Respiration in Plants

1. Concept:

• Respiration is the biological oxidation process driven by enzymes, occurring in all organs of a plant’s body.

2. Raw Materials and Products of Respiration:

• Raw materials: CO2 and H2O.

• Products:

• Energy:

• A portion is stored in ATP.

• The remaining portion is released as heat to maintain a favorable temperature for life processes.

• Intermediate products.

3. Role of Respiration Energy:

• The energy stored in ATP molecules is used for:

• Material transport within the plant.

• Growth and development.

• Synthesis of organic compounds.

4. Types of Respiration:

• Anaerobic respiration:

• Occurs in plant roots during flooding, soaked seeds, or oxygen deficiency.

• Consists of two stages: sugar breakdown and fermentation.

• Aerobic respiration:

• Consists of two main stages:

• Krebs cycle: occurs in the mitochondrial matrix.

• Electron transport chain: distributed in the inner mitochondrial membrane.

• Occurs vigorously in tissues and organs during germination, flowering.

• Photorespiration:

• The process of absorbing O2 and releasing CO2 in the light.

• Occurs when light intensity is high, CO2 is depleted, and O2 accumulates in C3 plants.

• Leads to the waste of photosynthetic products.

5. Impact of Temperature on Respiration:

• As temperature rises, the intensity of respiration increases.

• The temperature coefficient (Q10) of respiration is 2-3, meaning that the intensity of respiration doubles or triples when the temperature increases by 10 degrees Celsius.