* DNA ligase I: ligates the nascent DNA of the lagging strand after the Ribonuclease H has removed the RNA primer from the Okazaki fragments.

To be more specific, the leading strand receives one RNA primer per active origin of replication while the lagging strand receives several ; these several fragments of RNA primers found on the lagging strand of DNA are called Okazaki fragments, named after their discoverer.

RNase removes the RNA fragments used to initiate replication by DNA polymerase, and another DNA Polymerase enters to fill the gaps.

Gel electrophoresis is a method used in clinical chemistry to separate proteins by charge and or size ( IEF agarose, essentially size independent ) and in biochemistry and molecular biology to separate a mixed population of DNA and RNA fragments by length, to estimate the size of DNA and RNA fragments or to separate proteins by charge.

An RNA ladder is often run alongside the samples on an electrophoresis gel to observe the size of fragments obtained but in total RNA samples the ribosomal subunits can act as size markers.

In this procedure, the substrate nucleic acid ( that is affixed to the membrane ) is a collection of isolated DNA fragments, and the probe is RNA extracted from a tissue and radioactively labelled.

The use of DNA microarrays that have come into widespread use in the late 1990s and early 2000s is more akin to the reverse procedure, in that they involve the use of isolated DNA fragments affixed to a substrate, and hybridization with a probe made from cellular RNA.

Retroposons are repetitive DNA fragments which are inserted into chromosomes after they had been reverse transcribed from any RNA molecule.

To sequence RNA, the usual method is first to reverse transcribe the sample to generate cDNA fragments.

Chromatography and identification of the 5 ' and 3 ' ends then helped arrange the fragments to establish the RNA sequence.

Nucleic acid electrophoresis is an analytical technique used to separate DNA or RNA fragments by size and reactivity.

In the replication process, DNA Polymerase I removes the RNA primer ( created by Primase ) from the lagging strand and fills in the necessary nucleotides between the Okazaki fragments ( see DNA replication ) in 5 ' -> 3 ' direction, proofreading for mistakes as it goes.

Pol I then synthesizes the short DNA fragments that were formerly hybridized to the RNA fragment.

They are separated by ~ 10-nucleotide RNA primers and are unligated until RNA primers are removed, followed by enzyme ligase connecting ( ligating ) the two Okazaki fragments into one continuous newly synthesized complementary strand.

Primase adds RNA primers onto the lagging strand, which allows synthesis of Okazaki fragments from 5 ’ to 3 ’.

The order in which the amino acids are added is read through the genetic code from an mRNA template, which is a RNA copy of one of the organism's genes.

The most common nucleic acids are deoxyribonucleic acid ( DNA ) and ribonucleic acid ( RNA ).

Also, the nitrogenous bases possible in the two nucleic acids are different: adenine, cytosine, and guanine occur in both RNA and DNA, while thymine occurs only in DNA and uracil occurs in RNA.

Of these, only two families have RNA genomes and only five families are enveloped.

In molecular biology and genetics, the linking between two nitrogenous bases on opposite complementary DNA or certain types of RNA strands that are connected via hydrogen bonds is called a base pair ( often abbreviated bp ).

Pairing is the mechanism by which codons on messenger RNA molecules are recognized by anticodons on transfer RNA during protein translation.

The only other purine-pyrimidine pairings would be AC and GT and UA ( in RNA ); these pairings are mismatches because the pattern of hydrogen donors and acceptors do not correspond.

Paired DNA and RNA molecules are comparatively stable at room temperature but the two nucleotide strands will separate above a melting point that is determined by the length of the molecules, the extent of mispairing ( if any ), and the GC content.

Base stacking interactions in DNA and RNA are due to dispersion attraction, short-range exchange repulsion, and electrostatic interactions, which also contribute to stability.

) Base stacking effects are especially important in the secondary structure and tertiary structure of RNA ; for example, RNA stem-loop structures are stabilized by base stacking in the loop region.

The following abbreviations are commonly used to describe the length of a D / RNA molecule:

For case of single stranded DNA / RNA units of nucleotides are used, abbreviated nt ( or knt, Mnt, Gnt ), as they are not paired.

Using pharmacogenomics, pharmaceutical companies can create drugs based on the proteins, enzymes and RNA molecules that are associated with specific genes and diseases.

All known forms of life are based on the same fundamental biochemical organisation: genetic information encoded in DNA, transcribed into RNA, through the effect of protein-and RNA-enzymes, then translated into proteins by ( highly similar ) ribosomes, with ATP, NADH and others as energy sources, etc.

The interior of the nucleus does not contain any membrane-bound subcompartments, its contents are not uniform, and a number of subnuclear bodies exist, made up of unique proteins, RNA molecules, and particular parts of the chromosomes.

* In situ hybridization shows which cells are expressing a particular RNA transcript.

The simplest genophores are found in viruses: these DNA or RNA molecules are short linear or circular genophores that often lack structural proteins.

The local structure of chromatin during interphase depends on the genes present on the DNA: DNA coding genes that are actively transcribed (" turned on ") are more loosely packaged and are found associated with RNA polymerases ( referred to as euchromatin ) while DNA coding inactive genes (" turned off ") are found associated with structural proteins and are more tightly packaged ( heterochromatin ).

The central dogma of molecular biology where genetic material is transcribed into RNA and then translated into protein, despite being an oversimplified picture of molecular biology, still provides a good starting point for understanding the field.

DIG molecules are often linked to uridine nucleotides ; DIG-labelled uridine ( DIG-U ) can then be incorporated into RNA probes via in vitro transcription.

An exon is a sequence of DNA that is expressed ( transcribed ) into RNA and then translated into protein.

The term later came to include sequences removed from rRNA and tRNA, and it also was used later for RNA molecules originating from different parts of the genome that are then ligated by trans-splicing.

If a siRNA is designed to match the RNA copied from a faulty gene, then the abnormal protein product of that gene will not be produced.

RNA samples are then separated by gel electrophoresis.

DNA polymerases are then able to use the free 3 '- OH groups on the RNA primers to synthesize DNA in the 5 '→ 3 ' direction.

When a ( nonendogenous ) retrovirus invades a cell, the RNA of the retrovirus is reverse-transcribed into DNA by reverse transcriptase, then inserted into the host genome by an integrase.

The term is sometimes used to refer only to protein translation but more often it refers to a multi-step process, beginning with amino acid synthesis and transcription of nuclear DNA into messenger RNA, which is then used as input for translation.

The enzyme then progresses along the template strand in the 3 ’ to 5 ’ direction, synthesizing a complementary RNA molecule with elongation occurring in the 5 ’ to 3 ’ direction.

Reverse transcribing viruses replicate their genomes by reverse transcribing DNA copies from their RNA ; these DNA copies are then transcribed to new RNA.

The ribosome then contains three RNA binding sites, designated A, P and E. The A site binds an aminoacyl-tRNA ; the P site binds a peptidyl-tRNA ( a tRNA bound to the peptide being synthesized ); and the E site binds a free tRNA before it exits the ribosome.

In most viruses, DNA is transcribed into RNA, and then RNA is translated into protein.

However, retroviruses function differently-their RNA is reverse-transcribed into DNA, which is integrated into the host cell's genome ( when it becomes a provirus ), and then undergoes the usual transcription and translational processes to express the genes carried by the virus.

The positive-sense RNA molecule then acts as viral mRNA, which is translated into proteins by the host ribosomes.

The idea of reverse transcription was very unpopular at first as it contradicted the central dogma of molecular biology which states that DNA is transcribed into RNA which is then translated into proteins.

Reverse-transcribing RNA viruses, such as retroviruses, use the enzyme to reverse-transcribe their RNA genomes into DNA, which is then integrated into the host genome and replicated along with it.

# Complementary DNA then binds to the U5 ( non-coding region ) and R region ( a direct repeat found at both ends of the RNA molecule ) of the viral RNA