NCERT Based Test: Biomacromolecules


20 Questions MCQ Test NCERTs for NEET | NCERT Based Test: Biomacromolecules


Description
Attempt NCERT Based Test: Biomacromolecules | 20 questions in 20 minutes | Mock test for NEET preparation | Free important questions MCQ to study NCERTs for NEET for NEET Exam | Download free PDF with solutions
QUESTION: 1

Select the option that correctly identifies the chemical bonds present in the given biomolecules. 
Polysaccharides - A, Proteins - B, Fats - C, Water - D

Solution:

In polysaccharides, monosaccharides are linked together by glycosidic bond (C−O−C). It is formed by dehydration between two carbon atoms of two adjacent monosaccharides. Water has hydrogen bonding. Amino acids in a protein are linked through peptide bond whereas ester bond is present in fats.

QUESTION: 2

Which of the following is a heteropolymer?

Solution:

(i) Homopolysaccharids or homogycans are those complex carbohydrates which are formed by polymerisation of only one type of monosaccharide monomers.
For example: starch, glycogen and cellulose are composed of a single type of monosaccharide called glucose. similarly, chitin is composed of monomer units of N- acetylglucosamine. Depending upon monosaccharide unit involved, polysaccharide is called glucan (made of glucose ), fructan (made of fructose), xylan (having xylose) etc.
(ii) Heteropolysaccharides or heteroglycans are those complex carbohydrates which are produced by condensation of two or more types of monosaccharide derivatives,
For example: Agar, peptidoglycan, glycosaminoglycans, etc.

QUESTION: 3

In a DNA molecule, the phosphate group is attached to ____carbon of the sugar residue of its own nucleotide and _____ carbon of the sugar residue of the next nucleotide by ____bonds.

Solution:

A deoxyriboncleotide of DNA is formed by cross-linking of three chemicals- deoxyribose sugar (C5H10O4), a nitrogen base and phosphoric acid (H3PO4). The backbone of a DNA strand is built up of alternate deoxyribose and phosphoric acid grounds. The phosphate group is connected to carbon 5' of the sugar residue of its own nucleotide and cerbon 3' of the sugar residue of the next nucleotide by phosphodiester bonds.

QUESTION: 4

Which of the following statements is not correct regarding chitin?

Solution:

Chitin is the second most abundant polysaccharide (after cellulose). Chitin is not a storage polysaccharide rather it is a structural homopolysaccharide which forms the structure component of fungal walls and exoskeleton of artropods. It is an unbranched polysaccharide formed of N- acetylglucosamine (NAG) monomers joined together by β−1,4 linkages.

QUESTION: 5

Read the given statements and select the correct option.
Statement 1 :
Hemoglobin is an example of quatenary structure of proteins.
Statement 2 : Hemoglobin molecule is composed of four polypeptide chains-two α-chains and two β-chains.

Solution:

Proteins are said to have quaternary structure if they consist of 2 or more polypeptide chains untied by force other than covalent bonds (i.e., not peptide are hydrogen bonds). The force that stabilise these aggregates are hydrogen bonds and electrostatic bonds formed between amino acids on the polypeptide chains. Haemoglobin, the oxygen-transporting protein of blood, is an example of quaternary structure. This protein consists of four peptide chains of two types-α and β chains that occur in pairs.

QUESTION: 6

Match column I with column II and select the correct option from the given codes.

Solution:

A. Galactose is a monosaccharide which is also known as brain sugar. It is an important constituent of glycoprotein and glycolipids.
B. Anticoagulant is the substance that prevents coagulation of the blood cells and it is heparin which is obtained from leeches.
C. Fructose is important monosaccharide which is found in fruit juices and honey. It is the sweetest carbohydrate.
D. Lecithin is a phospholipid. Phospholipids are amphoteric molecules and contain phosphoric acid. Phospholipid help in transport, metabolism and permeability of the cell membrane.
E. Insulin is a protein which is made up of amino acids.

QUESTION: 7

Match Column-I with Column-II and select the correct option from the codes given.

Solution:

A. Cotton fibre is cellulose. The tainted form of cellulose is cotton and contains about 90% cellulose.

B. Exoskeleton of cockroach is Chitin. Chitin is the main component of the outer skeleton of the cockroaches and it is a fibrous material which consists of polysaccharides.  

C. Liver is glycogen which remains inside the body of animals in the form of stored energy.

D. Peeled potato is starch which is basically a sequence of units of glucose which is connected by glycosidic bonds.

E. Roots of Dahlia produces inulin, which can help the body deal with its own insulin needs. The Inulin molecules obtained from Dahlia tubers are called Dahlin. 

QUESTION: 8

B-DNA which is right-handed double helix contains ______ base pairs per turn of the helix and each turn is _______ long.

Solution:

In B-DNA, one turn of the helix has about 10 nucleotides on each strand of DNA. A turn occupies a distance of about 3.4 nm (34Å or 3.4×10−9m) so that adjacent nucleotides or their bases are separated by a space of about 0.34nm(0.34×10−9m or 3.4Å).

QUESTION: 9

The correct order of chemical composition of living tissues/cells in term of percentage of the total cellular mass is

Solution:

The average composition of a living cell is water 70−90%, proteins 10−15%, nucleic acids 5−7%, carbohydrates 3%, lipids 2%, ions 1%.

QUESTION: 10

Which bonds are indicated by X and Y in the given diagram?

Solution:

Given figure represents a part of DNA molecules, in which phosphoric acid groups and deoxyribose sugars are linked together by means of phosphodiester bonds. The two DNA chains are antiparallel, i.e., they run parallel but in opposite directions. In one chain the direction is 5'→3' while in the opposite one it is 3'→5'. The chains are held together by hydrogen bonds between their bases. Adenine (A), a purine of one chain lies exactly opposite to thymine (T), a pyrimidine of the other chain . Similarly, cytosine (C), a primidine lies opposite to guanine (G) a purine. Three hydrogen bonds occur between cytosine and guanine (C≡G) at positions 1'−1',2'−6' and 6'−2'. There are two such hydrogen bonds between adenone and thymine (A=T) which are formed at positions 1'−3' and 6'−4'. Hydrogen bonds occur between hydrogen of one base and oxygen or nitrogen of the other base.

QUESTION: 11

What will be the molecular formula of a polypeptide consisting of 10 glycine molecules when the formula of glycine is    C2H5​NO2?

Solution:

A polypeptide is formed by the condensation of glycine monomers, i.e., by the eliminetion of one water molecule during the formation of each peptide bond. When 10 glycine (C2H5O2N), molecules participate, 9H2O molecules are eliminated. Thus resulting polypeptide will prossess the molecular formula C20H32O11N10.

QUESTION: 12

An unknown liquid collected from a sample of peas, is added to a beaker of water and is vigorously shaken. After few minutes, water and the unknown liquid made two separate layers. To which class of biomolecules, does the unknown liquid most likely belongs?

Solution:

The term Lipid was coined by Bloor. Lipids are the esters of fatty acid and alcohol. These are hydrophobic that is these are insoluble in water but soluble in benzene, ether and chloroform. As these are insoluble in water when they are added with water they separate to form two layers.

QUESTION: 13

Study the given statements and select the correct answer.
(i) Cellulose is a homopolymer of glucose.
(ii) Inulin is a homopolymer of fructose.
(iii) Starch gives blue colour and glycogen gives red colour with iodine solution.
(iv) Cellulose gives no colour with iodine solution.

Solution:

Starch can hold I2 (iodine) molecules in the helical portion. The starch-I2 is blue in colour. Cellulose does not contain complex helices and hence cannot hold I2 and hence remain colourless.

QUESTION: 14

Read the given statement and select the option that correctly identifies X and Y.
In a glycogen molecule, successive glucose units are joined together by X and branches are linked together by Y.

Solution:

Glycogen is a branched polymer of glucose. Glucose residues are linked linearly by α-1, 4 glycosidic bonds (glycosidic bonds formed between C-1 of one glucose with the C-4 of the next). After every 10-14 units, a side chain branch occurs that attach at C-6 of a glucose unit by α-1, 6 glycosidic linkages.

QUESTION: 15

Which of the following secondary metabolites are used as drugs?

Solution:


Vinblastine is used as an anticancer drug whereas curcumin is a component of turmeric and also used as a drug.

QUESTION: 16

_____is the most abundant protein in animal world and ____is the most abundant protein in the whole biosphere.

Solution:

Collagen is a protein which is most abundant in the animal world and is a connective tissue and rubisco is an enzyme which is the most abundant protein in the whole biosphere because rubisco is the enzyme which is responsible for the sugar formation during photosynthesis.

QUESTION: 17

Read the given statements and select the correct option.
i. Right end of a polysaccharide chain is called reducing end while left end is called non-reducing end.
ii. Starch can hold iodine molecules in its helical secondary structure but cellulose being non-helical, cannot hold iodine.
iii. Starch and glycogen are branched molecules.
iv. Starch and glycogen are the reserve food materials of plants and animals, respectively.

Solution:

(i) The right end of the polysaccharide chain which has a free reactive end and is known as reducing and left side is the non-reducing end.
Starch is a polymer of glucose that is made up of two types of chains amylose and amylopectin.
(ii) Amylose is a straight polymer with 1-4 glycosidic linkages and amylopectin is a branched polymer with 1-6 glycosidic linkage.
(iii) Starch can hold iodine molecule in the amylopectin helical structure. Starch is the reserve food material in plants. Glycogen is also a storage food material in animals. It is also branched structure, a polymer of glucose which has linear 1-4 glycosidic bonds and branched 1-6 glycosidic linkage.
(iv) Cellulose is a linear polymer of Beta D glucose which does not trap iodine molecules.

QUESTION: 18

Refer the two reactions (i) and (ii) given below and select the correct option
(i) ADP + Pi → ATP
(ii) ATP → ADP + Pi

Solution:

(i) Endergonic reactions are the reactions which involve intake / absorption of energy. Exergonic reactions are the reactions which involve the release of energy. During ATP formation, energy is taken in and stored in the form of ATP; whereas energy is liberated during breakdown of ATP.
(ii) ADP + Pi + Energy ⇌ ATP reaction can occur in a cyclic manner of build up and break-down reactions.
(iii) ATP is called a high-energy molecule because it releases a large amount of usable energy when it loses its terminal phosphate group to become adenosine diphosphate (ADP).

QUESTION: 19

Read the given statements.
(i) Fructose is the sweetest sugar.
(ii) Glycine is the simplest amino acid.
(iii) Lactose is a disaccharide composed of one molecule each of glucose and galactose.
(iv) Cellulose is an unbranched chain of glucose molecules linked by β−1, 4-glycosidic bond.
Which of the given statements are correct?

Solution:

(i) Carbohydrate, on the basis of the number of molecules present, is divided into monosaccharides, disaccharide and polysaccharides. Fructose is also known as the fruit sugar and is a monosaccharide. It is a 6 carbon molecule. Glycine is the simplest amino acid as it contains hydrogen in the side chain. (ii) Lactose is a disaccharide which means it has two molecules of same or different monosaccharide units. Lactose is also known as the milk sugar. 
(iii) On hydrolysis, lactose produces glucose and galactose.
(iv) Cellulose is a polysaccharide and an important constituent of cell wall it is made up of Beta D glucose units linked by 1-4 glycosidic linkage.

QUESTION: 20

The regulation by an organism of chemical composition of its blood and body fluids and other aspects of its internal environment so that physiological processes can proceed at optimum rates is called

Solution:

Homeostasis is the regulation by an organism of the chemical composition of its body fluids and other aspects of its internal environment so that physiological processes can proceed at optimum rates.

Use Code STAYHOME200 and get INR 200 additional OFF
Use Coupon Code