE BODY?

  • co2 diffuses out of cells and into blood plasma
  • Then the blood transports the co2 to the lungs, when it diffuses into alveoli, and its exhaled
• Respiration is an exothermic reaction, meaning it releases thermal energy.