Class 12th
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New answer posted
11 months agoContributor-Level 10
14.27
Vitamins can be defined as the essential dietary factors required by an organism in minute quantities and whose absence causes specific deficiency Vitamins are broadly classified into two types:-
(i) Fat-soluble vitamins:
These are oily substances not readily soluble in water. These include vitamins A, D, E and K. Vitamin K is responsible for the coagulation of blood.
(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.
Vitamin H (Biotin) as an exception, it is neither soluble in water nor in fat
New answer posted
11 months agoContributor-Level 10
14.26
During denaturation, 2-degree and 3-degree structures of proteins are destroyed but 1- degree structure remains intact. As a result of denaturation, The globular proteins (soluble in water) are converted into Fibrous proteins (insoluble in water) and their biological activity is lost. For example, boiled egg which contains coagulated proteins cannot be hatched to produce chickens.
New answer posted
11 months agoContributor-Level 10
These compounds give different ions in aqueous solution. This can be tested by using AgNO3 solution and BaCl2
[Co (NH3)5Cl]SO4 (aq) + BaCl2 (aq) → BaSO4 (ppt)
[Co (NH3)5Cl]SO4 (aq) + AgNO3 (aq) → no reaction
[Co (NH3)5 (SO4)]Cl (aq) + BaCl2 (aq) → no reaction
[Co (NH3)5 (SO4)]Cl (aq) + AgNO3 (aq) → AgCl (ppt)
Hence, they give different precipitates with different solutions. Thus, they are ionisation isomers.
New answer posted
11 months agoContributor-Level 10
14.25
Enzymes are naturally occurring simple conjugate proteins acting as specific catalysts in all processes. In contrast to ordinary chemical catalyst, it loses activity by pH or temperature change.
For example:- the enzyme used to catalyze the hydrolysis of maltose into glucose is named as maltase.
Enzymes are highly specific, i.e., a particular enzyme catalyses a specific reaction. For example, urase attacks on urea. This specific action is due to active sites present in the enzyme molecule (E) that fits into substrate (S) and forms E-S complex which changes into product P and E.
Enzymes increase the speed of reactions. They can cataly
New answer posted
11 months agoContributor-Level 10
(i) K [Cr (H2O)2 (C2O4)2 exhibits geometrical isomerism (Cis and trans) and optical isomerism of cis and trans
(ii) Optical isomerism exhibiting mirror
(iii) Ionisation isomerism- [Co (NH3)5 (NO3)] (NO3) (NO2) and Linkage isomerism- [Co (NH3)5 (ONO)] (NO3)2
(iv) Geometrical isomers are seen in [Pt (NH3) (H2O)Cl2]
New answer posted
11 months agoContributor-Level 10
(i) Hexaminecobalt (III)chloride
(ii) Pentaaminechloridecobalt (III)chloride
(iii) Potassium hexacyanoferrate (III)
(iv) Potassium trioxalatoferrate (III)
(v) Potassium tetrachloridopalladate (II)
(vi) Diaminechloride (methylamine)platinum (II)chloride
New answer posted
11 months agoContributor-Level 10
14.24
Amino acids contain an acidic (carboxyl group) and a basic (amino) group within the same molecule. In aqueous solution, they neutralize each other. The carboxyl group loses a proton while the amino group accepts it. S a result, a dipolar or zwitter-ion is formed.
In zwitter ionic form, the amino acid show amphoteric behaviour as they react with both acids and bases. In the acidic medium, COO- ion of the zwitter-ion accepts a proton to form the cation first, while in the basic medium, +NH3 ion loses a proton to form the anion, as shown below:-
New answer posted
11 months agoContributor-Level 10
(i) [Co (NH3)4 (H2O)2]Cl3
(ii) K2 [Ni (CN)4]
(iii) [Pt (en)3]NO3
(iv) [Pt (NH3)BrCl (NO2)]
(v) [Pt (Cl)2 (en)2] (NO3)2
(vi) Fe4 [Fe (CN)6]3
New answer posted
11 months agoContributor-Level 10
14.23
Globular proteins | Fibrous proteins |
It is usually soluble in water. | It is insoluble in water. |
All enzymes are globular protein. Some hormones such as insulin are also globular protein. | Fibrous proteins are usually used for structural purposes. For example, keratin is present in nails and hair; collagen in tendons; and myosin in muscles. |
The polypeptide chain in this protein is folded around itself, giving rise to spherical structure. | It is a fibre-like-structure formed by the polypeptide chain. These proteins are held together by strong and disulphide bonds. |
They are soluble in acids and bases. | They are insoluble in acids and bases. |
Examples:- egg albumin, casein of milk. | Examples :- Silk, Skin, Wool. |
They have weak intermolecular hydrogen bonding. | They have comparatively stronger intermolecular forces of attraction. |
They have folded, ball like structure. | They have thread like structure. |
Globular proteins are also called as spheroproteins owing to their shape. | Fibrous proteins are also called as scleroproteins. |
More sensitive to the changes in pH, temperature etc. | Less sensitive to the changes in pH, temperature etc. |
New answer posted
11 months agoContributor-Level 10
14.22
The stability of α-helix structure is due to intramolecular hydrogen bonding between –NH and –CO groups of polypeptide chain. The α-helix is known as 3.613 because each turn of α-helix contains approximately 3.6 amino acids and a 13-membered ring is formed by hydrogen bonding.
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