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Difference Between Photosynthesis And Respiration

October 5, 2022
written by Sidra Batool

Respiration and photosynthesis are two biological processes that rely on each other to occur. They are similar in many ways but differ in their purpose.

The main difference between photosynthesis and respiration is that respiration is the process of breaking down glucose and oxygen to create water and carbon dioxide while photosynthesis does the opposite, it takes in carbon dioxide and water to create oxygen and glucose.

Even though these processes are happening simultaneously, one is considered anabolic while the other is catabolic.

image showing the Difference Between Photosynthesis and Respiration

What is Photosynthesis?

Photosynthesis is the process where plants use sunlight to convert water and carbon dioxide into glucose and oxygen. Photosynthesis is the primary way that plants obtain their food and energy.

In order to perform photosynthesis, plants need three things: Carbon Dioxide (CO2), Water, and Light Energy.

What is Respiration?

Respiration is the process of taking in oxygen and releasing carbon dioxide. In the case of cannabis, we are talking about the process of taking in CO2 and releasing O2.

Respiration is a necessary function for any organism to survive. When you breathe out, you are exhaling carbon dioxide (CO2) and inhaling oxygen (O2). Plants use the same processes to take in water and release nutrients.

Difference Between Photosynthesis and Respiration

Here are the key differences between Photosynthesis and Respiration:

Photosynthesis Respiration
Photosynthesis occurs only in green plants and algae. It also occurs in some bacteria like cyanobacteria.Respiration occurs in all living organisms.
It happens in a type of plastid named chloroplast.The process of respiration happens in mitochondria.
The process of photosynthesis needs light to be continued. It cannot occur in absence of light.It can occur in absence of sunlight as it is happening all the time.
Energy is required to carry out the process, so it is known as an endothermic reaction.It releases energy, so it is an exothermic reaction.
It is the process of synthesis of food in plants.It is the process of the breakdown of food articles.
It produces Glucose, oxygen, and water as a by-product.It produces Carbon dioxide, water, and ATP as a product.
Its reactants are the products of photosynthesis that are Carbon dioxide, water, and light energy.Glucose and oxygen are used as reactants in cellular respiration.