START CODON Meaning and
Definition
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A start codon is a molecular sequence of nucleotides present in an mRNA molecule that marks the beginning of protein synthesis. Proteins are essential for the functioning of cells and are synthesized through a process known as translation. The start codon acts as a signal for the ribosomes, the protein-building machinery of cells, to initiate translation and begin synthesizing a specific protein.
In most organisms, including humans, the start codon is represented by the triplet nucleotide sequence AUG. This codon codes for the amino acid methionine, which is often the first amino acid incorporated into a growing polypeptide chain during protein synthesis.
The start codon is recognized by specific initiation factors that help assemble the ribosomes at the beginning of the mRNA molecule. Once the ribosomes bind to the start codon, they begin the process of scanning the mRNA molecule and translating the genetic information into a functional protein.
Different variations of the start codon exist in certain organisms or contexts. For example, the GUG and UUG codons can function as start codons in some bacteria and mitochondria. In addition, alternative initiation sites within an mRNA molecule can lead to the usage of different start codons, resulting in the production of protein isoforms with slightly different functions.
Overall, the start codon plays a vital role in initiating protein synthesis and is essential for translating the genetic information stored in the mRNA molecule into functional proteins.
Common Misspellings for START CODON
- atart codon
- ztart codon
- xtart codon
- dtart codon
- etart codon
- wtart codon
- srart codon
- sfart codon
- sgart codon
- syart codon
- s6art codon
- s5art codon
- stzrt codon
- stsrt codon
- stwrt codon
- stqrt codon
- staet codon
- stadt codon
- staft codon
- statt codon
Etymology of START CODON
The word "Start Codon" is derived from two main sources.
1. Start: The term "start" comes from the Old English word "styrtan" or "stertan", which means "to jump up" or "to set in motion". This word evolved over time and was influenced by other Germanic languages, eventually leading to the Middle English word "starten" with similar meanings. In the context of molecular biology, "start" refers to the initiation or beginning of a process.
2. Codon: The term "codon" is derived from the combination of "c" for "cistron" and "odon" for "region". It was coined by the American geneticist Severo Ochoa in 1957.
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