Question

Define aerobic respiration with example.

Answer 1

Hint: Cellular respiration is a catabolic process that breaks the complex molecules into smaller molecules and generally releases energy. The process of respiration occurs in both conditions in the presence and absence of Oxygen.

Complete answer:
Aerobic respiration is a biological process that involves the breakdown of sugar in the presence of oxygen and releases ${ CO }_{ 2 }$, water, and a large amount of energy. In this process, oxygen acts as an electron acceptor which produces ATP more effectively. The chemical reaction of aerobic respiration is –
$\underset { Glucose\quad }{ { C }_{ 6 }{ H }_{ 12 }{ O }_{ 6 } } \quad +\quad \underset { Oxygen }{ { 6O }_{ 2 } } \rightarrow \quad \underset { Carbondioxide\quad }{ { 6CO }_{ 2 } } +\quad \underset { Water }{ { 6H }_{ 2 }O } \quad +\quad \underset { Energy }{ ATP }$
Steps of aerobic reactions:
The aerobic reaction starts from the cytosol of a cell and completed in four steps:
Glycolysis: Glycolysis is the primary step of aerobic respiration and it takes place in the cytosol of the cells. During the glycolysis process, glucose is partially oxidized to form two molecules of pyruvic acid, two ATP, and two NADH molecules.
Oxidative decarboxylation of pyruvate: In this step, pyruvate synthesized from the glycolysis pathway enters into the mitochondrial matrix and undergoes oxidative decarboxylation catalyzed by pyruvic dehydrogenase. In this process, acetyl CoA and NADH are produced.
Tricarboxylic Acid (TCA) Cycle: In this cycle, the oxaloacetate combines with the acetyl-coenzyme A and produces citric acid. This reaction is catalyzed by the citrate synthase enzyme and a molecule of CoA is released. This cycle involves a series of reactions and finally produces 2 molecules of ${ CO }_{ 2 }$, 1 molecule of ATP, and reduced forms of NADH and FADH.
Electron Transport System: This is the last step of aerobic respiration that takes place in the inner mitochondrial membrane. In this process, the large amounts of ATP molecules are produced by transferring the electrons from NADH and FADH.

Note: In respiration generally, carbohydrates are oxidized to release energy but under certain conditions, proteins, fats, and organic acids can also be used as respiratory substances in some plants.
-Aerobic respiration occurs in every single multicellular organism including animals, plants, and other living organisms.