Q.11. What are the byproducts(end products) obtained in the following cases: - (4)
A anaerobic respiration in yeast
B. aerobic respiration
C Carbon dioxide passed through lime water
D Iron nail is dipped in copper sulphate solution
Answers
Answer:
Introduction
Ever wonder how yeast ferment barley malt into beer? Or how your muscles keep working when you're exercising so hard that they're very low on oxygen?
Both of these processes can happen thanks to alternative glucose breakdown pathways that occur when normal, oxygen-using (aerobic) cellular respiration is not possible—that is, when oxygen isn't around to act as an acceptor at the end of the electron transport chain. These fermentation pathways consist of glycolysis with some extra reactions tacked on at the end. In yeast, the extra reactions make alcohol, while in your muscles, they make lactic acid.
Fermentation is a widespread pathway, but it is not the only way to get energy from fuels anaerobically (in the absence of oxygen). Some living systems instead use an inorganic molecule other than \text {O}_2O
2
start text, O, end text, start subscript, 2, end subscript, such as sulfate, as a final electron acceptor for an electron transport chain. This process, called anaerobic cellular respiration, is performed by some bacteria and archaea.
In this article, we'll take a closer look at anaerobic cellular respiration and at the different types of fermentation.
Anaerobic cellular respiration
Anaerobic cellular respiration is similar to aerobic cellular respiration in that electrons extracted from a fuel molecule are passed through an electron transport chain, driving \text{ATP}ATPstart text, A, T, P, end text synthesis. Some organisms use sulfate (\text {SO}_4^{2-})(SO
4
2−
)left parenthesis, start text, S, O, end text, start subscript, 4, end subscript, start superscript, 2, minus, end superscript, right parenthesis as the final electron acceptor at the end ot the transport chain, while others use nitrate (\text {NO}_{3}^-)(NO
3
−
)left parenthesis, start text, N, O, end text, start subscript, 3, end subscript, start superscript, minus, end superscript, right parenthesis, sulfur, or one of a variety of other molecules^1
1
start superscript, 1, end superscript.
What kinds of organisms use anaerobic cellular respiration? Some prokaryotes—bacteria and archaea—that live in low-oxygen environments rely on anaerobic respiration to break down fuels. For example, some archaea called methanogens can use carbon dioxide as a terminal electron acceptor, producing methane as a by-product. Methanogens are found in soil and in the digestive systems of ruminants, a group of animals including cows and sheep.
Similarly, sulfate-reducing bacteria and Archaea use sulfate as a terminal electron acceptor, producing hydrogen sulfide (\text H_2\text S)(H
2
S)left parenthesis, start text, H, end text, start subscript, 2, end subscript, start text, S, end text, right parenthesis as a byproduct. The image below is an aerial photograph of coastal waters, and the green patches indicate an overgrowth of sulfate-reducing bacteria.
Explanation: