[triplet code: the genetic code ..

In 1961 Marshall Nirenberg, a young biochemist at the National Institute of Arthritic and Metabolic Diseases, discovered the first "triplet"—a sequence of three bases of DNA that codes for one of the twenty amino acids that serve as the building blocks of proteins. Subsequently, within five years, the entire genetic code was deciphered.

What Is The Triplet Code? - YouTube

Protein Synthesis & Triplet Code Flashcards | Quizlet

RNA molecule codes for a specific amino acid in protein synthesis

shows the genetic code of the messenger ribonucleic acid (mRNA), i.e. it shows all 64 possible combinations of codons composed of three nucleotide bases (tri-nucleotide units) that specify amino acids during protein assembling.

Each codon of the deoxyribonucleic acid (DNA) codes for or specifies a single amino acid and each nucleotide unit consists of a phosphate, deoxyribose sugar and one of the 4 nitrogenous nucleotide bases, adenine (A), guanine (G), cytosine (C) and thymine (T). The bases are paired and joined together by hydrogen bonds in the double helix of the DNA. mRNA corresponds to DNA (i.e. the sequence of nucleotides is the same in both chains) except that in RNA, thymine (T) is replaced by uracil (U), and the deoxyribose is substituted by ribose.

The process of translation of genetic information into the assembling of a protein requires first mRNA, which is read 5' to 3' (exactly as DNA), and then transfer ribonucleic acid (tRNA), which is read 3' to 5'. tRNA is the taxi that translates the information on the ribosome into an amino acid chain or polypeptide.

For mRNA there are 43 = 64 different nucleotide combinations possible with a triplet codon of three nucleotides. All 64 possible combinations are shown in . However, not all 64 codons of the genetic code specify a single amino acid during translation. The reason is that in humans only 20 amino acids (except selenocysteine) are involved in translation. Therefore, one amino acid can be encoded by more than one mRNA codon-triplet. Arginine and leucine are encoded by 6 triplets, isoleucine by 3, methionine and tryptophan by 1, and all other amino acids by 4 or 2 codons. The redundant codons are typically different at the 3rd base. shows the inverse codon assignment, i.e. which codon specifies which of the 20 standard amino acids involved in translation.

A nucleotide triplet code for amino acids - ScienceDirect

Har Gobind Khorana, at the University of Wisconsin, adapted Nirenberg's experimental system, and confirmed and extended his work. Nirenberg and Khorana were awarded the 1968 Nobel Prize in Physiology or Medicine, shared with Robert W. Holley, "for their interpretation of the genetic code and its function in protein synthesis."

# 35 The genetic code - protein synthesis | Biology …

RNA, the close kin and working partner to DNA, provided the key to the code. While DNA resides almost entirely in the cell nucleus, protein synthesis takes place in the cytoplasm, where RNA is found. On molecular workbenches known as ribosomes, sequences of RNA, transcribed from stretches of DNA, serve as instructions for manufacturing proteins. Protein synthesis represents the fundamental work of the genes.

20/11/2014 · Gene To Protein: The Triplet Code

The basic chemical pathways by which DNA directs synthesis of proteins were clarified by about 1960. But the genetic code—the little language encrypted in molecules of DNA—remained a mystery. Speculation about it was fruitful during the 1950s, but the code was cracked by experiment.

Control of protein synthesis ..