what is the difference between aerobic and anaerobic respiration
Answers
Answer:
Aerobic respiration is a set of metabolic reactions that take place in the presence of oxygen, occurring in a cell to convert chemical energy into ATPs.
Aerobic respiration takes place in all plants, animals, birds, and humans, except for some primitive prokaryotes.
In aerobic respiration, oxygen acts as an electron acceptor which helps produce ATPs more effectively and more quickly.
The double bond in the oxygen has higher energy than other bonds which aids to produce more ATPs.
It is the preferred method of degradation of pyruvate after glycolysis where the pyruvate then enters the mitochondria to be fully oxidized during the Kreb’s cycle.
The process of aerobic respiration is utilized for the oxidation of carbohydrates, but products from fats and proteins are also used as reactants.
Carbon dioxide gas and water are the two products of aerobic respiration along with the energy that is used to add a third phosphate group to ADP and form ATP.
Other energy-rich molecules like NADH and FADH2 are converted into ATP via electron transport chain with oxygen and protons.
During aerobic respiration, most ATPs are produced during oxidative phosphorylation where the energy of oxygen molecule is used to pump protons out of the membrane.
The passage of protons creates a potential that is then used to initiate ATP synthase and produce ATP from ADP and a phosphate group.
Ideally, a total of 38 ATPs are produced at the end of the aerobic respiration. However, some energy is lost due to leaking of the membrane or the cost of moving pyruvate through the cell, as a result of which about 29-30 ATPs are only produced.
Aerobic respiration results in complete oxidation of carbohydrate molecules which take place in the mitochondria of eukaryotic cells as the enzymes for the process are present there.
Anaerobic Respiration Definition
Anaerobic respiration is a process of cellular respiration where the high energy electron acceptor is neither oxygen nor pyruvate derivatives.
In anaerobic respiration, the electron acceptor can be sulfate ion (SO4–) or nitrate ion (NO3–) or a variety of other molecules.
Some archaea, called methanogens, are known to use carbon dioxide as the electron acceptor, producing methane as a by-product.
Similarly, another group of purple sulfur bacteria uses sulfate as an electron acceptor, thus producing hydrogen sulfide as a by-product.
These organisms reside in low-oxygen environments and thus opt for anaerobic pathways to break down the chemical fuels.
Anaerobic respiration is similar to aerobic respiration in that the molecules enter the electron transport chain to pass the electrons to the final electron acceptor.
The final electron acceptors involved in anaerobic respiration have a smaller reduction potential than oxygen molecules which results in less energy production.
Anaerobic respiration, however, is essential for biogeochemical cycles of carbon, nitrogen, and sulfur.
The nitrate that acts as an electron acceptor in anaerobic respiration produces nitrogen gas as a by-product, and this process is the only route for fixed nitrogen to reach the atmosphere.
Fermentation is another pathway for anaerobic respiration, where the only energy extraction pathway is glycolysis, and the pyruvate is not further oxidized via the citric acid cycle.
The energy-rich molecule, NADH, is also not utilized during fermentation.
Anaerobic respiration takes place in many environments like freshwater, soil, deep-sea surfaces. Some microbes in oxygenated environments also utilize anaerobic respiration because oxygen cannot readily diffuse through their surface.
Anaerobic respiration and fermentation, both take place in the cytoplasm of the prokaryotic cell.
Anaerobic respiration and fermentation processes take place in the muscle cells during immediate contraction and relaxation.
Fermentation results in a total gain of only two ATPs per glucose molecule.
Aerobic respiration is a set of metabolic reactions that take place in the presence of oxygen, occurring in a cell to convert chemical energy into ATPs.
Anaerobic respiration is a process of cellular respiration where the high energy electron acceptor is neither oxygen nor pyruvate derivatives.