Search results
Results from the WOW.Com Content Network
An RNA primer is a short chain of single-stranded RNA, consisting of roughly five to ten nucleotides complementary to the DNA template strand. DNA polymerase will then take each nucleotide and make a new complementary DNA strand to the template strand, but only in the 5' to 3' direction. One of the new strands, the leading strand, moves in the ...
The process of semiconservative replication for the site of DNA replication is a fork-like DNA structure, the replication fork, where the DNA helix is open, or unwound, exposing unpaired DNA nucleotides for recognition and base pairing for the incorporation of free nucleotides into double-stranded DNA.
The polymerase chain reaction is the most widely used method for in vitro DNA amplification for purposes of molecular biology and biomedical research. [1] This process involves the separation of the double-stranded DNA in high heat into single strands (the denaturation step, typically achieved at 95–97 °C), annealing of the primers to the single stranded DNA (the annealing step) and copying ...
This build-up creates a torsional load that would eventually stop the replication fork. Topoisomerases are enzymes that temporarily break the strands of DNA, relieving the tension caused by unwinding the two strands of the DNA helix; topoisomerases (including DNA gyrase) achieve this by adding negative supercoils to the DNA helix. [42]
Newly synthesized DNA, otherwise known as Okazaki fragments, are bound by DNA ligase, which forms a new strand of DNA. There are two strands that are created when DNA is synthesized. The leading strand is continuously synthesized and is elongated during this process to expose the template that is used for the lagging strand (Okazaki fragments).
The chemical structure of DNA is insufficient to understand the complexity of the 3D structures of DNA. In contrast, animated molecular models allow one to visually explore the three-dimensional (3D) structure of DNA. The DNA model shown (far right) is a space-filling, or CPK, model of the DNA double helix. Animated molecular models, such as ...
In DNA double helix, the two strands of DNA are held together by hydrogen bonds. The nucleotides on one strand base pairs with the nucleotide on the other strand. The secondary structure is responsible for the shape that the nucleic acid assumes. The bases in the DNA are classified as purines and pyrimidines. The purines are adenine and guanine ...
The double helix is the dominant tertiary structure for biological DNA, and is also a possible structure for RNA. Three DNA conformations are believed to be found in nature, A-DNA, B-DNA, and Z-DNA. The "B" form described by James D. Watson and Francis Crick is believed to predominate in cells. [2]