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Class 12 Chemistry  MCQ Questions of Biomolecules with Answers?

Answer 1

 These important Class 12 Chemistry MCQ Questions of Biomolecules with Answers are prepared by our academic experts. MCQ Questions for class 12 make you feel confident in answering the question in the exam & if practiced properly can help you to get higher marks. The MCQ Questions for Class 12 Chemistry with Answers have been prepared as per the latest 2021 syllabus, NCERT books and exam pattern suggested in Class 12.

We have provided MCQ Questions for class 12 Chemistry Biomolecules with Answers to help students understand the concept very well and understand pattern of questions. Practice the given MCQ Questions for Class 12 Chemistry with Answers.

Practice MCQ Question for Class 12 Chemistry chapter-wise

1. On oxidation with a mild oxidising agent like Br₂/H₂O, the glucose is oxidized to

(a) saccharic acid
(b) glucaric acid
(c) gluconic acid
(d) valeric acid

2. Invert sugar is

(a) a type of cane sugar
(b) optically inactive form of sugar
(c) mixture of glucose and galactose
(d) mixture of glucose and fructose in equimolar quantities

3. Glycosidic linkage is an

(a) amide linkage
(b) ester linkage
(c) ether linkage
(d) acetyl linkage

4. Which reagent is used to convert glucose into saccharic acid?

(a) Br₂ / H₂O
(b) Nitric acid
(c) Alkaline solution of iodine
(d) Ammonium hydroxide

5. Which of the following is an example of an aldopentose?

(a) D-Ribose
(b) Glyceraldehyde
(c) Fructose
(d) Erythrose

6. Carbohydrates are stored in human body as the polysaccharide

(a) starch
(b) glycogen
(c) cellulose
(d) amylose

7. Which one of the amino acids can be synthesized in the body?

(a) Alanine
(b) Lysine
(c) Valine
(d) Histidine

8. Which of the following gives positive Fehling solution test?

(a) Protein
(b) Sucrose
(c) Glucose
(d) Fats

9. Glucose gives silver mirror test with Tollen’s reagent. It shows the presence of

(a) acidic group
(b) alcoholic group
(c) ketonic group
(d) aldehyde group

10. The two functional groups present in a typical carbohydrate are:

(a) – CHO and – COOH
(b) > C = O and – OH
(c) – OH and – CHO
(d) – OH and – COOH

11. Glucose reacts with acetic anhydride to form

(a) monoacetate
(b) tetra-acetat
(c) penta-acetate
(d) hexa-acetate

12. Which of the following is a disaccharide?

(a) Lactose
(b) Starch
(c) Cellulose
(d) Fructose

13. Which of the following monosaccharide is pentose?

(a) Glucose
(b) Fructose
(c) Arabinose
(d) Galactose

14. Which among the following is the simplest sugar?

(a) Glucose
(b) Starch
(c) Cellulose
(d) None of these

15. Glucose does not react with

(a) Br₂ / H₂O
(b) H₂NOH
(c) HI
(d) NaHSO₃

16. Isomerization of glucose produces

(a) galactose
(b) fructose
(c) mannose
(d) allose

17. The sugar present in fruits is

(a) fructose
(b) glucose
(c) sucrose
(d) galactose

18. The number of chiral carbon atoms present in cyclic structure Answer :-D(+) glucose

(a) 3
(b) 4
(c) 5
(d) 6

19. The couplings between base units of DNA is through : 

(a) Hydrogen bonding
(b) Electrostatic bonding
(c) Covalent bonding
(d) Van der wall's forces

20. The segment of DNA which acts as the instrumental manual for the synthesis of the protein is 

(a) nucleotide
(b) ribose
(c) gene
(d) nucleoside

21. The number of molecules of ATP produced in the lipid metabolism of a molecule of palmitic acid is

(a) 130
(b) 36
(c) 56
(d) 86

22. An amine among the following that acts as hormone is : 

(a) Thyroxine
(b) Oxypurin
(c) Insulin
(d) Progesterone

23. Which amino acid does not contain a chiral center?

(a) Valine
(b) Leucine
(c) Glycine
(d) Iso-leucine

24. Which of the following contains the highest percentage of protein?

(a) Groundnut
(b) Cow’s milk
(c) Egg
(d) Wheat

25. Which is fat soluble vitamin?

(a) Vitamin A
(b) Pyridoxine
(c) Riboflavin
(d) Thiamine

Answer 2

1. Answer : (c) gluconic acid

Explanation: Glucose gets oxidised to gluconic acid on reaction with mild oxidising agent like bromine water.

2. Answer : (d) mixture of glucose and fructose in equimolar quantities

Explanation: Sucrose on hydrolysis gives glucose and fructose in the same number of moles. - Sucrose during the process of hydrolysis brings about a change in optical rotation and that's why the products are known as invert sugar. - Therefore, an invert sugar is a mixture of glucose and fructose in equimolar quantities.

3. Answer : (c) ether linkage

Explanation: A glycosidic bond is formed between the hemiacetal group of saccharide and the hydroxyl group of another compound like an alcohol. This is a covalent bond which links carbohydrate (sugar) to other compounds which may or may not be a carbohydrate. So, glycosidic linkage contains an ether linkage.

4. Answer : (b) Nitric acid

Explanation: The nitric acid being a strong oxidising agent, it can oxidise the alcohol and the aldehyde. Thus, in the glucose the C-1 and C-6 have the aldehydic and the primary alcohol to oxidise into carboxylic acid forming the saccharic acid compound.

5. Answer : (a) D-Ribose

Explanation: Ribose is an aldopentose. It contains an aldehydic group and five carbon atoms.

6. Answer : (b) glycogen

Explanation:The glycogen is a multibranched polysaccharide of glucose, allowing its rapid dissemination and serving as the main storage form of glucose in the body.

7. Answer : (a) Alanine

Explanation: Six amino acids are non-essential (dispensable) in humans, meaning they can be synthesized in sufficient quantities in the body. These six are alanine, aspartic acid, asparagine, glutamic acid, serine, and selenocysteine (considered the 21st amino acid).

8. Answer : (c) Glucose

Explanation: The Glucose structure has an aldehyde group and due to which it gives a positive test for Fehling's solution.

9. Answer : (d) aldehyde group

Explanation: Glucose gives silver mirror test with Tollen's reagent. It is due to the presence of an aldehydic group (-CHO group).

10. Answer : (c) – OH and – CHO

Explanation: Carbohydrates are essentially polyhydroxy aldehydes and polyhydroxy ketones. Thus, the two functional groups present are (aldehyde or ketone) and -OH (hydroxy) groups.

11. Answer : (c) penta-acetate

Explanation: Glucose reacts with acetic anhydride to form penta- acetate as a molecule of glucose contains five -OH groups.

12. Answer : (a) Lactose

Explanation: Starch and cellulose are polysaccharides, fructose is monosaccharide and lactose is disaccharide.

13. Answer : (c) Arabinose

Explanation: Arabinose is pentose monosaccharide while glucose, fructose and galactose are hexose sugar.

14. Answer : (a) Glucose

Explanation: Glucose is a simple sugar with six carbon atoms and one aldehyde group. Glucose (C₆H₁₂O₆) is an example of a carbohydrate monomer or monosaccharide.

15. Answer : (d) NaHSO₃

Explanation: Glucose consists of an aldehyde group. However, it does not undergo reaction with sodium hydrogen sulphite in order to form bisulphite addition products.

16. Answer : (b) fructose

Explanation:​​​​​​​ The isomerization of glucose to fructose is carried out industrially with pH-neutral glucose solutions [4], which have a higher glucose concentration than process waters from the acid-catalyzed pretreatment of lignocellulose (hydrolysates).

17. Answer : (a) fructose

Explanation: Fruit contains two types of sugar: fructose and glucose. The proportions of each vary, but most fruits are about half glucose and half fructose.

18. Answer : (c) 5

Explanation: The open chain contains four chiral carbons and the cyclic form of glucose contains five chiral carbons.

19. Answer : (a) Hydrogen bonding

Explanation: In DNA the two strands are held together by hydrogen bonds. For example guanine is bonded to cytosine and adenine to thymine by hydrogen bonding.

20. Answer : (c) gene

Explanation: The segment of DNA Which acts as the instrumental manual for the synthesis of the protein is a gene. Every protein in a cell has a corresponding gene.

21. Answer : (a) 130

Explanation: The number of molecules of ATP (Adenosine triphosphate) produced in lipid metabolism of a molecule of palmitic acid is 130. Monosaccharide ribose is an ATP, which acts as energy currency of the cells during metabolism of carbohydrates, protein and fats.

22. Answer : (a) Thyroxine

Explanation: The hormone which is proteinous nature are said to be amine hormone because protein is the polymers of polypeptides and polypeptides are made up of amino acids. An amino acid contains amino group.Thyroxin is an amine hormone. It is secreted by the thyroid gland. Its function is to control the metabolism of carbohydrates, proteins and lipids.

23. Answer : (c) Glycine

Explanation: Glycine is the only amino acid with no chiral carbon (asymmetric carbon).

24. Answer : (a) Groundnut

Explanation: An average-sized egg contains about 6–7 grams of protein. in cow milk protein about 3.5 percent and Because several varieties of wheat are commonly grown, the protein content can vary from 9 to 15 percent. And in groundnut the protein content ranges from 22–30% of its total calories, making peanuts a great source of plant-based protein.

25. Answer : (a) Vitamin A

Explanation: Fat-soluble vitamins are absorbed along with fats in the diet and are stored in the body's fatty tissue and in the liver. They are found in many plant and animal foods and in dietary supplements. Vitamins A, D, E, and K are fat-soluble.

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