Write two main functions of carbohydrates in plants.
Solution and Explanation
Two main functions of carbohydrates in plants are:
(i) Polysaccharides such as starch serve as storage molecules.
(ii) Cellulose, a polysaccharide, is used to build the cell wall
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Write IUPAC names of the following compounds and classify them into primary, secondary and tertiary amines.
(i) (CH3 )2CHNH2 (ii) CH3 (CH2 )2NH2 (iii) CH3NHCH(CH3 )2
(iv) (CH3 )3CNH2 (v) C6H5NHCH3 (vi) (CH3CH2 )2NCH3 (vii) m–BrC6H4NH2
Give one chemical test to distinguish between the following pairs of compounds.
(i) Methylamine and dimethylamine
(ii) Secondary and tertiary amines
(iii) Ethylamine and aniline
(iv) Aniline and benzylamine
(v) Aniline and N-methylanilineAccount for the following:
(i) pKb of aniline is more than that of methylamine.
(ii) Ethylamine is soluble in water whereas aniline is not.
(iii) Methylamine in water reacts with ferric chloride to precipitate hydrated ferric oxide.
(iv) Although amino group is o– and p– directing in aromatic electrophilic substitution reactions, aniline on nitration gives a substantial amount of m-nitroaniline.
(v) Aniline does not undergo Friedel-Crafts reaction.
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Concepts Used:
Carbohydrates
Carbohydrates, or carbs, are sugar molecules. Along with proteins and fats, carbohydrates are one of three main nutrients found in foods and drinks.
Your body breaks down carbohydrates into glucose. Glucose, or blood sugar, is the main source of energy for your body's cells, tissues, and organs. Glucose can be used immediately or stored in the liver and muscles for later use.
Classification of Carbohydrates
Carbohydrates are divided into two categories: simple and complex, based on their chemical structure and degree of polymerization.
Simple Carbohydrates (Monosaccharides, Disaccharides and Oligosaccharides)
One or two sugar molecules make up simple carbohydrates. Simple carbohydrates cause blood sugar levels to rise because molecules are easily digested and converted. Milk products, alcohol, vegetables, processed sugars, candies, and other foods contain a lot of them. These carbohydrates are referred to as "empty calories" because they lack fibre, vitamins, and minerals.
Complex Carbohydrates (Polysaccharides)
Starchy foods contain two or more sugar molecules and are thus referred to as complex carbohydrates. In comparison to simple carbohydrates, molecules in complex carbohydrates are digested and converted slowly. They are found in large quantities in potatoes, corn, cereals, lentils, peanuts, beans, whole-grain bread, peas, etc.
Carbohydrates can be found in the following examples:
- Glucose
- Galactose
- Maltose
- Fructose
- Sucrose
- Lactose
- Starch
- Cellulose
- Chitin