Write the names of monomers of the following polymers:
Question: Write the names of monomers of the following polymers: Solution: (i) Hexamethylenediamine $\left[\mathrm{H}_{2} \mathrm{~N}-\left(\mathrm{CH}_{2}\right)_{6}-\mathrm{NH}_{2}\right]$ and adipic acid $\left[\mathrm{HOOC}-\left(\mathrm{CH}_{2}\right)_{4}-\mathrm{COOH}\right]$ (ii) (iii) Tetrafluoroethene $\left(\mathrm{CF}_{2}=\mathrm{CF}_{2}\right)$...
Read More →Classify the following as addition and condensation polymers:
Question: Classify the following as addition and condensation polymers: Terylene, Bakelite, Polyvinyl chloride, Polythene. Solution: Addition polymers: Polyvinyl chloride, polythene Condensation polymers: Terylene, bakelite...
Read More →How are polymers classified on the basis of structure?
Question: How are polymers classified on the basis of structure? Solution: Polymers are classified on the basis of structure as follows: 1. Linear polymers: These polymers are formed of long straight chains. They can be depicted as: For e.g., high density polythene (HDP), polyvinyl chloride, etc. 2. Branched chain polymers: These polymers are basically linear chain polymers with some branches. These polymers are represented as: For e.g., low density polythene (LDP), amylopectin, etc. 3. Cross-li...
Read More →What are polymers?
Question: What are polymers? Solution: Polymers are high molecular mass macromolecules, which consist of repeating structural units derived from monomers. Polymers have a high molecular mass (103 107u). In a polymer, various monomer units are joined by strong covalent bonds. These polymers can be natural as well as synthetic. Polythene, rubber, and nylon 6, 6 are examples of polymers....
Read More →What are the different types of RNA found in the cell?
Question: What are the different types of RNA found in the cell? Solution: (i)Messenger RNA (m-RNA) (ii)Ribosomal RNA (r-RNA) (iii) Transfer RNA (t-RNA)...
Read More →Write the important structural and functional differences between DNA and RNA.
Question: Write the important structural and functional differences between DNA and RNA. Solution: The structural differences between DNA and RNA are as follows: The functional differences between DNA and RNA are as follows:...
Read More →The two strands in DNA are not identical but are complementary.
Question: The two strands in DNA are not identical but are complementary. Explain. Solution: In the helical structure of DNA, the two strands are held together by hydrogen bonds between specific pairs of bases. Cytosine forms hydrogen bond with guanine, while adenine forms hydrogen bond with thymine. As a result, the two strands are complementary to each other....
Read More →What is the difference between a nucleoside and a nucleotide?
Question: What is the difference between a nucleoside and a nucleotide? Solution: A nucleoside is formed by the attachment of a base to1'position of sugar. Nucleoside = Sugar + Base On the other hand, all the three basic components of nucleic acids (i.e., pentose sugar, phosphoric acid, and base) are present in a nucleotide. Nucleotide = Sugar + Base + Phosphoric acid...
Read More →What are nucleic acids?
Question: What are nucleic acids? Mention their two important functions. Solution: Nucleic acids are biomolecules found in the nuclei of all living cells, as one of the constituents of chromosomes. There are mainly two types of nucleic acids deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). Nucleic acids are also known as polynucleotides as they are long-chain polymers of nucleotides. Two main functions of nucleic acids are: (i)DNA is responsible for the transmission of inherent characters...
Read More →Why are vitamin A and vitamin C essential to us?
Question: Why are vitamin A and vitamin C essential to us? Give their important sources. Solution: The deficiency of vitamin A leads to xerophthalmia (hardening of the cornea of the eye) and night blindness. The deficiency of vitamin C leads to scurvy (bleeding gums). The sources of vitamin A are fish liver oil, carrots, butter, and milk. The sources of vitamin C are citrus fruits,amla, and green leafy vegetables....
Read More →How are vitamins classified?
Question: How are vitamins classified? Name the vitamin responsible for thecoagulation of blood. Solution: On the basis of their solubility in water or fat, vitamins are classified into two groups. (i)Fat-soluble vitamins:Vitamins that are soluble in fat and oils, but not in water, belong to this group. For example: Vitamins A, D, E, and K (ii)Water-soluble vitamins:Vitamins that are soluble in water belong to this group. For example: B group vitamins (B1, B2, B6, B12, etc.) and vitamin C Howeve...
Read More →What is the effect of denaturation on the structure of proteins?
Question: What is the effect ofdenaturation on the structure of proteins? Solution: As a result ofdenaturation, globules get unfolded and helixes get uncoiled. Secondary and tertiary structures of protein are destroyed, but the primary structures remain unaltered. It can be said that during denaturation, secondary and tertiary-structured proteins get converted into primary-structured proteins. Also, as the secondary and tertiary structures of a protein are destroyed, the enzyme loses its activit...
Read More →What are enzymes?
Question: What are enzymes? Solution: Enzymes are proteins that catalyse biological reactions. They are very specific in nature and catalyse only a particular reaction for a particular substrate. Enzymes are usually named after the particular substrate or class of substrate and some times after the particular reaction. For example, the enzyme used to catalyse the hydrolysis of maltose into glucose is named as maltase. Again, the enzymes used to catalyse the oxidation of one substrate with the si...
Read More →How do you explain the amphoteric behaviour of amino acids?
Question: How do you explain the amphoteric behaviour of amino acids? Solution: In aqueous solution, the carboxyl group ofan amino acid can lose a proton and the amino group can accept a proton to give a dipolar ion known as zwitter ion. Therefore, in zwitter ionic form, the amino acid can act both as an acid and as a base. Thus, amino acids show amphoteric behaviour....
Read More →Differentiate between globular and fibrous proteins.
Question: Differentiate between globular and fibrous proteins. Solution:...
Read More →What type of bonding helps in stabilising the ∝-helix structure of proteins?
Question: What type of bonding helps in stabilising the-helix structure of proteins? Solution: The H-bonds formed between the NH group of each amino acid residue and thegroup of the adjacent turns of the-helix help in stabilising the helix....
Read More →What are the common types of secondary structure of proteins?
Question: What are the common types of secondary structure of proteins? Solution: There are two common types of secondary structure of proteins: (i)-helix structure (ii)-pleated sheet structure - Helix structure: In this structure, the NH group ofan amino acid residue forms H-bond with thegroup of the adjacent turn of the right-handed screw (-helix). -pleated sheet structure: This structure is called so because it looks like the pleated folds of drapery. In this structure, all the peptide chains...
Read More →What are the common types of secondary structure of proteins?
Question: What are the common types of secondary structure of proteins? Solution: There are two common types of secondary structure of proteins: (i)-helix structure (ii)-pleated sheet structure - Helix structure: In this structure, the NH group ofan amino acid residue forms H-bond with thegroup of the adjacent turn of the right-handed screw (-helix). -pleated sheet structure: This structure is called so because it looks like the pleated folds of drapery. In this structure, all the peptide chains...
Read More →The interior of a building is in the form of a cylinder of base radius 12 m
Question: The interior of a building is in the form of a cylinder of base radius 12 m and height 3.5 m, surmounted by a cone of equal base and slant height 12.5 m. Find the internal curved surface area and the capacity of the building. Solution: Height of the cone Capacity (volume) of cone Capacity (volume) of cylinder Therefore, Total capacity of building Internal curved surface area of the building...
Read More →Define the following as related to proteins
Question: Define the following as related to proteins (i)Peptide linkage(ii)Primary structure(iii)Denaturation. Solution: (i) Peptide linkage: The amide formed between COOH group of one molecule of an amino acid and NH2group of another molecule of the amino acid by the elimination of a water molecule is called a peptide linkage. (ii) Primary structure: The primary structure of protein refers to thespecific sequence in which various amino acids are present in it, i.e., the sequence of linkages be...
Read More →An iron pole consisting of a cylindrical portion 110 cm
Question: An iron pole consisting of a cylindrical portion 110 cm high and of base diameter 12 cm is surmounted by a cone 9 cm high. Find the mass of the pole, given that 1 cm3of iron has 8 gram mass approximately.(Use : = 355/115) Solution: Volume of cylinder Volume of cone Therefore, Therefore, Mass of the pole...
Read More →What are essential and non-essential amino acids?
Question: What are essential and non-essential amino acids? Give two examples ofeach type. Solution: Essential amino acids are required by the human body, but they cannot be synthesised in the body. They must be taken through food. For example: valine and leucine Non-essential amino acids are alsorequired by the human body, but they can be synthesised in the body. For example: glycine, and alanine...
Read More →Enumerate the reactions of
Question: Enumerate the reactions of D-glucose which cannot be explained by its open chain structure. Solution: (1)Aldehydes give 2, 4-DNP test, Schiffs test, and react with NaHSO4to form the hydrogen sulphite addition product. However, glucose does not undergo these reactions. (2)The pentaacetate of glucose does not react with hydroxylamine. This indicates that a free CHO group is absent from glucose. (3)Glucose exists in two crystalline forms and. The-form (m.p. = 419 K) crystallises from a co...
Read More →A tent of height 8.25 m is in the form of a right circular cylinder
Question: A tent of height 8.25 m is in the form of a right circular cylinder with diameter of base 30 m and height 5.5 m, surmounted by a right circular cone of the same base. Find the cost of the canvas of the tent at the rate of Rs 45 per m2. Solution: $l=\sqrt{(2.75)^{2}}+(15)^{2}$ $l=\sqrt{232.5625}$ $=15.25$ Total surface area of the tent $=2 \pi r h+\pi r l$ $=\pi r(2 h+l)$ $=\frac{22}{7} \times 15[2 \times 5-5+15.25]$ $=\frac{330 \times 26.25}{7}$ $=1237.5$ Therefore, Cost of the canvas ...
Read More →What happens when D-glucose is treated with the following reagents?
Question: What happens when D-glucose is treated with the following reagents? (i)HI(ii)Bromine water(iii)HNO3 Solution: (i)When D-glucose is heated with HI for a long time, n-hexane is formed. (ii)When D-glucose is treated with Br2water, D- gluconic acid is produced. (iii)On being treated with HNO3, D-glucose get oxidised to give saccharic acid....
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