Question

Stachyose is a.
(A) Mnosaccharide
(B) Disaccharide
(C) Trisaccharide
(D) Tetrasaccharide

Answer 1

Hint: Stachyose is carbohydrate and consists of monosaccharide units. Its molecular formula is ${C_{24}}{H_{42}}{O_{11}}$carbohydrates are sugar, starches and fibers found in fruits, vegetables and milk products.


Step by step answer: Carbohydrate classified on the basis of number of monosaccharide units present. They are Oligosaccharides: They contain two to ten monosaccharides etc.
Polysaccharides: They contain a large number of monosaccharide units.
Slachyose is included in oligosaccharides because it contains four monosaccharide units.
It consists of two $\alpha - D - $galactose units, one $\alpha - D - $glucose unit and one $\beta - D - $fructose unit.
These monosaccharide units are linked together through glycosidic bonds.
Its IUPAC name is alpha-D-galactose $(1 > 6)$$\alpha $\[\; - D\]\[\; - \]galactose moiety attached at 6-position of glucose.
The units of stachyose are linked as galgalgl cfru.
gal$ \to $means galactose glu$ \to $means glucose fru$ \to $means fructose.

Therefore, from the above explanation the correct option is (D) Tetrasaccharide.

Additional Information: Stachyose occurs naturally in many vegetables and other plants.
Stachyose are non-reducing sugar.
Non-reducing sugar does not reduce Fehling’s solution and Tollens reagent.
The linkage in stachyose is as follows:
$gal(\alpha 1 \to 6)gal(\alpha 1 \to 6)glc(\alpha 1 \to 2\beta )Fru$
Stachyose also known as stachyose hydrate.
This is a very weakly acidic compound. It has been found in human prostate tissue
Stachyose is involved in a metabolic disorder called galactosemia pathway.


Note: Stachyose onycholysis its monosaccharide unit such far as $2,\alpha - D - $galactose, one $\alpha - D - $glucose and one fructose unit.
It shows that stachyose is tetrasaccharides.