Respiration and it's different types pptx

Respiration and it's different types.which provide us ATP

1. Respiration Biological process whereby the energy stored in carbohydrates from PS is released in a step-wise, controlled manner. Energy released is coupled to the synthesis of ATP. ATP is essential for plant cell maintenance, growth and development

2. Carbohydrate Conversion Starch glucose Sucrose + water glucose + fructose

3. Equation for Aerobic Respiration C 6 H 12 O 6 + 6O 2 + 6H 2 O 6CO 2 + 12H 2 O + energy (glucose) (ATP) 1 mole glucose 36 ATP

4. Efficiency of Aerobic Respiration ADP-P bond releases -7.6 kcal/mol ATP when bond is broken Theoretical energy yield from burning 1mol glucose in a calorimeter = -686 kcal/mol Practical yield from burning 1mol of glucose in the cell with oxygen = 36ATP 36 ATP X -7.6 kcal/mol = -274 kcal/mol glucose 274/686 kcal/mol X 100 = 40% efficiency

5. Efficiency of Anaerobic Respiration ADP-P bond releases -7.6 kcal/mol ATP when bond is broken Theoretical energy yield from burning 1mol glucose in a calorimeter = -686 kcal/mol Practical yield from burning 1mol of glucose in the cell without oxygen = 2 ATP 2 ATP X -7.6 kcal/mol = -15.2 kcal/mol glucose 15.2/686 kcal/mol X 100 = 2.2% efficiency

6. 3 Stages of Respiration Glycolysis TCA Cycle Electron Transport Chain

7. Glycolysis Occurs in all living organisms Only stage which can occur without oxygen Oldest stage of respiration operated for billions of years in anaerobic organisms Converts glucose to 2 pyruvates in cytosol with O 2 goes on to TCA cycle without O 2 pyruvate is converted to lactate or ethanol (fermentation) Yields 2ATP/mole glucose in the absence of O 2

8. Glycolysis Glucose (6C) 2 Pyruvate (3C) Ethanol Lactate TCA Cycle CO 2 +O 2 -O 2 -O 2

9. TCA cycle

10. Electron Transport System NADH and FADH 2 e - e - 4e - + 4H + + O 2 2H 2 O cyt. oxidase H + H + ATP

11. Chemiosmotic model H + H + H + H + H + H + H + H + H + H + H + H + H + H + H + Ion concentration difference represents a source of free energy

12. Chemiosmotic model H + H + H + H + H + H + H + H + H + H + H + H + H + H + H + The energy represented by the H + gradient is converted to a chemical form (ATP) via the ATP synthase

13. 3 Stages of Respiration Glycolysis cytoplasm with or without oxygen present breaks glucose (6C) into 2 pyruvates (3C) TCA Cycle mitochondrial matrix only if oxygen present converts pyruvate via acetyl CoA into CO 2 ; generates NADH and FADH 2 Electron Transport Chain mitochondrial membranes = cristae transfers electrons from NADH and FADH 2 to reduce O 2 to H 2 O and generate ATP

14. Mitochondria Spherical to oval about 1 micron diameter # mito./cell increases with demand for respiration; 300-1000/root tip cell Double-membrane bound outer smooth inner folds forming cristae controls movement in/out site of electron transportm Matrix soluble phase site of TCA cycle; DNA, RNA, ribosomes matrix cristae

15. Alternate Fates of Glucose C Not all C respired to CO 2 Intermediates of respiration branch off: amino acids pentoses for cell wall structure nucleotides porphyrin biosynthesis fatty acid synthesis lignin precursors precursors for carotenoid synthesis, hormones

16. Factors Affecting Resp. Rate [Substrate] [ATP] [Oxygen] Temperature Plant type Plant organ Plant age

17. Factors: Substrate Availability Resp. higher right after sundown compared to right before sunrise due to [S] Shaded leaves respire slower than lighted leaves Starvation of plant tissue results in utilization of proteins High [ATP] in cell and get negative feedback on resp.

18. Factors: [Oxygen] No effect until [O 2 ] < 1% Cyt oxidase not sensitive to O 2 until 0.05% O 2 diffuses in water 10,000 X slower than in air Some plants have intercellular air system, e.g., aerenchyma in shoots and roots (rice) Very low levels of O 2 see accelerated breakdown of sugars to ethanol and CO 2 evolved = Pasteur Effect

19. Factors: Temperature Q 10 for respiration is 2.0 - 2.5 between 5 and 25C Q 10 = rate of process at one temperature divided by the rate at 10C lower temp. Decreases with most plant tissues at 30-35C O 2 being used so fast, it can’t diffuse fast enough into tissues Tropical regions - 70-80% PS C lost to resp. due to high night temperatures and resp. rates

20. Factors: Plant Type/Organ/Age Resp. rate tends to increase with age of plant Young trees lose about 1/3 daily PS C to resp. and doubles with older trees as ratio of PS/Non-PS tissue decreases Greater metabolic activity = greater resp. rates Root tips, dev. buds and meristematic regions in general have higher respiration rates In veg. tissues, resp. decreases from the tip to the mature regions Seeds - low resp. rates, dormant, desiccation results in slowdown of respiration

21. Factors: Plant Type/Organ/Age (cont.) Ripening Fruit Resp. high when young cells are dividing and growing Climacteric Fruit (apples, tomatoes) Sharp increase in rate immediately before fruit ripening = climacteric rise in respiration Coincides with full ripeness and flavor and preceded by huge increase in ethylene production This leads to senescence and decrease in respiration Non-climacteric Fruit Citrus, cherries, grapes, pineapple, strawberries Insensitive to ethylene

22. Controlled Atmosphere Storage Lower O 2 (2% - 3%) & raise CO 2 (5% - 10%) slows down resp. No ethylene high CO 2 also inhibits ethylene synthesis Temps. typically about -1 to -0.5C Pick apples in Sept./Oct. when green and immature and store in CA expose to normal air with ethylene when ready to sell fresh apples in March

23. Cyanide Resistant Respiration Aerobic resp. (cyt oxidase) in plants and animals inhibited by CN - and N 3 - (azide) bind to Fe in enzyme and halts e - transport Animals: CN causes resp. to decrease fast, virtually irreversible and fatal Plants: display a 10-25% CN-resistant resp. and alternate pathway for electron flow electron flow branches off to alternate oxidase less ATP produced

24. Cyanide Resistant Respiration (cont.) Metabolic Role? No clear role Operates when cyt oxidase poisoned Energy overflow hypothesis overflow for electrons when resp. rate exceeds demand for ATP; high with high carbo. levels Skunk cabbage, Voodoo lily, Stinking lily: CN-res. pathway causes temp. of spadix to increase 10-20C. volatilization of odiferous cmpds which attract pollinators