1. Respiration…the burn of life
Horticulture

2. Objectives Define respiration Explain the process of respiration
Compare respiration to combustion
Explain why plants respire
Why should we care about respiration?

3. Define Respiration
It is the controlled expenditure of an organism's energy reserves to sustain its life processes
Occurs 24/7
All cells of the plant respire, not just those containing chlorophyll

4. Respiration Occurs in the mitochondria
Exact opposite process of photosynthesis
Consumes oxygen and gives off carbon dioxide

5. Formula Uses stored energy (E) and gives off heat
Opposite of photosynthesis
C6H12O + H2O + 02 = CO2 + H2O + E

6. Where, what? Occurs in mitochondria in both plant and animal cells
Largest organelle in the cell
“Powerhouses” of the cell
Provide storage areas fro respiration
Cell may have 2,500 mitochondria

7. Combustion and Respiration
Burn a carbohydrate and get carbon dioxide, water, and heat
C6H12O6 + heat = CO2 + H20 + heat
Respiration is the exact same!!!

8. Differences Combustion releases ALL the energy at 1 time.
Respiration is a controlled release, plants can use the E as it is released.
E is released in the form of ATP

9. WHY do plants respire? Cell respiration E is defined as:
The process breaks chemical bonds and produces heat that is used by the cells of the plant for work.
E is defined as:
The ability to do work

10. Biological Work Maintenance of life and life processes: Growth
Development
Repair
Movement
Reproduction
Transportation

11. How it works…
Respiration converts the E stored in the nutrients (carbs, proteins, starches) into ATP which is useable by the cell.

12. Factors affecting respiration:
Temperature:
As temperature increases, so does the rate of respiration.
At normal temperatures, respiration increases two to four times for each 18 F rise in temperature.
Oxygen:
abnormally low concentrations of oxygen in an environment will result in a lower rate of respiration.

13. Factors affecting respiration:
Soil conditions:
Compacted or waterlogged soils exclude air (oxygen).
Respiration in a plant's root system is inhibited under such conditions.
Light:
Plants grown in low light photosynthesize at a reduced rate.
Therefore, the level of available carbohydrates (glucose and others) and rate of respiration are also reduced.

14. Growth rate and metabolic activity:
Maintenance respiration provides energy for maintenance of existing cells and tissues.
Growth respiration provides energy for production of new cells and tissues. age and the availability of glucose affect the rate of respiration

15. Respiration and Agriculture
Better Crop Management
Better post-harvest handling of crops
Respiration=24/7, plants need to be able to photosynthesize enough to provide E for respiration during day and night.
If not, no E for growth

16. Respiration and Ag
Plants grow best with night temps 9degrees cooler than daytime.
If temps are too high, respiration increases and growth is stalled
Temps too cool, respiration will be too low and growth processes won’t occur

17. Respiration and Ag
Closely tied with degradation (breakdown of tissues) in harvested crops
By slowing resp. rates after harvest, growers can improve quality

18. Respiration and Ag Refrigeration or cooling helps slow respiration
Can increase N, forces out O2, decrease respiration
Think of bananas and flowers

19. Fermentation Anaerobic respiration (no oxygen)
Glucose is converted during several steps into alcohol (ethanol)
Important for making silage