DNA has four "letters" that must specify the 20 different amino acids that make up proteins. Combinatorially, using three DNA letters for one amino acid makes the most sense.
Duration: 1 minutes, 7 seconds
Once the DNA double helix had been discovered, the next big challenge was to work out how the four letters of DNA could code for each of the twenty amino acids that make protein. The first question was how many DNA letters coded for each amino acid? If it was one DNA letter for one amino acid then you could only code for a maximum of four amino acids. Two letters in every possible combination could code for up to sixteen amino acids. Still, not enough. But three DNA letters provide more than enough combinations to code for all twenty amino acids. So three was the answer. It was a triplet code.
dna double helix,triplet code,dna letters,dna code,amino acids,code pieces,pieces of the puzzle,four letters,location code,amino acid,genetic code,codon,two letters,narration,combinations,protein,animation
Three DNA nucleotides form a codon and specifiy amino acids.
Several researchers crack the genetic code.
An animation shows how the DNA genetic "code" is made into protein.
3D animation of translation: RNA to protein.
Marshall Nirenberg talks about the RNA code for phenylalanine.
Translation: RNA to protein, 3D animation with no audio
Decode a protein.
Because it contains the directions for assembling the components of the cell, DNA is often thought of as the "instruction book" for assembling life.
Transcription factors bind to DNA, RNA polymerase begins transcribing messanger RNA (mRNA) molecule from DNA.
George Gamow was a physicist who became interested in biology after reading Watson and Crick's 1953 paper on DNA structure. Marshall Nirenberg talks about Gamow's theories on the code.