Nucleotide
Definition
The monomer unit of nucleic acids. Each nucleotide consists of a five-carbon sugar (deoxyribose in DNA, ribose in RNA), a phosphate group, and one of four nitrogenous bases. Nucleotides are joined by phosphodiester bonds between the 3' carbon of one sugar and the 5' carbon of the next, forming the backbone of the strand.
Related terms
- Antiparallel Orientation
- The two strands of the DNA double helix run in opposite directions: one strand reads 5' to 3', its complement reads 3'...
- Autosomal vs Mitochondrial DNA
- Autosomal DNA is nuclear, biparentally inherited, present as two copies per cell. Mitochondrial DNA is cytoplasmic, maternally inherited, present in hundreds to...
- Base Pair (Bp)
- A complementary pairing of nitrogenous bases on opposite strands of double-stranded DNA: adenine with thymine (two hydrogen bonds) or guanine with cytosine...
- Capillary Electrophoresis
- Size separation of fluorescently labelled PCR products through a polymer-filled capillary on an instrument like the ABI 3500. Output is an electropherogram.
- Chromosome
- A discrete, condensed structure consisting of a single long DNA molecule complexed with histone proteins. Humans normally carry 46 chromosomes in 23...
- CODIS
- The FBI's Combined DNA Index System, the US national STR-based forensic DNA database. Contains profiles from convicted offenders, arrestees, and unidentified crime-scene...
- Complementarity
- The property by which each base pairs with only one specific partner (A with T, G with C). Complementarity allows a single...
- Denaturation
- The separation of double-stranded DNA into two single strands by disrupting the hydrogen bonds between base pairs. In PCR, denaturation is achieved...
- Multiplex STR Kit
- Single-tube PCR amplifying 15+ STR loci plus amelogenin in one reaction. AmpFISTR Identifiler Plus and PowerPlex are the workhorses in Indian DNA...
- PCR
- Polymerase Chain Reaction. Kary Mullis 1983. Exponential amplification of a target sequence using a thermostable Taq polymerase, two primers and thermal cycling.
- Phosphodiester Bond
- The covalent linkage between consecutive nucleotides in a strand, formed between the phosphate group and the 3'-OH of the preceding sugar and...
- RFLP
- Restriction Fragment Length Polymorphism. The first-generation DNA typing method using restriction enzymes and Southern blotting. Required nanograms of intact DNA.
Explained in these topics
- DNA in Forensic Science: Structure, Genetic Markers, Extraction and ProfilingMonomer unit of DNA: a deoxyribose sugar, a phosphate group, and one of four nitrogenous bases (A, T, G, C).
- Nucleic Acids: Structure and FunctionThe monomer unit of nucleic acids. Each nucleotide consists of a five-carbon sugar (deoxyribose in DNA, ribose in RNA), a phosphate group, and one of four nitr...