1. Respiration Chapter 10

3. Why do living organisms respire? Light  chemical energy ultimate source of energy (light) (stored in organic molecules) protein fat carbohydrate respiration photosynthesis  energy

4. Respiration glucose + oxygen  carbon dioxide + water + energy Definition: Respiration is the oxidation of food substances with the release of energy in living cells carbon dioxide + water  glucose + oxygen light energy chlorophyll Photosynthesis: in living cells

6. Aerobic vs Anaerobic respiration

7. Aerobic respiration ( in the presence of O 2 ) glucose + oxygen  carbon dioxide + water + energy in living cells Anaerobic respiration ( in the absence of O 2 ) Glucose  ethanol + CO 2 + energy partial breakdown Energy yield is smaller c.t. aerobic respiration

8. Alcoholic fermentation raising of bread smell Qn: Yeast is able to respire aerobically and anaerobically. How do we make them respire anaerobically? Glucose  ethanol + CO 2 + energy yeast

9. Olympics (400m relays) 1) aerobically 2) anaerobically

10. Anaerobic respiration in muscles Start End respire aerobically panting (remove CO 2 ; take in O 2 ) respire anaerobically (to meet energy demands; for short periods) (O 2 abundant) (less O 2 ) (less O 2 ) (less O 2 ) (shortage of O 2 ) Energy output max. Heavy breathing Extra energy produced (O 2 debt)

11. Changes in muscles during vigorous contractions

12. Anaerobic respiration in muscles glucose  lactic acid + energy Insufficient O 2 (vigorous muscle contraction) accumulation fatigue (high conc. of lactic acid) Muscle are said to incur an O 2 debt

14. During rest… Muscles (lactic acid) Liver lactic acid -> energy oxidised lactic acid transported to Glucose lactic acid -> glucose ready to go glucose transported to

16. How do we know if organisms respire?

17. 10.1 To show respiration in an animal Live cockroach Dead cockroach (soaked in formalin to prevent decay) Leave for a few hours

18. To show respiration in an animal Live cockroach Dead cockroach (soaked in formalin to prevent decay) After a few hours Note time taken for candle flame to go off

19. 10.2 To find out whether CO 2 is given off during respiration Hydrogen carbonate indicator Predict the likely observations from the experiment (red) (yellow) CO 2 present CO 2 absent

20. 10.2 To find out whether CO 2 is given off during respiration ( absorbs CO 2 ) ( chalky; presence of CO 2 ) ( ensures CO 2 absent )

21. 10.3 To find out whether carbon dioxide is given off during fermentation ( creates anaerobic environment ) ( turns chalky; presence of CO 2 ) (bubbles of CO 2 evolving)

22. 10.4 To find out whether heat is produced during respiration ( preservative + kills bacteria ) ( preservative + kills bacteria )