Tag: life processes in living organisms- part 1

Answer is option A i.e. "Pasteur effect"
Pasteur effect is exhibited in yeast cells during anaerobic fermentation. Pasteur effect influences the rate of glycolysis and occurs in presence of oxygen which  decreases the rate of sugar breakdown in yeast.
While, Blackman's law and Emerson effect is related to determining the rate of  photosynthesis. Chargraff's rule is a rule for base equivalence in DNA.

Fermentation is a type of anaerobic respiration that occurs in both plants and animals in the absence of oxygen. The end product is ethyl alcohol in plants and lactic acid in animal cells along with release of CO$ _2$ and energy. Fermentation is not as much energy yielding as aerobic respiration.

Fermentation is a type of anaerobic respiration in which the breakdown of glucose takes place to release acids, alcohols and other gases in absence of oxygen. It takes place in the cytoplasm.

Fermentation is an energy releasing process in which substrate like sugar is oxidized into organic acids or alcohol without an external electron acceptor. The final electron acceptor is either acetaldehyde or pyruvate. Aerobic respiration is a process in which energy is produced in the presence of oxygen. Glycolysis is a process of converting glucose into two molecules of pyruvate. Photorespiration is a process in which RuBisCO enzyme oxygenates RuBP by wasting some amount of energy.

The process of respiration can be aerobic or anaerobic. The process of anaerobic respiration is also called fermentation. Fermentation is a form of anaerobic respiration in which carbohydrates are incompletely oxidised to either ethanol and carbon dioxide as in yeast or lactic acid as in the muscles of higher vertebrates.

Fermentation is an anaerobic process in which energy can be released from glucose even though oxygen is not available. Fermentation occurs in yeast cells, and a form of fermentation takes place in bacteria and in the muscle cells of animals. So, the correct answer is option A.

Respiration is of two types :

• Fermentation is the process that takes place after the glycolysis in the cells where the anaerobic respiraton occurs due to absence or lack of oxygen.
• Pyruvic acid which is formed at the end of the glycolysis by the break down of the glucose molecule enters the fermentation reaction in the anaerobic cells.
• During fermentation reaction the pyruvic acid is converted to lactic acid and one molelcule of NADH is formed per molecule of pyruvic acid.
• This molecule of NADH will only form ATP when it will undergo oxidative phosphorylation in the electron transport chain which takes place in mitochondria, but for this process presence of oxygen is required so the organisms or the cells performing anaerobic respiration cannot perforem this process therefore the NADH formed will not donate electron to the ETS and no ATP will be formed by that.
• Therefore the answer option 'NADH donates electrons to electron transport system' is correct.