Difference between Aldose and Ketose

Sugars having aldehyde groups are called Aldose and sugars with keto groups are called Ketose. The word ‘ode’ refers to sugar compounds. Both Aldose and Ketose are monosaccharides. 

Aldose is differentiated with the number of carbons at the main chain. Example, 

• Triose: glyceraldehyde 
• Tetrode: erythrose 
• Pentose: ribose, xylose, lyxose 
• Hexose: Glucose

Ketose contains only one ketone in a molecule. The simplest example of Ketose is dihydroxyacetone. It has three carbon atoms. Ketose is called the reducing sugar because of its epimerized property to convert into Aldose. Ketose is bounded with glycosidic bonds. 

Example

• Triose: Dihydroxyacetone
• Tetrose: erythrulose 
• Pentose: ribulose
• Hexose: fructose
• Heptose: sedoheptulose

Basic Difference

‘-ose’ at the final moment of a chemical phrase typically refers to a carbohydrate compound in chemistry. As a result, both aldoses, as well as ketoses, are chemical compounds that seem to be carbohydrates; to be more specific, they are ‘monosaccharides.’ Sugars could be made up of single repeating units or multiple repeating units. Sugars produced from single rephrasing are known as monosaccharides, while sugars made of two subunits are known as disaccharides. As a result, aldoses are monosaccharides with aldehyde groups at the carbon chain’s end, although ketoses are monosaccharides with ketone groups inside the carbon chain. This is the primary distinction between aldose and ketose. Both aldoses, as well as ketoses, are monosaccharides in general.

This is a monosaccharide with an aldehyde or ketone in its carbonyl group. In general, each monosaccharide molecule has one aldehyde group. The aldehyde or ketone is a chemically reactive group represented by the symbol (-CH=O). A molecule containing two atoms, one of which contains the aldehyde group, is the most basic form of the aldose. Cn (H2O)n is the chemical formula for aldose.

Ketose is a monosaccharide with a ketone group in its carbon skeleton. In general, one ketone group would exist for every sugar molecule. The ketone cohort is a chemically reactive group represented by the symbol (-C=O). The sugar molecule is the most basic form of ketose, consisting of three Carbon molecules, the middle one containing the ketone group. Ketones, like aldoses, have many stereogenic hubs inside the Carbon chain. Ketoses are also frequently depicted in their Fischer prediction. Seliwanoff’s test can distinguish ketoses from aldoses. The ketose interacts with the resorcinol to produce a profound cherry-red colour. Some well-known ketoses include fructose, ribulose, and erythrulose.

Ketose and Aldose can be differentiated chemically by a simple test called Seliwanoff’s test by heating the sample along with acid. Ketose quickly reacts with the solution and turned into dark red, while Aldose reacts in a slow manner and turns into pink. 

Aldose

Aldose is a type of monosaccharide which contains aldehydes on its carbon skeleton. Aldehydes are denoted as. (-CH=O). These can be divided into two subgroups, ie; 

1. D-aldose 
2. L-aldose 

Epimerism of Aldose

When sugars are different from one another, only in configuration with regard to a single carbon atom, other than the reference carbon atom, they are called the epimers. For example, glucose and mannose are an epimeric pairs which differ only with respect to C2. Similarly, galactose is the 4th epimer of glucose. 

Ketose

Ketose is a type of monosaccharide which contains a ketone group on the carbon skeleton. Ketones are denoted as (-C=O). The commonly known Ketoses are fructose, erythrulose, ribulose etc. 

Aldose and Ketose: Difference

1. Aldose is the monosaccharides which contain an aldehyde group on the carbon chain. Ketose is the monosaccharides which contain ketone groups on their carbon chain. 
2. In seliwanoff’s test Aldose reacts very slowly forming pink colour. Ketose reacts very quickly and forms a dark red colour in the solution. 
3. Aldose has the isometric property to form Ketose. Ketose can be isomerised when the carbonyl group is located at the end of the carbon chain. 
4. Aldose is an aldehyde group whereas Ketose belongs to the ketone group. 
5. Aldose is found in plants generally but ketones are found in processed food. 

Conclusion

Carbohydrates are the main sources of energy in the body. Molecules having one actual or potential sugar group are called monosaccharides. The Greek word mono means one and saccharide mean sugar. Both Aldose and Ketose are monosaccharide in nature. Depending on the number of carbon atoms the monosaccharides are named Triose(C3), Tetrose (C4), pentose(C5) etc. 

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