Difference Between Combustion And Respiration

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What Is Combustion/Burning?

Combustion is the scientific word for burning. In a combustion reaction, a substance reacts with oxygen from the air and transfers energy to the surrounding. Combustion releases a large amount of energy in a single step and most of it changes into heat and some at times into light, raising the temperature greatly.  

 Types of Combustion

There are two major types of combustion, which include:

  • Complete combustion. In complete combustion, the reactant burns completely in oxygen producing water and carbon dioxide as byproducts. A good example of this reaction is when a candle burns.
  • Incomplete Combustion. Incomplete combustion will occur when there is limited oxygen to allow the fuel to react completely to produce carbon dioxide and other products such as soot and carbon monoxide. Complete combustion also happens when the combustion is quenched by a heat sink, such as a solid surface or flame trap.

Examples Of Combustion

  • Burning of wood or coal to heat your home
  • Burning of petrol or diesel to run your car
  • Combustion of natural gas or LPG to cook on your cooker
  • Fireworks
  • Production of energy in thermal power plants

What You Need To Know About Combustion/Burning

  • Combustion refers to a physio-chemical reaction which occurs between a fuel and an oxidizing agent producing energy in the form of heat and light.
  • In combustion, the substance is burned when there is presence of oxygen where the end product is light and heat.
  • Combustion is a non-cellular process.
  • Combustion requires external heating to burn the sugar molecules.
  • Combustion is not controlled by enzymes.
  • The energy is released in the form of heat and light during combustion.
  • Combustion occurs only in aerobic conditions.
  • Combustion does not help in ATP formation.
  • Combustion is a fast process.
  • No intermediates are produced in combustion.
  • Combustion involves only one step.
  • Combustion is a physio-chemical reaction.
  • Combustion has to be initiated by applying heat.
  • Combustion produces flames.
  • The substrate is directly oxidized in combustion.
  • During combustion, the temperature rises.
  • Combustion is not a continuous process.
  • Carbon dioxide, sulfur dioxide, nitric oxide, oxygen etc are the byproducts of combustion.

What Is Respiration?

Respiration is a chemical reaction that happens in all living cells including animal and plant cells. It is the way that energy is released from glucose so that all the other chemical processes needed for life can happen. In this process glucose is broken down in the presence of oxygen to producing carbon dioxide and water and ultimately producing energy in the form of ATP for the cells of the body.

Respiration can be categorized into two broad classes, that is, physiologic respiration and cellular respiration. Although physiologic respiration is necessary to sustain cellular respiration and thus life in animal, the two processes are different from each other. Cellular respiration takes place in individual cells of the organism while physiologic respiration involves diffusion and transport of metabolites between the organism and the external environment.

What You Need To Know About Respiration

  • Respiration refers to the biochemical process in which cells of an organism obtain energy by combining oxygen and glucose, releasing carbon dioxide, water and ATP.
  • In respiration, the cells and tissues are supplied with oxygen which is needed for metabolic activities of the body.
  • Respiration is a type of biochemical process that occurs inside the cell.
  • Respiration does not require external heating.
  • Respiration is controlled by enzymes. A number of enzymes are required one for each step or reaction.
  • The energy released during respiration is stored in ATP molecules, while a small amount of energy is liberated in the form of heat.
  • Respiration can occur in both aerobic and anaerobic conditions.
  • Respiration helps in the formation of ATP.
  • Respiration is a slow process.
  • A number of intermediates are formed. They are used in the synthesis of different organic compounds.
  • Respiration involves a series of steps.
  • Respiration is a biochemical reaction.
  • Respiration is a natural process.
  • Respiration does not produce flames.
  • Oxidation occurs at the end of reaction (terminal oxidation) between reduced coenzymes and oxygen.
  • During respiration temperature remains constant.
  • Respiration is a continuous process, it continues as long as the living organism is alive.
  • Carbon dioxide and water are the byproducts of respiration.

Also Read: Difference Between Cellular Respiration And Photosynthesis

Difference Between Combustion And Respiration In Tabular

BASIS OF COMPARISON COMBUSTION RESPIRATION  
Description Combustion refers to a physio-chemical reaction which occurs between a fuel and an oxidizing agent producing energy in the form of heat and light.   Respiration refers to the biochemical process in which cells of an organism obtain energy by combining oxygen and glucose, releasing carbon dioxide, water and ATP.  
Oxygen In combustion, the substance is burned when there is presence of oxygen where the end product is light and heat.   In respiration, the cells and tissues are supplied with oxygen which is needed for metabolic activities of the body.  
Occurrence Combustion is a non-cellular process.   Respiration is a type of biochemical process that occurs inside the cell.  
External Heating Combustion requires external heating to burn the sugar molecules.   Respiration does not require external heating.  
Enzymes Combustion is not controlled by enzymes.   A number of enzymes are required one for each step or reaction.  
Energy The energy is released in the form of heat and light during combustion.   The energy released during respiration is stored in ATP molecules, while a small amount of energy is liberated in the form of heat.  
Condition For Occurrence Combustion occurs only in aerobic conditions.   Respiration can occur in both aerobic and anaerobic conditions.  
ATP Formation Combustion does not help in ATP formation.   Respiration helps in the formation of ATP.  
Speed Of Occurrence Combustion is a fast process.   Respiration is a slow process.  
Intermediates No intermediates are produced in combustion.   A number of intermediates are formed.
Steps Involved Combustion involves only one step.   Respiration involves a series of steps.  
Type of Reaction Combustion is a physio-chemical reaction.   Respiration is a biochemical reaction.  
Initiation Combustion has to be initiated by applying heat.   Respiration is a natural process.  
Production Of Flames Combustion produces flames.   Respiration does not produce flames.  
Oxidation Of The Substrate The substrate is directly oxidized in combustion.   Oxidation occurs at the end of reaction (terminal oxidation) between reduced coenzymes and oxygen.  
Temperature During combustion, the temperature rises.   During respiration temperature remains constant.  
Nature of The Process Combustion is not a continuous process.   Respiration is a continuous process, it continues as long as the living organism is alive.  
Byproducts Carbon dioxide, sulfur dioxide, nitric oxide, oxygen etc are the byproducts of combustion.   Carbon dioxide and water are the byproducts of respiration.  

Similarities Between Combustion And Respiration

  • Both have oxides as by-products
  • Both processes involve the burning of a substance.
  • In both processes, the substance undergoes oxidation in the presence of oxygen.
  • Products of respiration and burning/combustion are simple chemical compounds, mostly in the gaseous phase.
  • Both processes use oxygen to oxidize chemical bonds.
  • Both processes liberate energy.
  • Both are catabolic reactions.