Chemistry

Biomolecules

Question:

What are the expected products of hydrolysis of lactose?

Answer:

Lactose being a disaccharide gives two molecules of monosaccharides Le. one molecule each of D-(+) – glucose and D-(+)-galactbse.
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Biomolecules

Q 1.

The letters ' D ' or ' L' before the name of a stereoisomer of a compound indicate the correlation of configuration of that particular stereoisomer.
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This refers to their relation with one of the isomers of glyceraldehydes. Predict whether the following compound has ‘D' or ‘L' configuration.

Q 2.

During curdling of milk, what happens to sugar present in it?

Q 3.

What are essential and non-essential amino acids? Give two examples of each type.

Q 4.

Which monosaccharide units are present in starch, cellulose and glycogen and which linkages link these units?

Q 5.

Which of the following terms are correct about enzyme?
(a) Proteins (b) Dinucleotides
(c) Nucleic acids (d) Biocatalysts

Q 6.

Describe the term D- and L-configuration used for amino acids with examples.

Q 7.

Assertion (A): Vitamin D can be stored in our body.
Reason (R): Vitamin D is fat soluble vitamin.

Q 8.

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

Q 9.

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?

Q 10.

Assertion (A): Deoxyribose, C5H10O4 is not a carbohydrate.
Reason (R): Carbohydrates are hydrates of carbon so compounds which follow Cx(H2O)y formula are carbohydrates.

Q 11.

Name the linkage connecting monosaccharide units in polysaccharides.

Q 12.

Sucrose is dextrorotatory but the mixture obtained after hydrolysis is laevorotatory. Explain.

Q 13.

What are the common types of secondary structure of proteins?

Q 14.

Why does compound (A) given below not form an oxime?
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Q 15.

Why are vitamin A and vitamin C essential to us? Give their important sources.

Q 16.

Why must vitamin C be supplied regularly in diet?

Q 17.

What is glycogen? How is it different from starch?

Q 18.

What is the difference between a nucleoside and a nucleotide?

Q 19.

Carbohydrates are classified on the basis of their behaviour on hydrolysis and also as reducing or non-reducing sugar. Sucrose is a .
(a) monosaccharide (b) disaccharide
(c) reducing sugar (d) non-reducing sugar

Q 20.

How do you explain the presence of all six carbon atoms in glucose in a straight chain?

Q 21.

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Q 22.

α-Helix is a secondary structure of proteins formed by twisting of polypeptide chain into right handed screw like structures. Which type of interactions are responsible for making the a-helix structure stable?

Q 23.

Match the vitamins given in Column I with the deficiency disease they cause given in Column II.
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Q 24.

What are enzymes?

Q 25.

Assertion (A): All naturally occurring a-amino acids except glycine are optically active.
Reason (R): Most naturally occurring amino acids have L-configuration.

Q 26.

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Q 27.

Aldopentoses named ribose and 2-deoxyribose are found in nucleic acids.
What is their relative configuration?

Q 28.

How do enzymes help a substrate to be attacked by the reagent effectively?

Q 29.

Differentiate between globular and fibrous proteins.

Q 30.

What is the effect of denaturation on the structure of proteins?

Q 31.

What are nucleic acids ? Mention their two important functions.

Q 32.

Three structures are given below in which two glucose units are linked. Which of these linkages between glucose units are between C1 and C4 and which linkages are between C1 and C6?
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Q 33.

Monosaccharides contain carbonyl group hence are classified, as aldose or ketose. The number of carbon atoms present in the monosaccharide molecule are also considered for classification. In which class of monosaccharide will you place fructose?  

Q 34.

How do you explain the presence of five -OH groups in glucose molecule?

Q 35.

Amino acids behave like salts rather than simple amines or carboxylic acids. Explain.

Q 36.

Match the following enzyme given in Column I with the reactions they catalyse given in Column II.
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Q 37.

What are monosaccharides ?

Q 38.

Which of the following monosaccharides are present as five membered cyclic structure (foranose structure)?
(a) Ribose (b) Glucose (c) Fructose (d) Galactose

Q 39.

Some enzymes are named after the reaction, where they are used. What name is given to the class of enzymes which catalyse the oxidation of one substrate with simultaneous reduction of another substrate?

Q 40.

Structures of glycine and alanine are given below. Show the peptide linkage in glycylalanine.
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Q 41.

Activation energy for the acid catalysed hydrolysis of sucrose is 6.22 kJ mol-1, while hydrolysis is catalysed by the enzyme sucrase. Explain.

Q 42.

Assertion (A): Glycine must’be taken through diet.
Reason (R): It is an essential amino acid.

Q 43.

Why cannot Vitamin C be stored in our body?

Q 44.

What type of bonding helps in stabilising the α-helix structure of proteins?

Q 45.

Under what conditions glucose is converted to gluconic and saccharic acid?

Q 46.

Assertion (A): β-glycosidic linkage is present in maltose.
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Reason (R): Maltose is composed of two glucose units in which C-l of one glucose unit is linked to C-4 of another glucose unit.

Q 47.

Carbohydrates are essential for life in both plants and animals. Name the carbohydrates that are used as storage molecules in plants and animals, also name the carbohydrate which is present in wood or in the fibre of cotton cloth.

Q 48.

What are the expected products of hydrolysis of lactose?

Q 49.

What do you understand by the term glycosidic linkage?

Q 50.

Three cyclic structures of monosaccharides are given below which of these are anomers.
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