Difference Between Photosynthesis & Aerobic Respiration

Photosynthesis and aerobic respiration are part of a cyclic process of biochemical reactions. Photosynthesis requires the products of aerobic respiration (carbon dioxide and water), while aerobic respiration requires the products of photosynthesis (glucose and oxygen). Together, these reactions are involved in how cells make and store energy and in how the gas exchange between oxygen and carbon dioxide occurs.

Function

Only autotrophic organisms like plants, algae and some bacteria can perform photosynthesis, while most organisms perform aerobic respiration.

Photosynthesis

Photosynthesis requires six carbon dioxide molecules and six water molecules (plus light energy) to make glucose (sugar) and six oxygen molecules.

Aerobic Respiration

Aerobic respiration requires glucose and six oxygen molecules to make six carbon dioxide and six water molecules. During this reaction, chemical energy in the form of adenosine triphosphate (ATP) is released.

Significance

ATP is the form of energy all cells require to perform the functions necessary to life. In other words, during aerobic respiration, nutrients (sugars) are converted into the form of chemical energy cells can use and store.

Considerations

Plants perform both photosynthesis and aerobic respiration. Respiration can also occur in yeast or bacteria in the absence of oxygen, which is called anaerobic respiration. Anaerobic respiration is also known as fermentation, and is the process by which beer, wine, yogurt, soy sauce and other food products are made.

References

• Respiration and Photosynthesis
• Biology: Concepts and Connections; Neil A. Campbell; 2009
• Anaerobic Respiration