Tag: biology

Questions Related to biology

An enzyme used in cheese making is

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  1. Protease

  2. Rennet

  3. Glucoamylase

  4. Lactase

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Correct Option: B
Explanation:
Animal rennet (bovine chymosin) is conventionally used as a milk-clotting agent in dairy industry for the manufacture of quality cheeses with good flavour and texture. Owing to an increase in demand for cheese production world wide, i.e., 4% per annum over the past 20 years, approximating 13.533 million tons – coupled with reduced supply of calf rennet, has therefore led to a search for rennet substitutes, such as microbial rennets. At present, microbial rennet is used for one-third of all the cheese produced world wide.
Thus, the correct answer is option B.

Yeast is used in the formation of 

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  1. Ammonia

  2. Alcohol

  3. Curd

  4. Petrol

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Correct Option: B
Explanation:

Ethanol fermentation is a biological process to produce ethanol and carbon dioxide as metabolic waste products. Because yeasts perform this conversion in the absence of oxygen, alcoholic fermentation is considered an anaerobic process. 

Thus, the correct answer is option B.

Which one of the following is used in the manufacture of alcohol?

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  1. Bacteria

  2. Water molds

  3. Yeasts

  4. Slime molds

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Correct Option: C
Explanation:
The overall process of fermentation is to convert sugar glucose (C$ _6$H$ _{12}$O$ _6$) to an alcohol (CH$ _3$CH$ _2$OH) and carbon dioxide gas (CO$ _2$). The reactions within the yeast to make this happen are very complex but the overall process is as follows: C$ _6$H$ _{12}$O$ _6$ ====> 2(CH$ _3$CH$ _2$OH) + 2(CO$ _2$)
 Sugar ====> Alcohol + Carbon dioxide gas. 
The most important type of fermentation is alcoholic fermentation, in which the action of zymase secreted by yeast converts simple sugars, such as glucose and fructose, into ethyl alcohol and carbon dioxide.

Saccharomyces is commonly used in the production of

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  1. Ethyl alcohol

  2. Curd

  3. Citric acid

  4. Acetic acid

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Correct Option: A
Explanation:

Saccharomyces cerevisiae (Common name is Baker's or brewer's yeast) is a species of yeast generally used in the production of ethyl alcohol in beer and wine making process. In the production of ethyl alcohol, the fungus Saccharomyces produces the enzyme zymase. This zymase will then acts on Glucose to produce ethyl alcohol. Thus, the correct answer is option A.

Lactic acid bacteria (LAB) at suitable temperature converts milk to curd, which improves its nutritional quality by enhancing vitamin

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  1. A

  2. B

  3. C

  4. D

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Correct Option: B
Explanation:

Dairy products have generally been considered an excellent source of high-quality protein, calcium, potassium, phosphorus, magnesium, zinc, and the B vitamins riboflavin, niacin, vitamin B-6, and vitamin B-12. The final nutritional composition of yogurt is affected by the species and strains of bacteria used in the fermentation, the source and type of milk solids that may be added before fermentation, and the temperature and duration of the fermentation process.

In olden days, cheese was prepared by

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  1. Aspergillus

  2. Rennet enzyme

  3. Clostridium bacteria

  4. None of the above

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Correct Option: B
Explanation:

Traditional animal rennet is an enzyme derived from the stomachs of calves, lambs or goats. Rennet is used in the production of most cheeses. Chymosin, its key component, is a protease enzyme that curdles the casein in milk. 

In the formation of ascorbic acid, the micro-organism used is

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  1. Acetobacter

  2. Streptomyces sp.

  3. Bacillus megatherium

  4. Propioni bacterium

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Correct Option: A
Explanation:

Acetobacter suboxydans is a gram-negative bacteria of the order rhodospirilla. It is used in the formation of ascorbic acid. A. suboxydans is widely used commercially in the production of ketonic acids like ascorbic acid (Vitamin C). 

In the production of leavened bread, the following is used

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  1. Bacterium

  2. Yeast

  3. Rhizopus

  4. None of the above

  5. Both (A) and (B)

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Correct Option: E
Explanation:

Sourdough (leavened bread) is a bread product made by a long fermentation of dough using naturally occurring Lactobacilli and yeasts. The most commonly used yeast species in the production of sourdough are Kazanchastania exigua (Saccharomyces exiguous), Saccharomyces cerevisiae, Candida Milleri, and Candida humilis

Germinating barley seeds are employed in the preparation of

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  1. Cheese

  2. Wine

  3. Beer

  4. Lactic acid

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Correct Option: C
Explanation:

Malted barley is barley that has been allowed to germinate (sprout) to a degree and is then dried. The germination process converts starch, the seed's stored energy, into simpler sugars used in its initial growing stage. The conversion of starch to sugar is accomplished by diastase enzymes that the seed produces during this process. The germination and drying stages capture fermentable sugars, soluble starch, and the diastase enzymes for beer brewing. 

Which of the following organic acids was produced by fermentation?

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  1. Oxalic acid

  2. Lactic acid

  3. Citric acid

  4. Propionic acid

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Correct Option: B
Explanation:

Lactic acid fermentation is a biological process by which glucose and other six-carbon sugars are converted into cellular energy and the metabolite lactate. Lactic acid fermentation is caused by some fungi and bacteria. The most important lactic acid producing bacteria is Lactobacillus. The presence of lactic acid, produced during the lactic acid fermentation is responsible for the sour taste and for the improved microbiological stability and safety of the food. This lactic acid fermentation is responsible for the sour taste of dairy products such as cheese, yoghurt