What is the relationship between codon and gene.
A codon consists of 3 consecutive bases in mRNA, with those 3 bases coding for a particular amino acid (or "stop"). Examples of codons would be AGU, AAG, CGU, GCA, etc.
The mRNA is transcribed from DNA, so each codon in mRNA is complementary to a triplet (not a codon, because it is not mRNA) of DNA bases. Complementary just means that the base pairing rules are follows: G bonds with C, and A bonds with U (in RNA) or T (in DNA).
The protein-coding region of a gene (the exons) is composed of triplets.
Okay, so here is the general process. for eukaryotes.
A gene is transcribed into a pre-mRNA. It is then edited, which includes removing the introns (non-coding regions) and splicing together the remaining exons (protein-coding regions). The DNA triplets that make up the protein-coding part of a single gene remain in the complementary mRNA molecule as codons, and the mRNA is exported out of the nucleus. In a complex process that I won't cover in much detail, the order of codons in the mRNA specifies the order that amino acids are added to a growing polypeptide, and thus, specify what protein is made.
The relationship between codon and gene is that a codon is a specific sequence of three nucleotides in DNA or RNA, while a gene is a specific sequence of nucleotides that encodes a functional product, such as a protein.
In simpler terms, a gene is a larger segment of DNA that contains instructions for creating a specific protein or RNA molecule, while a codon is a smaller segment within the gene that specifies a particular amino acid or a start/stop signal during protein synthesis. Multiple codons are used within a gene to create a sequence of amino acids, which ultimately form a protein.
Genes can contain multiple codons, and each codon corresponds to a specific amino acid or a control signal. The sequence of codons within a gene determines the order of amino acids in the resulting protein, which is crucial for its structure and function. Thus, codons and genes are closely related as codons are the building blocks within genes that provide the instructions for protein synthesis.
The relationship between codons and genes is quite important in biology. To understand this relationship, let's start with some basic concepts.
A gene is a specific segment of DNA that contains instructions for creating a particular protein. Genes are the functional units of heredity and play a fundamental role in determining the characteristics and traits of living organisms.
On the other hand, a codon is a sequence of three nitrogenous bases (adenine, thymine, cytosine, or guanine) found in mRNA (messenger RNA). These codons determine the sequence of amino acids during protein synthesis.
Now, the relationship between codons and genes is as follows:
1. Transcription: The process of converting DNA into RNA is called transcription. During this process, an RNA molecule called messenger RNA (mRNA) is synthesized. The mRNA is complementary to the DNA sequence from which it is transcribed, except that thymine (T) in DNA is replaced by uracil (U) in RNA. Each codon in the mRNA represents a specific sequence of three bases.
2. Protein Synthesis: After transcription, the mRNA molecule moves from the nucleus to the cytoplasm, where it acts as a template for protein synthesis. This process is called translation. In translation, the ribosome reads the mRNA codons, and each codon is recognized by a complementary sequence of three bases in a transfer RNA (tRNA) molecule. This tRNA molecule carries a specific amino acid corresponding to the codon being read. The ribosome then links the amino acids together in the correct order to form a protein, based on the sequence of codons in the mRNA.
3. Genetic Code: The relationship between codons and amino acids is defined by the genetic code. The genetic code is a set of rules that governs the translation of mRNA codons into amino acids during protein synthesis. There are 64 possible codons (4 bases in groups of 3), which specify only 20 different amino acids found in proteins. Some amino acids have multiple codons, while others have only one. Additionally, the genetic code also includes start and stop codons that indicate the beginning and end of protein synthesis.
In summary, genes contain the instructions for protein synthesis, and codons are the units within mRNA that specify the sequence of amino acids in a protein. The relationship between codons and genes is crucial for understanding the process by which genetic information is translated into functional proteins.