Factors affecting Aerobic and Anaerobic Respiration | Agriculture Optional Notes for UPSC PDF Download

External factors or Environmental Factors

Temperature

• Temperature is a critical factor that impacts the rate of respiration.
• Typically, respiration rate increases within a certain temperature range, from 5.0°C to 30.0°C.
• According to Vont Hoff's rule, a temperature rise of 10°C results in the doubling of the respiration rate.
• However, beyond 35.0°C, higher temperatures lead to a decline in the rate of respiration as enzymes begin to denature.
• Conversely, very low temperatures can render enzymes inactive, causing a decrease in the respiration rate. Cold storage of fruits and vegetables exploits this effect to prevent spoilage.

Oxygen

• Oxygen is essential for aerobic respiration since it serves as the terminal electron acceptor.
• When oxygen concentration is low, both aerobic and anaerobic respiration may occur.
• In the absence of oxygen (zero oxygen concentration), only anaerobic respiration can take place. This condition results in an infinite respiratory quotient (R.Q.).

Water

• Water plays a vital role as a medium for various metabolic activities.
• Protoplasm contains a significant percentage of water, up to 90-95%.
• Water is crucial for enzyme activation, gaseous diffusion, and transportation, among other functions.
• Dry seeds and fruits have very low respiration rates due to water scarcity, allowing for extended storage. In the presence of water, stored carbohydrates convert into soluble sugars, leading to an increase in the respiration rate.

Light

• Respiration is not directly influenced by light and can occur in both its presence and absence.
• However, light indirectly affects respiration in the following ways:
• Light can raise the temperature, potentially increasing the rate of respiration.
• Photosynthesis, driven by light, results in the production of sugars that can serve as respiratory substrates.
• Light-induced stomatal opening facilitates gaseous exchange.

Carbon dioxide (CO₂)

• Elevated levels of carbon dioxide inhibit respiration and have adverse effects on seed germination and plant growth.
• Experimental evidence has shown that increased CO₂ concentration leads to stomatal closure, reducing oxygen availability and causing a decrease in the rate of respiration.

Internal factors or Plant Factors

Protoplasm

• Meristematic cells possess highly active and dense cytoplasm, resulting in a comparatively higher rate of respiration in these cells when compared to mature cells.
• The activity of protoplasm is influenced by various factors like hydration, pH, and temperature.

Respiratory substrate

• Various types of sugars, such as glucose, fructose, and maltose, present in the cell are rapidly utilized in respiration.
• In contrast, starch and fats must be converted into a soluble form before they can serve as respiratory substrates.
• This distinction is why hospitals administer glucose directly to patients, whereas the regular diet of healthy individuals includes starch and fats.

Age of Cells

• Young cells exhibit a significantly higher rate of respiration in comparison to mature and old cells.

Wound and Injured Part

• The rate of respiration experiences a substantial increase in wounded and injured areas to support the healing process.