The Groundbreaking Work of Marshall Nirenberg and Heinrich Matthaei in Cracking the Genetic Code

Marshall Nirenberg and Heinrich Matthaei's Contribution to Cracking the Genetic Code

The groundbreaking work of Marshall Nirenberg and Heinrich Matthaei was crucial in deciphering the genetic code. In 1961, they began experiments with fractionated E. coli to determine the necessary components for polypeptide synthesis in a test tube, a process known as in vitro translation. They discovered that when synthetic mRNA containing only uracil was added to a solution with phenylalanine, a polypeptide consisting solely of phenylalanine was synthesized, thus decoding the first triplet codon UUU for phenylalanine.

Nirenberg and Matthaei's efforts paved the way for the full decoding of the genetic code. Following their initial discovery, they expanded their research, and along with Philip Leder, continued by synthesizing aminoacyl-tRNAs using individual amino acids in separate test tubes. This approach allowed them to decipher the remaining codons of the genetic code.

Ultimately, their work, combined with other scientists such as Har Gobind Khorana and Francis Crick among others, led to the complete understanding of the genetic code, which includes 64 codons, with 61 coding for amino acids and three serving as stop codons. The deciphering of the genetic code is considered one of the most significant achievements of molecular biology, and it has had profound implications on our understanding of life and genetics.

How did Marshall Nirenberg and Heinrich Matthaei crack the genetic code?

Final answer:

Marshall Nirenberg and Heinrich Matthaei cracked the genetic code by translating synthetic mRNAs in vitro, leading to the synthesis of polypeptides. They started with the triplet UUU for phenylalanine and later, with advancements including the work of Philip Leder, deciphered the rest of the codons, culminating in the complete understanding of the genetic code.