Structural Biochemistry/DNA and RNA Terms

Structural Biochemistry DNA and RNA Terms

• NUCLEOSIDE: A nucleoside consists of a sugar and one of the four bases (ATCG) present in DNA
• NUCLEOTIDE: A nucleotide consists of a sugar, one of the four bases (ATCG) present in DNA, and a phosphate, meaning a nucleotide is a nucleoside plus a phosphate.
• SEMI-CONSERVATIVE REPLICATION: The separation of the double helix creates two single-stranded templates onto which new double helices can be made. Therefore in semi-conservative replication the newly made DNA strand is half parental and half constructed.
• TRANSLATION: Translation is the process of protein synthesis. Here messenger RNA or mRNA that originated from transcription is read and interpreted in the ribosome to produce a specific amino acid chain thereby forming a protein.
• TRANSCRIPTION: Transcription is the process of creating an mRNA strand or quite simple an RNA copy of DNA where the base pairs are (AUGC) and RNA polymerase is used to catalyze the formation of the nucleic acid based polymer. The primary transcript of RNA will undergo various alterations like the addition of a Cap, a Poly(A) tail, and splicing to remove introns.
• TRANSFER RNA: Transfer RNA will transfer a specific amino acid to the ribosomal site of protein synthesis during translation. Here an anticodon on the tRNA will match a codon on the mature mRNA strand, which will correspond to a singe particular amino acid.
• MICRO RNA: Micro RNA or miRNA binds to complementary sequences of mRNA and thereby silence or inhibit the translation of that mRNA transcript into a protein.
• MESSENGER RNA: Messenger RNA or mRNA is a molecule that carries the blueprint for the building of a protein. The mRNA strand comes from a copy of DNA and carries with it the coding information for protein synthesis.
• RIBOSOMAL RNA: Ribosomal RNA or rRNA is the major component of RNA that gives the ribosome its ability catalyze the synthesis of amino acids into fully functional proteins.
• SMALL INTERFERING RNA: Small interfering RNA or siRNA is also known as short interfering RNA or silencing RNA because it is involved in RNA interference, which stops the expression of RNA into a protein.
• snRNA: These are small RNA molecules found in eukaryotic cells that are involved in RNA splicing
• SIGNAL RECOGNITION PARTICLE: It is a ribonucleoprotein which recognizes specific proteins and targets them to the endoplasmic reticulum in eukaryotes and the plasma membrane in prokaryotes
• TELOMERASE RNA: RNA is present in the form of a number of repeats of certain nucleotides at the ends of chromosomes in order to protect the DNA from breakage
• RIBOZYME: It is an RNA molecule that has the ability to catalyze a chemical reaction due to the fact that it possesses a definite 3-D structure.
• PURINE: A purine is an aromatic heterocyclic compound. Adenine and guanine are purine ribonucleotides.
• PYRIMIDINE: It is also a class of aromatic heterocyclic compound found in DNA and RNA. Thymine and Cytosine are pyrimidines.
• INTRON: An intron is a noncoding section of RNA that will not be expressed into a protein and must be removed through splicing.
• EXON: An exon is a coding section of RNA that will be expressed into a protein and therefore must be linked together with other exon segments to make a mature RNA transcript.
• Ribose: The pentose sugar found in RNA
• Deoxyribose: The pentose sugar found in DNA
• DNA polymerase: One of the enzymes responsible for DNA replication
• ADENINE: One of the five nucleotides found in DNA and RNA
• THYMINE: One of the nucleotides found in DNA. In RNA, this base is replaced with uracil
• URACIL: One of the nucleotides found in RNA. In DNA, this base is replaced with thymine
• CYTOSINE: One of the nucleotides found in DNA and RNA
• GUANINE: One of the nucleotides found in DNA and RNA
• PCR: Polymerase Chain Reaction - a process by which a specific sequence of DNA is exponentially amplified
• Gel Electrophoresis: A technique used to send fragments of DNA across an agarose gel, separating the fragments by size.
• SOUTHERN BLOT: is a method used for detecting a specific DNA sequence in DNA samples. Southern blotting combines electrophoresis - separating DNA fragments to a filter membrane and subsequent fragment dection by probe.
• NORTHERN BLOT: technique used to detect RNA in a sample. Uses electrophoresis to separate RNA samples by size and dection with probe. Similar to southern blot.

In a DNA, cytosine will link with tyrosine by triple bonds. Guanine will link with adinine by double bond.

References

Berg, Jeremy M., Tymoczko, John L., and Stryer, Lubert. Biochemistry. 6th ed. New York, N.Y.: W.H. Freeman and Company, 2007.