Tick the correct answer.
(a) Yeast is used in the production of
(i) sugar
(ii) alcohol
(iii) hydrochloric acid
(iv) oxygen
(b) The following is an antibiotic
(i) Sodium bicarbonate
(ii) Streptomycin
(iii) Alcohol
(iv) Yeast
(c) Carrier of malaria-causing protozoan is
(i) female Anopheles mosquito
(ii) cockroach
(iii) housefly
(iv) butterfly
(d) The most common carrier of communicable diseases is
(i) ant
(ii) housefly
(iii) dragonfly
(iv) spider
(e) The bread or idli dough rises because of
(i) heat
(ii) grinding
(iii) growth of yeast cells
(iv) kneading
(f) The process of conversion of sugar into alcohol is called
(i) nitrogen fixation
(ii) moulding
(iii) fermentation
(iv) infection

AcademicBiologyNCERTClass 8

(a) Yeast is used in the production of (ii) alcohol.

(b) The following is an antibiotic (ii) Streptomycin

(c) Carrier of malaria-causing protozoan is (i) female Anopheles mosquito

(d) The most common carrier of communicable diseases is (ii) housefly

(e) The bread or idli dough rises because of (iii) the growth of yeast cells

(f) The process of conversion of sugar into alcohol is called (iii) fermentation.

Explanation:

Fermentation is an enzyme-catalyzed metabolic process in which an organism converts carbohydrates, such as starch or sugar, into alcohol or acid, anaerobically releasing energy.

The study of fermentation is called "zymology."

For example, Alcohol Fermentation: It is used in the industrial production of wine, beer, biofuel, etc. The end product is alcohol and CO2.                                          

                                                        C6H12O6 --------->  2 C2H5OH + 2 CO2


Pyruvic acid breaks down into ethyl alcohol (C2H5OH) and carbon dioxide (CO2) is released.


Yeast and some bacteria carry out this type of fermentation where enzymes pyruvic acid decarboxylase and alcohol dehydrogenase act as catalysts.

raja
Updated on 10-Oct-2022 12:46:40

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