What is fermentation with diagram and explaination
Answers
Answer:
- Fermentation is a metabolic process that produces chemical changes in organic substrates through the action of enzymes.
- In biochemistry, it is narrowly defined as the extraction of energy from carbohydrates in the absence of oxygen.
Explanation:
- Fermentation is the process in which a substance breaks down into a simpler substance.
- Microorganisms like yeast and bacteria usually play a role in the fermentation process, creating beer, wine, bread, kimchi, yogurt and other foods.
- Grape juice becomes wine as the fermentation process is complete.
Answer:
Apart from fermentation, living things produce chemical energy by degrading sugar molecules (e.g. glucose) through aerobic respiration and anaerobic respiration. Aerobic respiration uses oxygen, hence, the term ”aerobic”. It has three major steps. First, it begins with glycolysis wherein the 6-carbon sugar molecule is lysed into two 3-carbon pyruvate molecules. Next, each pyruvate is converted into acetyl coenzyme A to be broken down to CO2 through the citric acid cycle. Along with this, the hydrogen atoms and electrons from the carbon molecules are transferred to the electron-carrier molecules, NADH, and FADH2. Then, these electron carriers shuttle the high-energy electrons to the electron transport chain to harness the energy and synthesize ATP. The final electron acceptor in the chain is oxygen. As for anaerobic respiration, this form of respiration does not require oxygen. However, it is similar to aerobic respiration in a way that the electrons are passed along the electron transport chain to the final electron acceptor. In anaerobic respiration, the bottom of the chain is not oxygen but other molecules, for example, sulfate ion (SO4–2) or nitrate ion (NO3–).
Some people consider fermentation as an example or part of anaerobic respiration as both of them do not use oxygen, and therefore, are anaerobic. However, anaerobic respiration and fermentation are two different processes. Fermentation skips the electron transport chain system. After glycolysis, pyruvate (in lactic acid fermentation) or acetaldehyde (in alcohol fermentation) serves as the final electron acceptor.
The type of fermentation depends on its byproducts. For example, lactic acid fermentation is a type of fermentation that produces lactic acid. Alcohol fermentation produces alcohol, such as ethanol, aside from CO2.
Fermentation occurs in prokaryotes and eukaryotes, including humans. Our body resorts to fermentation when there is a high energy demand while the oxygen supply becomes limited. An example of this is when we do a strenuous exercise. The muscle cells generate ATP to supply energy via aerobic respiration. But when the ATP demand in the muscle cells outruns the blood supply of oxygen, the muscle cells resort to lactic acid fermentation so that they can continue providing energy while the supply of oxygen is limited. When the oxygen level returns to normal, they go back to aerobic respiration.
While fermentation is only an alternative pathway in generating ATP, some organisms, such as obligate anaerobes, rely on fermentation to biosynthesize ATP. The genus Neocallimastix is an example of obligate anaerobes. The fungi in this genus are found in the rumen of herbivorous animals. As symbionts, they help digest cellulose through fermentation. (Ref. 1) Another example of obligate anaerobe is the genus Bacteroides. This genus consists of obligate anaerobes that are part of human colonic flora. (Ref. 2) They degrade sugar derivatives from plant materials and generate energy through fermentation.