AIIMS Chemistry Biomolecules Class 12 Questions

Assertion: Two sugar units joined by 1,2-glycosidic bond in sucralose. Reason: It contains 1 C-glucose and 2 C -fructose glycosidic bond

Assertion : Glucose does not gives 2,4-DNP test Reason : Glucose exists in cyclic hemiacetal form

Which is the chemical test for polysaccharide?

Select the correct set of answer:

Assume that a particular amino acid has an isoelectric point of $6.0$. In a solution of $\text{pH } 1.0$, which of the following species will predominate?

In the primary structure of proteins, the amino acids are interconnected by-

Amylopectin is

Assertion : The penta-acetate of glucose does not react with hydroxylamine. Reason : This is because free aldehyde group is not present in penta-acetate.

Glucose on reacting with benedict solution may give the following precipitates except

Which of the following linkage is found in sucrose?

Two aldopentoses A and B give the same osazone derivative. A is oxidised to an optically active aldoric acid by dilute nitric acid. Ruff degradation of B gave a tetrose which was similarly oxidised to an optically active aldaric acid. Assign the structure of A and B from the following list.

$2\text{ICl} \rightarrow \text{I}_2 + \text{Cl}_2 \quad K_c = 0.14$If initial concentration of $\text{ICl}$ is $0.6\text{ M}$, then equilibrium concentration of $\text{I}_2$ is:

Structure of Guanine is

Assertion : Boiling point of $\alpha\text{-D-glucose}$ is less than $\beta\text{-D-glucose}$. Reason : $\beta\text{-D-glucose}$ is more stable than $\alpha\text{-D-glucose}$.

Each of these questions contains two statements, Assertion (A) and Reason (R). Each of these questions also has four alternative choices, only one of which is the correct answer. You have to select one of the codes (a), (b), (c) and (d) given below. Assertion (A) A solution of sucrose in water is dextrorotatory while on hydrolysis in presence of little hydrochloric acid, becomes laevorotatory. Reason (R) Sucrose on hydrolysis give unequal amounts of glucose and fructose as result of which change in sign of rotation observed.

Assertion: Tyrosine behave as a acidic at pH = 7 Reason: pKₐ of phenol is mole than 7.

Assertion: A solution of sucrose in water is dextrorotatory but on hydrolysis in presence of little hydrochloric acid, it becomes laevorotatory. Reason: Sucrose on hydrolysis gives unequal amounts of glucose and fructose as a result of which change in sign of rotation is observed.

Assertion : Proteins are made up of $\alpha$-aminoacids. Reason : During denaturation, secondary and tertiary structures of proteins are destroyed.

The nitrogen base which is present in RNA and absent in DNA is

In the following questions a statement of Assertion (A) followed by a statement of Reason (R) is given. Choose the correct answer out of the following choice. Assertion (A) Glucose gives reddish brown precipitate with Fehling solution. Reason (R) Reaction of glucose with Fehling solution gives CuO and gluconic acid.

Glucose → HCN → Hydrolysis → HI, heat → A, A is

Among the following, the achiral amino acids is

Assertion: A solution of sucrose in water is dextrorotatory. But on hydrolysis in the presence of a little hydrochloric acid, it becomes laevorotatory. Reason: Sucrose on hydrolysis gives unequal amounts of glucose and fructose. As a result of this, change in sign of rotation is observed.

Assertion (A) A solution of sucrose in water is dextrorotatory while on hydrolysis in presence of little hydrochloric acid, it becomes laevorotatory. Reason (R) Sucrose on hydrolysis gives unequal amounts of glucose and fructose as a result of which change in sign of rotation is observed.

Which of the following is a non-reducing sugar?

Assertion: All enzymes are made up of proteins and all proteins have three dimensional structures. Reason: Secondary structures of protein are sequence of amino acids.

Which of the following is a homopolysaccharide?

Find the hydrolysis product when a phosphodiester bond of nucleotide breaks.

Find the hydrolysis product of maltose.

Assertion : β-pleated sheet structure of protein shows maximum extension.

The element which is the most abundant in the earth crust is

Assertion : Alpha (α)⁻amino acids exist as internal salt in solution as they have amino and carboxylic acid groups in near vicinity. Reason : H⁺ ion given by carboxylic group (–COOH) is captured by amino group (–NH₂) having lone pair of electrons.

The pair in which both species have iron is

Among the following L⁻serine is

Thymine is

Lysine is least soluble in water in the pH range

Methyl-α-D⁻glucoside and methyl-β-D⁻glucoside are

Which one of the following biomolecules is insoluble in water?

Which one of the following statements is true for protein synthesis (translation)?

Assertion : Maltose is a reducing sugar which gives two moles of D⁻glucose on hydrolysis. Reason : Maltose has a 1,⁴⁻β-glycosidic linkage.

The nucleic acid base having two possible binding sites is

Melting points are normally the highest for

Assertion : Sucrose is a non-reducing sugar. Reason : It has glycosidic linkage.

Subunits present in haemoglobin are

Among the following, the achiral amino acid is

Assertion : Haemoglobin is an oxygen carrier. Reason : Oxygen binds as O₂⁻ to Fe of haemoglobin.

Assertion : Glycosides are hydrolysed in acidic conditions. Reason : Glycosides are acetals.

Assertion : Activity of an enzyme is pH dependent. Reason : Change in pH affects the solubility of the enzyme in water.

Enzymes with two sites are called

Assertion : DNA molecules and RNA molecules are found in the nucleus of a cell. Reason : On heating, the enzymes do not lose their specific activity.