14 Actionable Difference between Cellular Respiration and Photosynthesis

What is the difference between Cellular Respiration and Photosynthesis?

Respiration and photosynthesis are chemical reactions that tend to complement each other in the environment. These two scientific terms are quite crucial when it comes to the existence of a living organism.

The article provides a detailed insight into the difference between cellular respiration and photosynthesis to help prevent confusion among learners. Take the time to read through it.

Difference between Cellular Respiration and Photosynthesis

What Is Cellular Respiration?

Cellular respiration is the process whereby glucose is broken down in the presence of oxygen to release carbon dioxide, water, and energy.

The process normally takes place in mitochondria and it tends to occur in the absence of sunlight. The energy produced helps to facilitate metabolic activities and other cellular work.

Here is the chemical equation for cellular respiration:

Glucose + Oxygen                                     Carbon dioxide + water + Energy

The process of respiration undergoes several stages to be complete such as Glycolysis, Transition Reaction, Krebs cycle, and Electron Transport Chain.

Cellular respiration can either be aerobic respiration or anaerobic respiration. Take the time to note the difference between aerobic and anaerobic respiration.

What Is Photosynthesis?

Photosynthesis is the process where green plants convert sunlight and water into glucose or food. According to research, photosynthesis is an oxidation-reduction process.

Photosynthesis occurs in the chloroplast that contains the green pigment. The green chemical is the one responsible for absorbing sunlight for splitting water molecules into oxygen and hydrogen.

The oxygen separated from water is released into the atmosphere while carbon dioxide and water help to manufacture food.

Here is the word equation of photosynthesis in plants:

Carbon dioxide + water+ sunlight                                 Glucose + Oxygen

The process of photosynthesis undergoes two stages such as light stage and dark stage. Light stage occurs during the day while the dark stage occurs at night.

Comparison Chart: Cellular Respiration vs Photosynthesis 

Basic Terms Cellular RespirationPhotosynthesis
MeaningThe process where glucose is broken down to release energy responsible for various metabolic activities.The process where green plants use sunlight and water to manufacture food.
Organelles ResponsibleMitochondriaChloroplast
SunlightNot a requirementCrucial requirement
ReactantsGlucose and oxygenCarbon dioxide and water
Energy ProductionATP energy presenceYes
Chemical equation6O2 + C6H12O6 –> 6CO2 +6H2O + ATP (energy)6CO2 + 12H2O + light –> C6H12O6 + 6O2 + 6H20
StagesGlycolysis, Pyruvate Oxidation, Krebs cycle, Electron Transport ChainLight stage and dark stage
Final ProductsCarbon dioxide, ATP and waterGlucose and Oxygen
Final Electron Receptor         O2NADP+
Electron sourceGlucose, NADH +, FADH2Oxidation H2O at PSII
CatalystNo catalystChlorophyll
The fate of Carbon dioxide and OxygenOxygen is absorbed and carbon dioxide is released.Carbon dioxide is absorbed and oxygen is released.
Oxidative phosphorylationTend to occurDo not occur at all
EnergyPotential energy is converted into kinetic energyLight energy converted into potential energy

Core Difference between Cellular Respiration and Photosynthesis

  1. Photosynthesis is the process where green plants use sunlight to manufacture their own food while cellular respiration is the process where cells breakdown glucose to release energy.
  2. Cellular respiration takes place in mitochondria while photosynthesis in the chloroplast of green plants.
  3. Photosynthesis occurs in two stages such as light stage and dark stage while cell respiration occurs in four stages as  Glycolysis, Pyruvate Oxidation, Krebs cycle, and Electron Transport Chain.
  4. Carbon dioxide, Water, and Light energy are the main inputs of photosynthesis while cell respiration is Glucose and Oxygen.
  5. The metabolic process during photosynthesis is Anabolic while cell respiration is Catabolic.
  6. Glucose and Oxygen are the main output of photosynthesis while Carbon dioxide and Water are the main output of cell respiration.
  7. The potential energy in cell respiration is converted into kinetic energy while light energy in photosynthesis is converted into potential energy.

Similarities of Cellular Respiration and Photosynthesis

  1. Both occur in cell organelles
  2. Both result in energy production
  3. Both have electron carriers
  4. Both processes are Reduction-Oxidation Reaction
  5. Both need mitochondria 
  6. Both use oxygen 
  7. Both processes use ATP molecules 
  8. Both occur in green plants 
  9. Both produce carbon dioxide at the end
  10. Both processes are catabolic processes 

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Comparison Video


These biological processes in the living organism are quite crucial. They play a big role in the regulation of carbon dioxide and oxygen in the environment.

Understanding the core difference between cellular respiration and photosynthesis helps to clear out the confusion experienced by students about these terms.

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