Aldose and ketose are monosaccharides. Monosaccharides are simple sugars with an unbranched carbon chain as the backbone. Examples of monosaccharides are glucose, fructose, or deoxyribose. Most monosaccharides have either an aldehyde group or a ketose group.
An aldose sugar contains an aldehyde group per molecule. If it contains more than 3 carbon atoms, it can be isomerized into ketoses. It is primarily found in plant-based food, and it appears as light pink under Selwanoff’s test. Examples of aldose sugar include Glucose, galactose, and ribose.
A ketose sugar contains a ketone group in its carbon skeleton. It is important to note that only in the presence of a reducing sugar will a ketose be isomerized to aldose. Ketone sugar appears as dark cherry red on Seliwanoff’s test. Ketose is found in processed food. Fructose, ribulose, and erythrulose all have ketose.
The aldose group only has one carbon atom within the aldehyde group. The aldose molecules also have five other hydroxyl groups. The majority of the aldehyde group is cyclic in structure. Usually, when molecules have cyclic structures, they form a six-member ring structure called a hemiacetal ring because of the presence of carbon.
On the other hand, a ketose is sugar with one ketone group for every molecule. An example of one from a ketone group is hexoses, and an example of hexoses is fructose. Sources of fructose include fruit juice, agave, and other fruits such as raisins and prunes.
Honey and molasses also contain an effective dose of fructose. Aldose is a monosaccharide with an aldehyde group, and aldose may be distinguished from ketoses. Aldoses are generally found in plants. An example of aldose is glucose. Glucose may be found in individual grains, fruits, and vegetables.
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Answered Apr 21, 2020
The aldose molecules have five hydroxyl groups. The majority of aldose molecules usually has a cyclic structure. Often, when the molecules of a hydrocarbon have a cyclic structure, they would form a six-member ring structure, which is called a hemiacetal ring because of the presence of carbon. Ketose, on the other hand, is a sugar which has one ketone group for each of its molecule.
Some examples of Ketose include pentoses, hexoses, across, trioses, tetroses, heptoses, etc. Hexoses can also be referred to as ketoses if their group includes sorbose, fructose, psicose, and tagatose. Some of the rich sources of fructose include fruits such as agave.
Some other sources of fructose include dates, raisins, prunes, figs, etc. Even honey and molasses do contain a high dose of fructose. Some processed foods such as ketchup, barbecue sauce, salad dressings, and cereals, sweet-and-sour sauces, etc. are also a high source of fructose.
The Aldose contains an aldehyde group, and ketose contains a ketone group. A great way to the remember this difference is to focus on the first letter in each term: 'a' is for aldehyde in Aldose, 'k' is for ketone in the etose. Another difference is location of the carbonyl group in each structure.