Department of Energy Argonne National Laboratory Office of Science NEWTON's Homepage NEWTON's Homepage
NEWTON, Ask A Scientist!
NEWTON Home Page NEWTON Teachers Visit Our Archives Ask A Question How To Ask A Question Question of the Week Our Expert Scientists Volunteer at NEWTON! Frequently Asked Questions Referencing NEWTON About NEWTON About Ask A Scientist Education At Argonne Uracil 
Name: Jazir
Status: Other
Grade:  Other
Location: N/A
Country: N/A
Date: August 2007
Question:
Why does RNA has uracil instead of thymine?


Replies:
The difference between thymine and uracil is a single methyl group in thymine that does not appear in uracil, in fact, the chemical name of thymine is 5-methyl uracil. This methyl group is located in a region of thymine that is not involved in Hydrogen bonding to adenine so it behaves just like uracil. The reason why DNA and RNA are different, only God knows!

Ron Baker, Ph.D.

The backbone of RNA is a ribose sugar rather than a deoxyribose sugar that identifies DNA. "Deoxy" refers to the fact that it is a ribose sugar missing an oxygen atom. It has been shown that thymine will not bond correctly with the ribose sugar backbone configuration. Uracil will and acts as a functional substitute. Guanine, cytosine and adenine will bond with either.

Since you have failed to identify your age. You will have to be happy with this explanation.

Steve Sample


Click here to return to the Molecular Biology Archives

NEWTON is an electronic community for Science, Math, and Computer Science K-12 Educators, sponsored and operated by Argonne National Laboratory's Educational Programs, Andrew Skipor, Ph.D., Head of Educational Programs.

For assistance with NEWTON contact a System Operator (help@newton.dep.anl.gov), or at Argonne's Educational Programs

NEWTON AND ASK A SCIENTIST
Educational Programs
Building 360
9700 S. Cass Ave.
Argonne, Illinois
60439-4845, USA
Update: June 2012
Weclome To Newton

Argonne National Laboratory