Biomolecules

Question 1

Most of the carbohydrates have a general formula……

Answer 1

Cx(H2O)y

Question 2

Assertion: All the compounds which fit into general formula may not be classified as carbohydrates.
Reason: Acetic acid (CH3COOH) fits into this general formula, C2(H2O)2 but is not a carbohydrate.

Answer 2

Correct and correct explanation

Question 3

………….. C6H12O5 is a carbohydrate but does not fit in this definition

Answer 3

Rhamnose

Question 4

Chemically, the carbohydrates may be defined as optically active polyhydroxy……./……or the compounds which produce such units on hydrolysis

Answer 4

aldehydes or ketones

Question 5

The carbohydrates, which are sweet in taste, are also called….

Answer 5

sugars

Question 6

Name some monosaccharides

Answer 6

Glucose
Galactose
Fructose

Question 7

Name some disaccharide

Answer 7

Maltose: Glucose + Fructose
Sucrose = glucose + glucose
Lactose= glucose + galactose

Question 8

Glucose Is aldohexose while the fructose is ketohexose

Answer 8

True
Glucose has aldehyde group and fructose has ketone group

Question 9

Glucose and fructose can be distinguished by…………. And not by …./…/…

Answer 9

Bromine water

Tollens/ benidicts/fehlings reagents

Question 10

Assertion: Glucose fructose and mannose give same osazone
Reason: Osazone is formed at first two carbon atoms.

Answer 10

Correct and correct explanation

Question 11

Osazone is stabilised by

Answer 11

Intra molecular hydrogen bond

Question 12

Fructose is reducing sugar and reduces TOLLENS REAGENT because

Answer 12

Enolisation of fructose followed by conversion to aldehyde by base

Question 13

Raffinose is composed of 3 monosaccharides

Answer 13

Glucose + galactose + fructose

Question 14

A polypeptide with more than hundred amino acid residues, having molecular mass higher than 10,000u is called a……..

Answer 14

protein

Question 15

Assertion: Polypeptides with fewer amino acids are likely to be called proteins .
Reason: In case they ordinarily have a well defined conformation of a protein such as insulin which contains 51 amino acids.

Answer 15

Both are correct and correct explanation

Question 16

Amino acids are usually

Answer 16

Colourless
Crystalline solids
Water-soluble
High melting solids
Behave like salts rather than simple amines or carboxylic acids.

Question 17

Statement 1:Most naturally occurring amino acids have L-configuration. Statement 2: L-Aminoacids are represented by writing the –NH2 group on left hand side.

Answer 17

Both are correct

Question 18

When carboxyl group of glycine combines with the amino group of alanine we get a dipeptide…….

Answer 18

glycylalanine

Question 19

Fibrous proteins

Answer 19

Run parallel
Held together by hydrogen and disulphide bonds, then fibre– like structure is formed.
Generally insoluble in water.
Keratin (present in hair, wool, silk) and myosin (present in muscles), etc.

Question 20

Globular proteins

Answer 20

Chains of polypeptides coil around to give a spherical shape.
Soluble in water.
Eg Insulin and albumins

Question 21

α-Helix is one of the most common ways in which a polypeptide chain forms all possible hydrogen bonds by twisting into a right handed screw (helix) with the –NH group of each amino acid residue hydrogen bonded to the carbonyl group of an adjacent turn of the helix

Answer 21

True

Question 22

Protein found in a biological system with a unique three-dimensional structure and biological activity is called a……..

Answer 22

native protein

Question 23

During denaturation 2° and 3° structures are destroyed but 1º structure remains intact

Answer 23

True

Question 24

The coagulation of egg white on boiling is a common example of denaturation

Answer 24

True

Question 25

The curdling of milk which is caused due to the formation of lactic acid by the bacteria present in milk is an example of

Answer 25

Denaturation

Question 26

Almost all the enzymes are……. proteins

Answer 26

globular

Question 27

Statement 1: The enzymes are said to reduce the magnitude of activation energy Statement 2: The activation energy for acid hydrolysis of sucrose is 6.22 kJ mol–1, while the activation energy is only 2.15 kJ mol–1 when hydrolysed by the enzyme, sucrase

Answer 27

Both are correct

Question 28

It has been observed that certain organic compounds are required in small amounts in our diet but their deficiency causes specific diseases These are called as

Answer 28

Vitamins

Question 29

Most of the vitamins cannot be synthesised in………. but……. can synthesise almost all of them, so they are considered as essential food factors

Answer 29

our body plants

Question 30

Assertion: The term “Vitamine” was coined from the word vital + amine Reason : The earlier identified compounds had amino groups.

Answer 30

Both are correct and correct explanation Later work showed that most of them did not contain amino groups, so the letter ‘e’ was dropped and the term vitamin is used these days.

Question 31

Assertion: Water soluble vitamins must be supplied regularly in diet Reason: They are readily excreted in urine and cannot be stored (except vitamin B12) in our body

Answer 31

Both are correct and correct explanation

Question 32

Assertion: Fingerprints have been used for identification for a long time Reason: Every individual has unique fingerprints.

Answer 32

Both are correct and correct explanation

Question 33

Assertion: Fingerprints for identification have drawbacks these days Reason: These can be altered by surgery.

Answer 33

Both are correct and correct explanation

Question 34

A sequence of bases on DNA is also unique for a person and information regarding this is called………

Answer 34

DNA fingerprinting It is same for every cell and cannot be altered by any known treatment

Question 35

DNA fingerprinting is now used

Answer 35

(i) in forensic laboratories for identification of criminals. (ii) to determine paternity of an individual. (iii) to identify the dead bodies in any accident by comparing the DNA’s of parents or children. (iv) to identify racial groups to rewrite biological evolution

Question 36

Why cannot vitamin C be stored in our body?

Answer 36

Vitamin C cannot be stored in the body because it's a water-soluble vitamin. This means it dissolves in water and any excess that's not immediately used is excreted through urine.

Question 37

What products would be formed when a nucleotide from DNA containing thymine is hydrolysed?

Answer 37

When a nucleotide from DNA containing thymine is hydrolyzed, the products are thymine, 2-deoxy-D-ribose, and phosphoric acid. Hydrolysis breaks down the nucleotide into its three basic components

Question 38

When RNA is hydrolysed, there is no relationship among the quantities of different bases obtained. What does this fact suggest about the structure of RNA?

Answer 38

RNA is single-stranded.

Question 39

The melting points and solubility in water of amino acids are generally higher than that of the corresponding halo acids Why

Answer 39

This is due to the zwitterionic nature of amino acids, which results in strong electrostatic and dipole-dipole interactions, as well as favorable interactions with water

Question 40

Where does the water present in the egg go after boiling the egg?

Answer 40

After boiling the egg, the water present in it is absorbed by the coagulated protein through H-bonding