Semiconservative replication

From WikiMD's Wellness Encyclopedia

Semiconservative replication is a method of DNA replication in which the original strands of DNA are separated, each serving as a template for the synthesis of a complementary strand. This process results in two copies of the original DNA molecule, each containing one of the original strands and one new strand. This method of replication was first demonstrated by Matthew Meselson and Franklin Stahl in 1958.

Overview[edit | edit source]

Semiconservative replication begins with the unwinding of the double helix to expose the bases in each strand of DNA. This is facilitated by the enzyme helicase. The unwinding of the helix creates a 'Y' shaped structure known as a replication fork.

At the replication fork, the enzyme DNA polymerase begins to synthesize a new strand of DNA using the original strand as a template. The synthesis of the new strand occurs in the 5' to 3' direction. This means that the new strand is synthesized in a direction opposite to the way the original strand is read.

The result of semiconservative replication is two DNA molecules, each composed of one original strand and one newly synthesized strand. This ensures that the genetic information is preserved and accurately passed on to the next generation.

Meselson-Stahl Experiment[edit | edit source]

The semiconservative model of DNA replication was first proposed by James Watson and Francis Crick. However, it was the Meselson-Stahl experiment that provided the experimental evidence to support this model.

In their experiment, Meselson and Stahl grew bacteria in a medium containing a heavy isotope of nitrogen (Nitrogen-15). They then transferred the bacteria to a medium containing a lighter isotope (Nitrogen-14). After several generations, they extracted the DNA from the bacteria and analyzed it using density gradient centrifugation.

The results of the experiment showed that the DNA extracted from the bacteria contained a mixture of heavy and light DNA, supporting the semiconservative model of DNA replication.

See Also[edit | edit source]

References[edit | edit source]

Semiconservative replication Resources
Wikipedia
WikiMD
Navigation: Wellness - Encyclopedia - Health topics - Disease Index‏‎ - Drugs - World Directory - Gray's Anatomy - Keto diet - Recipes

Search WikiMD

Ad.Tired of being Overweight? Try W8MD's physician weight loss program.
Semaglutide (Ozempic / Wegovy and Tirzepatide (Mounjaro / Zepbound) available.
Advertise on WikiMD

WikiMD's Wellness Encyclopedia

Let Food Be Thy Medicine
Medicine Thy Food - Hippocrates

Medical Disclaimer: WikiMD is not a substitute for professional medical advice. The information on WikiMD is provided as an information resource only, may be incorrect, outdated or misleading, and is not to be used or relied on for any diagnostic or treatment purposes. Please consult your health care provider before making any healthcare decisions or for guidance about a specific medical condition. WikiMD expressly disclaims responsibility, and shall have no liability, for any damages, loss, injury, or liability whatsoever suffered as a result of your reliance on the information contained in this site. By visiting this site you agree to the foregoing terms and conditions, which may from time to time be changed or supplemented by WikiMD. If you do not agree to the foregoing terms and conditions, you should not enter or use this site. See full disclaimer.
Credits:Most images are courtesy of Wikimedia commons, and templates Wikipedia, licensed under CC BY SA or similar.

Contributors: Prab R. Tumpati, MD