Which one of the following is a disaccharide : strach, Maltose, Fructose, Glucose ?

1

(a)

Maltose is a disaccgaride since it consists of two \(\alpha\)-glucose units.

What are tetrasaccharides ? Give an example.

1

(a)

Tetrasaccharides on hydrolysis give four molecules of the same or different monosaccharides. For example stachyrose on hydrolysis gives one molecule of glucose, one molecule of frutose and two molecules of galactose.

What are polysaccharides ? Give one example.

1

(a)

Polysaccharides on hydrolysis give a large number of molecules of monosaccharides. For example, starch or cellulose.

Name one reducing and one-non reducing disaccharide .

1

(a)

Maltose or lactose (reducing); sucrose (non-reducing).

What is mutarotation?

1

(a)

The spontaneous chage of specific rotation of an optically active substance with time is called mutarotation. For example, when a freshly prepared solution of \(\alpha\) -glucose is allowed to stand. Its specific rotation decreases from +111^o to + 52.5^o with time and that of \(\beta\)-D-glucose increases from + 19.2^o to + 52.5^o.