Genetic Code: Definition, Steps, Types and Examples

What Is Genetic Code?

The genetic code is one definition of the set of rules by which information that is encoded in the genetic material, either DNA or RNA sequences, is translated into proteins by living cells. This language is universal in guiding the synthesis of proteins, the building blocks of life, from information contained in genes. The genetic code is known to be core biology and heredity because it speaks about how the transfer of information from one generation to another takes place genetically and how it dictates the structure and function of proteins.

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This Story also Contains

1. What Is Genetic Code?
2. Diagram Of Genetic Code
3. Basic Concepts Of Genetic Code
4. Transcription Process
5. Translation Process
6. Properties Of The Genetic Code
7. Non-Overlapping And Commaless
8. Mutations And The Genetic Code
9. Recommended video for Genetic Code
10. Applications Of Knowing The Genetic Code

Diagram Of Genetic Code

Deciphering the genetic code is truly one of the cornerstones of molecular biology. James Watson and Francis Crick explained the DNA double helix in 1953, doing much to help our understanding of genetics. In 1961, Marshall Nirenberg and Heinrich Matthaei deciphered the first codon. Other scientists performed experiments that soon disclosed the remaining genetic code.

Several Nobel Prizes have been awarded for work on the genetic code. In 1962, Watson, Crick, and Maurice Wilkins were awarded the Nobel Prize in Physiology or Medicine for their discovery that identified the molecular structure of nucleic acids. In 1968, Nirenberg, Robert Holley, and Har Gobind Khorana were awarded Nobel Prizes for their interpretation of the genetic code and its function in protein synthesis.

Basic Concepts Of Genetic Code

Some basic concepts are as follows:

DNA And RNA Basics

DNA is deoxyribonucleic acid, and RNA is ribonucleic acid. These are nucleic acids that store and transmit genetic information. DNA is a double-stranded molecule that acts as a long-term storage, whereas RNA is mostly single-stranded; it works both as a messenger and functional molecule in protein synthesis.

Nucleotides And Bases

Nucleotides are the basic building blocks of nucleic acids. Each nucleotide is made up of a sugar, phosphate group, and nitrogenous base. For DNA bases, there are adenine (A), thymine (T), cytosine (C), and guanine (G). In RNA, uracil replaces thymine.

Codons And Anticodons

A codon is a series of three nucleotides in the mRNA that code for a specific amino acid or an amino acid termination signal during protein synthesis. The sequence complementary to the codon on the tRNA molecule--the anticodon--guarantees that the correct amino acid is brought into the sequence of the growing polypeptide chain.

Transcription Process

Transcription is a process wherein the transfer of the genetic code in DNA gets copied into mRNA. The RNA polymerase binds to DNA and synthesizes a complementary RNA strand. Such formed mRNAs take the carried genetic information out of the nucleus to the ribosomes, where the process of protein synthesis takes place.

Translation Process

Translation is the process through which mRNA gets converted to a protein. The sequence of mRNA is read in codons by the ribosomes while the appropriate amino acids are brought to the ribosome by tRNA molecules. These amino acids get assembled into a polypeptide chain by the ribosome and fold into a functional protein.

Properties Of The Genetic Code

The major properties of the genetic code are:

Universality

This roughly universal genetic code means that the same codons would come to specify the same amino acids in almost all species. This universality also led to the hypothesis regarding a common origin of life.

Degeneracy

The genetic code is degenerate, meaning multiple codons code for the same amino acid. It is this redundancy that protects against mutations: some changes in the DNA sequence do not alter the resulting protein.

Non-Overlapping And Commaless

The reading of genetic code occurs in a continuous, nonoverlapping fashion, without spacing or punctuation marks thereby separating codons from one another. This was a mechanism to ensure perfect and efficient translations of mRNAs at all times into proteins.

Mutations And The Genetic Code

Mutations predispose changes in the DNA sequence in the genetic code hence influencing protein synthesis. Types of mutations include point mutations a single nucleotide substitution, insertion and deletion. The effects of these types on the function of proteins are variable.

Effects Of Mutations

The different effects of mutations are silent mutations, which do not have any effect on the protein; missense mutations, where there is a change in just one amino acid; and nonsense mutations, which introduce an improper stop codon. Genetic mutations can lead to inherited diseases and disorders. For instance, cystic fibrosis and sickle cell anaemia are two genetic disorders brought about by certain genetic mutations.

Recommended video for Genetic Code

Applications Of Knowing The Genetic Code

Advances in understanding the genetic code have prompted radical technologies like CRISPR, which enables very high-precision editing of genes. This makes several applications possible within agriculture—in GMOs—and medicine for the creation of new treatments but more generally in industry, notably for the production of biofuels and bioplastics.

Medical And Clinical Studies

The knowledge of the genetic code plays a vital role in comprehending genetic diseases and designing gene therapies. Gene therapy is essentially treating or preventing diseases by correcting a gene when it is malfunctioning. It gives hope for some disease conditions that are incurable at present.

Conclusion

Genetic code has represented the universal set of instructions for translating genetic information into proteins. Fully understanding what it was, how it was discovered, and its structure, properties, and functions remains very important and substantially investigates the future progress of biology, medicine, and biotechnology.