The oxidation of glucose to release energy or create ATP is the main difference between respiration and combustion, whereas external heat is used to burn a substance in combustion to release energy. Energy is required by living things so that their cells can operate. While some operations in cells occur without the usage of energy, this is not the case for most cellular processes. The process of producing cellular energy, primarily in the form of ATP, is known as cellular respiration. The main energy source in this process is glucose. As glucose molecules are oxidized in the presence of oxygen during respiration, ATP molecules are produced. Energy is also produced by combustion, however, it only results in heat. It needs a supply of outside heat. As a result, combustion and respiration are different from one another.

In order for living cells to make ATP, or chemical energy, glucose molecules must be broken down during respiration. Conversely, combustion refers to the act of burning something to release energy. So, the main distinction between combustion and respiration is this. Although combustion is a non-cellular activity that happens quickly and uncontrollably, respiration is a cellular function that happens slowly and under control.

Also Read: Cell

Respiration

The process by which all living things produce the energy they need to survive is called respiration. Cellular respiration is another name for this process because it takes place inside the cells. Normally, carbon dioxide and oxygen are exchanged. Utilizing oxygen, the cells release carbon dioxide. This style of breathing is known as aerobic respiration. Without oxygen, breathing is possible under some circumstances. This mechanism is known as anaerobic respiration. It is also known by the term fermentation.

The process by which nutrients are transformed into usable energy in a cell is known as cellular respiration. Energy is released step by step as the chemical bonds break down in phases during this biochemical process. Less than 50% of the energy is released as heat. It occasionally releases light. The majority of the energy is stored in ATP molecules, which prevents the temperature from rising. In the course of respiration, oxidation takes place at the end of the reaction between oxygen and coenzymes. Numerous intermediates are produced during respiration and are then employed in the production of various chemical molecules. Several enzymes are involved, and one enzyme is needed for each step or reaction.

All living things (plants, animals, and microorganisms) engage in cellular respiration, which is largely an energy-yielding dissimilation activity. In this process, complex materials with high energy content typically carbs (starch, glycogen, sucrose, glucose), proteins, or lipids are gradually broken down into simpler materials with lower energy content under the direction of enzymes. High energy phosphate (P), which is bound in ADP (adenosine diphosphate) and held in pyrophosphate bonds of ATP (Adenosine triphosphate), is released at particular specified states.

Also Read: Respiration

Combustion

In combustion, oxygen is usually released together with heat and light in the form of flame. Due to the nature of the chemical reaction and the fact that more energy is produced than can be released into the surrounding medium, the temperature of the reactants is increased, accelerating the reaction even further, and the rate at which the reactants combine is high.

Combustion is a non-cellular and uncontrolled process where energy is released all at once by burning materials. It is a physicochemical reaction in which chemical reactions take place all at once rather than sequentially. The majority of the energy is released as heat. In the process, the temperature rises dramatically and light is also produced. The production of ATP is not a part of this process. In this case, combustion immediately oxidizes the substrate without the creation of any intermediates. There are no enzymes needed for the burning process.

People have been observing and thinking about combustion, fire, and flame since the start of time. Every society has developed its own justification. Greek philosophers used philosophical ideas to explain combustion, one of which was that all combustible bodies possessed an “inflammable essence” that manifested itself when the body was burned to interact with air. Large amounts of energy are released during combustion, most of which is converted to heat and occasionally to light, which significantly raises the temperature. Each stage of the energy released during cellular respiration is accompanied by the creation of ATP. Only a small proportion of energy is converted to heat. 

 

Difference Between Respiration and Combustion

Similarities Between Respiration and Combustion

• Burning of the substrate is a necessary step in both combustion and respiration.
• Both of these procedures involve the oxidation of the material (in presence of oxygen).
• Respiration and Combustion, both of them, release oxygen. 
• Oxides of the compound, involved in the reaction, are some byproducts of respiration and combustion. 

FAQs on Respiration and Combustion

Question 1: Define Cellular Respiration.

Answer: 

Cells convert sugars into energy through a process called cellular respiration. Cells need fuel and an electron acceptor to power the chemical process that converts energy into usable forms, such as ATP and other forms of energy to power cellular reactions.

Question 2: How can combustion and respiration release energy?

Answer:

In respiration, the energy is released as heat and ATP, but in combustion, the energy is released as heat.

Question 3: How is cellular respiration linked to combustion?

Answer: 

Respiration and combustion are related to one another in some ways, including The dissolution of chemical bonds is a component of redox reactions, which include burning and biological respiration. Both cases need the use of oxygen. Although they both include burning, respiration is referred to as “slow burning” while combustion is burning.

Question 4: Using sugar as an example, describe respiration and combustion.

Answer: 

As a result of biological oxidation of sugar or glucose, molecules inside the cell uses oxygen gas, respiration results in the release of energy, or ATP (adenosine triphosphate). However, if we are talking about sugar combustion, it is just the burning of sugar that causes it to char, producing carbon dioxide and water in the process.