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A biomolecule is an organic molecule which results from biological process occurring within a

living organism. Of all molecules present in a living organism, four categories are

used to classify these.

Carbohydrates are compounds that contain large quantities of hydroxyl groups.

They may be of three types: monosaccharides which are also the monomer units 

[1] which are the building blocks of the other two types, disaccharides and

 polysaccharides.

Monosaccharides are the simplest of building blocks and is it impossible to

further hydrolyze it ( Nogrady and Weaver 2005) .Disaccharides are formed

upon the hydrolysis of two monosacarides. Oligsaccarides contain 3-10

monosaccharides and polysaccharides contain in excess of 10 of the monomer

units ( Nogrady and Weaver 2005) .

Carbohydrates are also classified into two major groups based on the functionalgroups present( Seager and Slabaugh 2011). If they contain an aldehyde group, -

CHO the compound is called a aldose or aldo sugar, where as if a ketone

group,C=O is present it is called a ketose or ketose sugar( Seager and Slabaugh

2011).

Sucrose is a disaccharide, thus it is formed upon the hydrolysis of two monomers,

which are: one molecule of glucose and one molecule of fructose (Kotz, Paul

,Treiche 2009).

The structure of sucrose (Kotz, Paul ,Treiche 2009).:

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A glycosidic bond is formed upon hydrolysis between the anomeric carbons( C1

on the glucose molecule and the C2 on the fructose molecule) resulting in the

formation of a non-reducing oligosaccharide(  Barnes,  Nelson,  Moore

and Collins 2007).

All monosaccharides and disaccharides are reducing sugars with the exception of

sucrose(Cheeke and Dierenfeld 2010).Reducing sugars possess a free aldehyde

group which can donate hydrogen. (Cheeke and Dierenfeld 2010).However,

sucrose does not possess a free aldehyde group so it is a non reducing sugar.

(Cheeke and Dierenfeld 2010).

There are various tests used to determine the presence and other characteristics of

carbohydrates.

Benedict’s test is used for identification of simple (reducing) sugars. The reagent

is an alkaline medium containing copper ions which are reduced by the free

aldehyde or ketone characteristic of simple sugars, to cuprous oxide, a reddish

 brown precipitate(Chawla 2003). 

Seliwanoff’s test caters to ketones and allows for its differentiation from aldoses

.It is characterized by a cherry red colored compound which results from the

reaction of the 5-hydromethyl furfural formed with resorcinol present in the

reagent(Chawla 2003). 

The acid catalyzed hydrolysis by HCl is of the A1 unimolecular reaction which

follows the protonation of the glycocidic oxygen followed by the heterolysis of

the resulting oxonium ion, to produce a monosaccharide molecule and a

carbenium ion (O’Brien 1998). The cabenium ion is then stabilized by

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substituents that contribute electrons. The ion then further reacts with water to

 produce a second molecule of monosaccharide (O’Brien 1998). 

The addition of a base NaOH functions to neutralize the solution and the resulting

monosaccharides of sucrose hydrolysis are D-glucose and D-fructose ( Rauter and

Rauter2010). Elevated temperatures are also required in addition to the acid toenable this breakdown reaction ( Rauter and Rauter2010).

The acid catalysed hydrolysis of sucrose ( Rauter and Rauter 2010):

Vitamins Methionine SIC (absorbic acid ) is one of the most important vitamins

required by humans (Combs Jr.2012). It has many important roles in the body,

among those is it antioxidant property which enables the protection of cells and

 prevents as the name implies oxidation (Combs Jr.2012).

It is also utilized in the area of food technology to act as a stabilizer for the

 processing of a range of beverages and wines (Ball 1998).

The acid is unstable, of highly reducing and under goes oxidation easily.It is alsovery soluble in water (Joshi 2010).

Structure of L-ascorbic acid, monodehydroascorbate and DHA

(Salter, Wiseman, and Tucker 2012):

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Absorbic acid with its reducing property reduces dichlorophennol-indophenol

solution (DCPIP),a redox dye, to its colorless leuco-dye form and appears pale

 pink in an acid solution (Mohan 2007).

Reaction mechanism for DCPIP( McCormick 1985):