Question

Question:-
a) what are carbohydrates? define polysaccharides. write two functions of carbohydrates.

b) what are disaccharides? write the ring structure of sucrose.​

Answer 1

Answer:

a)

Carbohydrates:- Carbohydrates are naturally occurring sugars, starches and fiber in food. All carbohydrates are made up of sugar molecules. Sugar molecules linked together form starches and fiber. In the body, starches and sugars are broken down in the digestive system to glucose.

Polysaccharides:- A carbohydrate (e.g. starch, cellulose, or glycogen) whose molecules consist of a number of sugar molecules bonded together

Functions of Carbohydrates

• Providing energy and regulation of blood glucose.
• Sparing the use of proteins for energy.
• Breakdown of fatty acids and preventing ketosis.

b)

Dsaccharide:- A disaccharide is the sugar formed when two monosaccharides are joined by glycosidic linkage. Like monosaccharides, disaccharides are soluble in water. Three common examples are sucrose, lactose, and maltose. Disaccharides are one of the four chemical groupings of carbohydrates.

Ring structure of sucrose:- Sucrose is a molecule composed of two monosaccharides, namely glucose and fructose. This non-reducing disaccharide has a chemical formula of C12H22O11. ... This type of linking of two monosaccharides called glycosidic linkage. Sucrose has a monoclinic crystal structure and is quite soluble in water.Oct 4, 2020

Chemical Formula of Sucrose: C12H22O11

Molar Mass or Molecular Weight: 342.30 g/mol

Explanation:

Hope it helps You...........

Answer 2

(a) Carbohydrate:- the word carbohydrate was originally used to describe glucose, " a hydrate of carbon $\large\rm { C_{6} ( H_{2} O)_{6}}$ ". but now carbohydrates are defined as polyhydroxylated aldehydes or ketones or the substances which produce these substances on hydrolysis.

Polysaccharides are compounds such as cellulose and starch that are made up of many simple sugars linked together. on hydrolysis, these are broken to produce many molecules of simple sugars.

Functions of carbohydrates:-

(i) Many carbohydrates form part of the coating around all living cells.

(ii) they act as fuel to provide energy to keep the organism running. on hydrolysis, polysaccharides are broken to produce glucose which is transported from cell to cell by the blood and its oxidation provides energy for the functioning of the organism.

$\large\rm { C_{6} H_{12} O_{6} + 6 O_{2} \longrightarrow 6CO_{2} + 6 H_{2} O + 2832 kJ}$

(iii) some carbohydrates are found in the DNA that carries genetic information from one generation to next.

Answer for (b) part:-

A disaccharide is a sugar, one molecule of which , on hydrolysis , gives two monosaccharide molecules, which may be identical or different. the three most important disaccharides are sucrose ( cane-sugar) , lactose ( milk-sugar) , maltose ( malt-sugar).

Ring structure of sucrose has six-membered α D-Glucopyranose ring combined with five membered β-D-Fructofuranose ring.