Question

QUESTION 20oF23- NOW LAB WORK When the E. coll grew in the anaerobic jar, how did these bacteria obtain energy? Decamposition of axypen radicals Trasport of hydrogen s

Answer 1

E.coli grown in anaerobic jar obtains energy from-

Answer- Fermentation.

Explanation- E.coli is a gram negative bacteria, it is a facultative anaerobe it means it produces ATP or energy when oxygen is present by aerobic respiration and is also able to switch to fermentation or anaerobic respiration in absence of oxygen.

Here in the question the E.coli bacteria is grown in an anaerobic jar, this means the jar does not contain any oxygen, so bacteria adopts anaerobic respiration or fermentation, and energy produced by this.

So option-B that is fermentation is the correct answer.

Option-A says it obtains energy by decomposition of oxygen radicals, but this statement is wrong because oxygen radicals are produced in aerobic life cycle, in absence of oxygen they are not produced.

Option-c that is it obtains energy by transport of hydrogen ions is also incorrect because transport of hydrogen ions occurs in aerobic respiration. In case of aerobic gram-ve e.coli glucose is oxidised in cytosol by a complex series of reaction that is glycolysis and kerb’s cycle, here hydrogen atoms are removed from glucose and carrier molecules transfer them into the inner membrane of mitochondria. Where Electron transport chain takes place, by the electron transport chain electrons are separated from hydrogen atoms and hydrogen ions (H⁺) are produced. Energy provided by electrons flowing through ETC is used to pump Hydrogen ions across the inner membrane to periplasm (the compartment between inner and outer membrane of mitochondria). as it is a part of aerobic respiration, it will not be able to help e.coli in producing energy in anaerobic condition.

Option-D that is aerobic respiration is also incorrect because in absence of oxygen aerobic respiration does not take place.