Preparation of GLUCOSE?

Question

1.From sucrose
2.from starch

Answer 1

The enzyme invertase catalyzes the hydrolysis of the disaccharide sucrose to invert sugar. Invert sugar is a mixture of glucose and fructose, which are both monosaccharides.
http://www.geocities.com/CapeCanaveral/Hall/1410/lab-B-29.html
The hydrolysis of starch is done by amylases. With the aid of an amylase (such as pancreatic amylase), water molecules enter at the 1 -> 4 linkages, breaking the chain and eventually producing a mixture of glucose and maltose.
http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/C/Carbohydrates.html

Answer 2

Can be done by hydrolysis. Hydrolysis can be achieved by physical, chemical or biological (enzymatic) methods.

Sucrose is a disaccharide which consists of 1 molecule of glucose and fructose. Hydrolysis yields glucose and fructose mixture. The fructose can be fractionated and converted to glucose.
Starch is a homopolysaccharide of glucose, which can be subjected to hydrolysis to yield glucose molecules.

Answer 3

Either chemical hydrolysis or enzymatic of hydrolysis of either of those compounds will produce glucose.

Hydrolysis of sucrose will produce equal amounts of glucose and fructose. Hydrolysis of starch will produce just glucose.