The following sections of this BookRags Literature Study Guide is offprint from Gale's For Students Series: Presenting Analysis, Context, and Criticism on Commonly Studied Works: Introduction, Author Biography, Plot Summary, Characters, Themes, Style, Historical Context, Critical Overview, Criticism and Critical Essays, Media Adaptations, Topics for Further Study, Compare & Contrast, What Do I Read Next?, For Further Study, and Sources.
(c)1998-2002; (c)2002 by Gale. Gale is an imprint of The Gale Group, Inc., a division of Thomson Learning, Inc. Gale and Design and Thomson Learning are trademarks used herein under license.
The following sections, if they exist, are offprint from Beacham's Encyclopedia of Popular Fiction: "Social Concerns", "Thematic Overview", "Techniques", "Literary Precedents", "Key Questions", "Related Titles", "Adaptations", "Related Web Sites". (c)1994-2005, by Walton Beacham.
The following sections, if they exist, are offprint from Beacham's Guide to Literature for Young Adults: "About the Author", "Overview", "Setting", "Literary Qualities", "Social Sensitivity", "Topics for Discussion", "Ideas for Reports and Papers". (c)1994-2005, by Walton Beacham.
All other sections in this Literature Study Guide are owned and copyrighted by BookRags, Inc.
Reverse transcription is an atypical method of synthesizing DNA from a template of RNA. Typically, transcription is a unidirectional process in which the nucleotide sequence of one strand of DNA is copied, thereby creating a single strand of RNA with a nearly identical sequence. This RNA strand is then utilized by the cell for a variety of reasons related to the synthesis of proteins and enzymes.
In reverse transcription, the process is reversed. RNA is used as a template to make DNA. This process is performed by certain retroviruses whose genetic code is made up of single-stranded RNA molecules. It also requires a special enzyme known as a reverse transcriptase enzyme. When these viruses infect a cell, they inject it with their RNA. Instead of being utilized in protein synthesis, this RNA goes through the process of reverse transcription, and is converted into a single-stranded DNA molecule. This single-stranded DNA is further converted into a double-stranded DNA that then becomes integrated into the cell's genome. When these foreign genes are expressed, the cell's normal functions are altered and it becomes a manufacturing site for more viruses.
The existence of reverse transcription establishes the general rule that information stored in nucleic acid sequences as either RNA or DNA can be converted between either type. However, reverse transcription does not generally occur in the normal operations of a cell.