Class 12th

This is a Assertion and Reason Type Questions as classified in NCERT Exemplar

Ans: (a)

In Hoffmann bromamide degradation reaction as in this reaction primary amide group is treated with halogen first bromine then the halogen substituted amide product is coverts to primary amine with the release of carbon dioxide gas. Both the statements assertion and reason are incorrect therefore the correct option is a. 

This is a Short Answer Type Questions as classified in NCERT Exemplar

Nucleosides are linked to phosphoric acid at the 5′ position of the sugar moiety to produce a nucleotide. Furthermore, phosphodiester linkage between the 5′ and 3′ carbon atoms of pentose sugar bonds nucleotides (two molecules) together to generate dinucleotide. Phosphoric acid aids in the formation of this connection.

This is a Assertion and Reason Type Questions as classified in NCERT Exemplar

Ans: (c)

In the acryl derivative, the delocalisation of electrons of the nitrogen atom occur over the carbonyl group, this decreases the electron density on the nitrogen atom that it no more perform as nucleophile and don't react with next acylating alkaline molecule. 

Therefore, Assertion statement is correct but reason is incorrect.

This is a Short Answer Type Questions as classified in NCERT Exemplar

Glucose reacts with hydroxylamine to form a monoxime, which is then combined with one molecule of hydrogen cyanide to form cyanohydrin. The reactions are shown in the table below.

It has a carbonyl group as a consequence, which can be an aldehyde or a ketone. Gluconic acid, a carboxylic acid containing six carbon atoms, is formed when glucose is gently oxidised with bromine water.

This is a Matching Type Questions as classified in NCERT Exemplar

 Ans: (i)- (b), (ii)- (a), (iii)- (d), (iv)- (c)

This is a Short Answer Type Questions as classified in NCERT Exemplar

Biocatalysts are enzymes that act as catalysts in biological reactions. They reduce the size of activation energy by finding a suitable path. Because the enzyme sucrase reduces the activation energy of sucrose hydrolysis from to, enzyme-catalyzed reactions occur at a much faster rate than traditionally catalysed ones. 

This is a Short Answer Type Questions as classified in NCERT Exemplar

Physical or chemical changes damage hydrogen bonding and other attractive factors. In addition, globules uncoil and the helix uncoils, resulting in a thread-like molecule. As a result, the biological activity of protein secondary and tertiary structures is lost entirely or partially. Protein denaturation is the term for this.

This is a Matching Type Questions as classified in NCERT Exemplar

Ans: (i)- (d), (ii)- (c), (iii)- (a), (iv)- (b)

This is a Short Answer Type Questions as classified in NCERT Exemplar

Since both acidic (−COOH) and basic (−NH₂) groups present in amino acids, it act like salts rather than simple amines or carboxylic acids. In Ans, a −COOH a group can release a proton and an amine group can take a proton, resulting in the formation of a dipolar ion known as zwitterion.

This is a Short Type Questions as classified in NCERT Exemplar

Ans: