How is carbon dioxide produced by respiration, and what happens to it after it is released by organisms?

Sourav PanNovember 8, 2024

Answered

Carbon dioxide (CO₂) is produced by organisms during the process of respiration, a vital metabolic pathway that converts organic compounds into energy. Here’s how CO₂ is generated and what happens to it after its release.

Production of Carbon Dioxide through Respiration

1. Cellular Respiration

Respiration can be classified into two main types: aerobic and anaerobic.

• Aerobic Respiration:
  • This process occurs in the presence of oxygen and involves the complete oxidation of glucose. The overall chemical reaction can be summarized as:
  C6H12O6+6O2→6CO2+6H2O+energy
  • During aerobic respiration, glucose (C₆H₁₂O₆) is broken down in a series of biochemical reactions, including glycolysis, the Krebs cycle, and the electron transport chain, resulting in the production of CO₂ as a waste product.
• Anaerobic Respiration:
  • This occurs in environments lacking oxygen and results in the partial breakdown of glucose. The products vary depending on the organism; for example, yeast produces ethanol and CO₂, while some bacteria produce lactic acid. The general reaction for anaerobic respiration in yeast is:
  C6H12O6→2C2H5OH+2CO2+energy
  • Here, CO₂ is also generated as a byproduct.

2. Decomposition

When organisms die, decomposers such as bacteria and fungi break down organic matter through respiration, releasing CO₂ back into the atmosphere or water during this process.

Fate of Released Carbon Dioxide

Once CO₂ is produced and released into the environment, several pathways can occur:

1. Atmospheric Release:
   • In terrestrial ecosystems, CO₂ diffuses into the atmosphere. It contributes to the greenhouse effect and plays a role in climate regulation. Plants can absorb some of this CO₂ during photosynthesis, creating a cyclical relationship between respiration and photosynthesis.
2. Dissolution in Water:
   • In aquatic environments, CO₂ can dissolve in water, forming carbonic acid (H₂CO₃). This process affects water chemistry and can influence aquatic life. Some of this dissolved CO₂ can be utilized by aquatic autotrophs (like algae) for photosynthesis .
3. Carbon Cycling:
   • The released CO₂ becomes part of the global carbon cycle. It may be absorbed by plants or phytoplankton during photosynthesis, converted into organic matter, and eventually returned to the atmosphere through respiration or decomposition when organisms die.
4. Long-term Storage:
   • Some carbon may be sequestered in sediments or soils over longer periods, contributing to carbon storage mechanisms that mitigate atmospheric CO₂ levels