Carbohydrates are the most abundant class of biomolecules in nature. A carbohydrate is composed of carbon, hydrogen and oxygen with a general formula (CH2O)n where ‘n’ is 3 or more (n= no. of C atom).Chemically carbohydrates are poly hydroxyl aldehydes or ketones and their derivatives or as substances that yield one of these compounds on hydrolysis.
Both ribose and ribulose are monosaccharides. Monosaccharide’s or simple sugars consists of a carbon chain with number of hydroxyl groups plus either an aldehyde (-CHO) or a ketone group(=C=O).
Similarities between Ribose and Ribulose
1. Both are monosaccharides or simple sugars
2. The chemical formula or composition is the same C5H10O5. They are structural isomers.
3. Both are pentoses (5 carbon containing sugars)
4. Both this compounds are biologically important
Ribose and Ribulose
Differences between Ribose and Ribulose  (Refer figure and see the Carbon numbering in red)
1. Ribose is an aldose sugar (with an aldehyde group –CHO) or ribose is an aldopentose
    Ribulose is a ketose sugar (with a keto group (=C=O) or ribulose is ketopentose.
2. The chemical formula of ribose and ribulose is C5H10O5. But are structurally different. They are structural isomers.   
  Structural isomers are compounds with same chemical composition but differ in structure
3. In ribose, the double bond is on the first carbon.
    In ribulose, the second carbon has the double bond
4. Ribose sugar forms the backbone of ribonucleic acid (RNA) 
    Ribulose biphosphate is the initial CO2 acceptor in dark reaction or Calvin cycle of photosynthesis.


We Love to hear from U :) Leave us a Comment to improve this site
Thanks for Visiting.....

  1. In difference 1, I think the ketose should be represented as -C=O and not =C=O

  2. Also discuss their ring structures.


Post a Comment

We Love to hear from U :) Leave us a Comment to improve this site
Thanks for Visiting.....

Previous Post Next Post