How the Genetic Code was cracked. Har Gobind Khorana, 89, MIT biochemist, has died. In 1968, he shared the Nobel prize with Marshall Nurenberg and Robert Holley for working out the “blueprint of life”.
• After the structure of DNA was solved in the 50’s, the challenge was to figure out how it encoded information.
• There are 4 letters in DNA (A, C, T and G) that can be strung together in any combination or length.
• There are 20 amino acids in proteins, that can also be combined in any order.
• The minimal “codon” would need a triplet of 4 letters, giving 64 combinations (4x4x4), sufficient to code all 20 amino acids. Some have multiple codes, and there are stop codons.
• Khorana synthesized strands of precise combination of nucleotides that when translated into protein, revealed the code.
Khorana rose from humble origins from a village in India. In 1970 he painstakingly synthesized the first artificial gene that could work in a cell, a landmark achievement at the time.
An announcement, yesterday, shows the amazing progress in synthetic biology: Johns Hopkins scientists have teamed up with China’s BGI to artificially synthesize a complete eukaryotic genome, paving the way for better bioproduction of chemicals, energy and food.
madame scientist's not-so-mad musings 
Hey Rajini Rao , what would be a good text book to get my head around what you are talking about?
Sure, Suhail Manzoor ..do you want something at the intro college level ..higher or lower? Bruce Albert’s Molecular Biology of the Cell is what we use as background reading for first year grad/med students. It is cleanly laid out. I may also be able to find a good video on this. Let me check.
Suhail Manzoor Albert’s Molecular Biology of the Cell was our bible during undergrad – still my favourite textbook 😀 You can also access it for free on NCBI – http://www.ncbi.nlm.nih.gov/books/NBK21054/ (you can search for topics but you cannot browse).
Thank you Rajini Rao & Buddhini Samarasinghe . Alberts it is. I have my reading sorted out for most of next year now. Just thinking about the size of this tome makes me feel smarter. I have a feeling my favourite chapter is going to be “Control of Gene Expression” 🙂
Tony Bryson , I wouldn’t knock Wikipedia..it’s come to my rescue too many times!