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 DNA Function Advantage over RNA
Name: Fabia
Status: Other
Grade:  Other
Location: TX
Country: United States
Date: April 2006


Question:
Why does DNA make a better material than RNA for storage of genetic information?



Replies:
The most important by far is that DNA is typically double stranded. This has a number of advantages, the most immediate being when one strand breaks the entire molecule doess not fall apart...there are other advantages...if an error is made in one strand on one base the other strand is still there in its original order to help maintain the original sequence on the opposite strand when a correction enzyme comes along to clip out the mismatch.

pf


Both can serve as genetic material; many viruses use RNA as their genetic material. DNA probably evolved as the genetic material for cells so that RNA could be used as messenger RNA which carries the information for protein synthesis to the ribosomes. This way, many "copies" of the gene can be made so that more protein molecules can be synthesized in a short period of time. Also, the mRNA is metabolically unstable because it is rapidly broken down by RNAse. DNA must be stable so RNA had to evolve to fulfill this function.

Ron Baker, Ph.D.


Dear Fabian,

Both DNA and RNA have the same coding capacity. They both are polymers with similar potential length. The answer to your question lies in a form of DNA that commonly exists in all living organisms but is not really common with RNA. Some viruses are exceptional because they exist with a single strand of DNA or with a double strand of RNA.

Jim Tokuhisa, Ph.D.



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