Aerobic Respiration - Defination, Diagrams,Differences

What is Aerobic Respiration?

Cellular respiration can be classified into aerobic and anaerobic forms. Aerobic respiration is also known as aerobic metabolism or oxidative metabolism. It is a chemical process where oxygen is utilised to form energy from carbohydrates. Some basic points about aerobic respiration are discussed below:

• Aerobic respiration is performed in the presence of oxygen where organisms use oxygen to convert fats and sugar to convert it into chemical energy.

• Aerobic respiration generally produces high amounts of energy which is typically between 36-38 ATP.

• The byproducts of aerobic respiration are carbon dioxide (CO₂) and water (H₂O)

• There is long-term sustenance of energy which keeps us energy for long periods.

Chemical Equation of Aerobic Respiration

Glucose (C₆H₁₂O₆) + Oxygen 6(O₂) → Carbon-dioxide 6(CO₂) + Water 6 (H₂O) + Energy (ATP)

• Energy is extracted by breaking down glucose molecules using oxygen during aerobic respiration.

• This results in the formation of energy, water and carbon dioxide as end products.

• The energy released is 2900kJ and further this is used to generate energy in the form of ATP.

• This oxygen is entered into the stomata of plant cells and reaches the epidermis cell present in the leaf and stem. This is done during the respiration process.

• During photosynthesis, the energy is released in the form of food.

Steps of Aerobic Respiration

Four steps are occurring in the respiration process:

Glycolysis

• Glycolysis occurs in the cytosol where glucose is broken down into two molecules of ATP and two molecules of NADH.

Formation of Acetyl Co-A

• Pyruvate is oxidized in mitochondria.

• This forms a 2-carbon Acetyl group. This is further combined with coenzyme A.

Krebs Cycle

• In Krebs cycle, oxaloacetate binds to acetyl coenzyme A and citric acid is produced.

• Two molecules of CO₂ and one ATP are formed.

• The reduced form of NADH and FADH is formed.

• Involves multiple reactions which produce CO₂ and one ATP.

Electron Transport Chain

• A large amount of energy is released in the form of ATP.

• ETC takes place due to the transfer of electrons from NADH and FADH.

• It results in 34 ATP Molecules from one glucose molecule.

Functions of Aerobic Respiration

The functions of aerobic respiration can be discussed as follows:

• Energy production for all processes in cells.

• ATP production leads to other important functions like growth, repair, and maintenance.

• ATP provides energy for the sodium-potassium pump, which helps in movement, thinking, and coordinating with the outer world, for example.

• ATP also provides energy for proteins and enzymes to function.

Aerobic Respiration and Weight Loss

The aerobic respiration process is connected to weight loss due to the high metabolic rate that comes with it. Due to this, high calories are burnt during workouts and energy is restored from the fats stored in the body. Some important mechanisms are discussed below in the points.

• The carbon atoms released as carbon dioxide come from the food we eat, which is sugar or fat.

• We tend to breathe heavily while exercising and engaging in calorie burning activities. This is when the body burns out more oxygen and sugar at a faster rate than normal, and there is more production of ATP for energy generation. More carbon dioxide is emitted.

• When the body uses ATP at a faster rate than normal, to compensate for the need for more oxygen molecules for the cells, the cells start performing anaerobic respiration to supply oxygen at a fast rate.

• As a result, this process burns more sugar and fat in the body, causing the body to lose weight.

Differences Between Aerobic And Anaerobic Respiration

Differences between aerobic and anaerobic respiration are given below:

Exam Relevance

During the preparation of the exam, there are different types of questions asked about Aerobic Respiration in different forms. The table given below contains the different patterns of questions asked in different exams.

Tips & Tricks to Remember

It's hard to remember everything in a single go. We made the entire problem easy. Some of the tricks regarding Aerobic Respiration are given below which you can use to memorize the important points.

"GKEE: Glycolysis, Krebs, Electron Transport"

• G: Glycolysis

• K: Krebs Cycle

• E: Electron Transport Chain

ATP Yield: "2-2-34"

• 2: ATP produced in Glycolysis

• 2: ATP produced in the Krebs Cycle

• 34: ATP produced in the Electron Transport Chain

• Total: 36-38 ATP per glucose molecule

Key Coenzymes: "NADH-FADH₂"

• NADH: Carries electrons from Glycolysis and Krebs Cycle to the Electron Transport Chain

• FADH₂: Also carries electrons, but produces slightly less ATP compared to NADH

Importance of Oxygen: "O₂: Oxidation and ATP"

• O₂: Essential for the final electron acceptor in the Electron Transport Chain

• Oxidation: Facilitates the production of ATP through oxidative phosphorylation

Differences from Anaerobic Respiration: "O-D-Y"

• O: Oxygen required for aerobic respiration, absent in anaerobic

• D: Different end products (CO₂ and H₂O in aerobic, lactic acid or ethanol in anaerobic)

• Y: Yield of ATP is significantly higher in aerobic respiration (36-38 ATP) compared to anaerobic (2 ATP)

Aerobic Respiration NEET MCQs

Q1. Identify the step in the tricarboxylic acid cycle that does not involve oxidation of the substrate.

1. Malic acid → Oxaloacetic acid

2. Succinic acid → Malic acid

3. Succinyl-CoA → Succinic acid

4. Isocitrate → alpha-ketoglutaric acid

Correct answer: 3) Succinyl-CoA → Succinic acid

Explanation:

Oxidation does imply the loss of electrons, often in the form of hydrogen, from a molecule, thereby increasing its oxidation state. Often this process is associated with the transfer of electrons to an electron acceptor, which is reduced.
The most fundamental oxidation-independent key reaction of the TCA cycle is the transmutation of succinyl CoA to succinate. Succinyl-CoA synthetase catalyzes the step, where it results in the release of CoA and forms succinate while generating GTP or ATP by substrate-level phosphorylation.
Hence, though most reactions in the TCA cycle are oxidation reactions, this reaction of succinyl CoA being reduced to succinate is the exception, in which the acceptor molecule does not get oxidized but instead takes part in substrate-level phosphorylation for the release of energy.

Hence, the correct answer is Option 3) Succinyl-CoA → Succinic acid

Q2. The ultimate electron acceptor of respiration in an aerobic organism is

1. Cytochrome

2. Oxygen

3. Hydrogen

4. Glucose

Correct answer: 2) Oxygen

Explanation:

Oxygen is the final electron acceptor in the electron transport chain during aerobic respiration.
This process involves the transmission of electrons via a sequence of protein complexes in the mitochondrial membrane, which eventually combine with protons and oxygen to produce water (H2O).
Because of its high electronegativity, oxygen is very good at taking up electrons, which promotes oxidative phosphorylation, which produces ATP.
The electron transport chain would stop working in the absence of oxygen, forcing aerobic organisms to rely on less effective energy-producing mechanisms like fermentation or anaerobic respiration.

Hence, the correct answer is option 2) Oxygen.

Q3. The breaking of the C-C bonds of complex compounds through oxidation within the cells, leading to the release of a considerable amount of energy is called

1. Photosynthesis

2. Glycolysis

3. Cellular respiration

4. Breathing

Correct answer: 3) Cellular respiration

Explanation:

The breaking of the C-C bonds of complex compounds through oxidation within the cells, leading to the release of a considerable amount of energy is called respiration. Respiration occurs in multiple steps including glycolysis, the Krebs cycle, and the electron transport chain, and can be classified as aerobic or anaerobic.

Hence, the correct answer is option 3) Cellular respiration.

Also Read:

• MCQs on Cellular Respiration

• Link reaction between Glycolysis and Krebs Cycle

• Hexose Monophosphate Shunt Pathway

FAQs on Aerobic Respiration

What do you mean by aerobic respiration?

Aerobic respiration is the process by which cells break down glucose completely in the presence of oxygen to release energy. It occurs mainly in the mitochondria and involves oxidative breakdown of glucose into carbon dioxide and water. This process is highly efficient and produces a large amount of ATP, which is the main energy currency of the cell. Aerobic respiration is the most common form of respiration in plants, animals, and many microorganisms.

What are the steps of aerobic respiration?

Aerobic respiration occurs in several sequential steps:

1. Glycolysis: breakdown of glucose into pyruvate in the cytoplasm, producing 2 ATP and 2 NADH.

2. Pyruvate oxidation: conversion of pyruvate into acetyl-CoA, releasing CO₂ and producing NADH.

3. Krebs cycle: occurs in the mitochondrial matrix, producing ATP, NADH, FADH₂, and releasing CO₂.

4. Electron Transport Chain (ETC) and Oxidative Phosphorylation: occurs in the inner mitochondrial membrane, using oxygen as the final electron acceptor and generating the majority of ATP.
   
   

How many ATP are produced in aerobic respiration?

In aerobic respiration, complete oxidation of one molecule of glucose yields about 36 to 38 ATP molecules. This includes 2 ATP from glycolysis, 2 ATP from the Krebs cycle, and about 32–34 ATP from the electron transport chain and oxidative phosphorylation. The exact number can vary slightly between prokaryotic and eukaryotic cells, but aerobic respiration always produces far more ATP than anaerobic respiration.

What is the difference between aerobic and anaerobic respiration?

The main difference is that aerobic respiration requires oxygen, while anaerobic respiration occurs without oxygen. In aerobic respiration, glucose is completely oxidized to carbon dioxide and water, releasing 36–38 ATP per glucose molecule. In anaerobic respiration, glucose is only partially broken down, producing much less energy (only 2 ATP) along with by-products like lactic acid in animals or ethanol and CO₂ in yeast. Thus, aerobic respiration is more efficient, while anaerobic is useful during oxygen deficiency.

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