Carbohydrates are compounds that contain Carbon, Hydrogen and Oxygen. Carbohydrates are also known as saccharides and can be categorized into two different types, monosaccharides and polysaccharides.

n CO₂ + n H₂O + Energy –>(CH₂O)n + n O₂ 

Monosaccharides are known as Single Sugar are carbohydrates that cannot be hydrolyzed to simple carbohydrates. It has a chemical formula C₆H₁₂O₆. It can be divided into two forms Aldoses and Ketoses. Aldoses are carbohydrates that contains an aldehyde (Figure 1) and Ketoses are carbohydrates that contains a Ketone (Figure 2).

Fig. 1 Aldehyde Group (Science.uvu.edu,2015)

Fig 2 Ketone group (Science.uvu.edu, 2015)

Polysaccharides are high-molecular weight molecules that are formed by joining monosaccharides units together by glycosidic bonds. Polysaccharides can be divided into branched or unbranched homopolysaccharides and branched or unbranched heteropolysaccharides.                                                                                                            Unbranched homopolysaccharides are starch that have β(1,4)-linked glucose polymer. They are not branched and the chains are coiled. These chains are linked together by extensive hydrogen bondings. One of such polysaccharide is cellulose fibres found in cell walls.  Branched homopolysaccharides have α(1,4)-linked glucose polymer, periodically with a α(1,6)-linkage. α(1,4)-linked polymer forms a helix and consist of amylose and amylopectin.Starch can be digested by us which cellulose cannot be digested by us.

Video

Reference:

Benggang, X. (2014). CM1051 – Carbohydrates. Singapore.

http://science.uvu.edu/ochem/index.php/alphabetical/k-l/ketone/ [Accessed 18 Mar. 2015]

http://science.uvu.edu/ochem/index.php/alphabetical/a-b/aldehyde/ [Accessed 18 Mar. 2015]