Francis Crick
Francis Crick
Francis Harry Compton Crick OM FRSwas a British molecular biologist, biophysicist, and neuroscientist, most noted for being a co-discoverer of the structure of the DNA molecule in 1953 with James Watson. Together with Watson and Maurice Wilkins, he was jointly awarded the 1962 Nobel Prize in Physiology or Medicine "for their discoveries concerning the molecular structure of nucleic acids and its significance for information transfer in living material"...
NationalityEnglish
ProfessionScientist
Date of Birth8 June 1916
Francis Crick quotes about
act certain chain english-scientist messenger secondary seems since single virtually
It seems virtually certain that a single chain of RNA can act as messenger RNA, since poly U is a single chain without secondary structure.
assuming certain code deduce english-scientist information limited using
By using polymers of different composition and assuming a triplet code one can deduce limited information about the composition of certain triplets.
acid groups backbone
How is the base sequence, divided into codons? There is nothing in the backbone of the nucleic acid, which is perfectly regular, to show us how to group the bases into codons.
minorities may acid
The meaning of this observation is unclear, but it raises the unfortunate possibility of ambiguous triplets; that is, triplets which may code more than one amino acid. However one would certainly expect such triplets to be in a minority.
simplicity tools use
While Occam's razor is a useful tool in the physical sciences, it can be a very dangerous implement in biology. It is thus very rash to use simplicity and elegance as a guide in biological research.
thinking arrogance ruthlessness
Jim and I hit it off immediately, partly because our interests were astonishingly similar and partly, I suspect, because a certain youthful arrogance, a ruthlessness, an impatience with sloppy thinking can naturally to both of us.
thinking class simplicity
For simplicity one can think of the + class as having one extra base at some point or other in the genetic message and the - class as having one too few.
determination acid would-be
Unfortunately it makes the unambiguous determination of triplets by these methods much more difficult than would be the case if there were only one triplet for each amino acid.
double-standard combination form
If poly A is added to poly U, to form a double or triple helix, the combination is inactive.
trying too-much messages
Again the message to experimentalists is: Be sensible but don't be impressed too much by negative arguments. If at all possible, try it and see what turns up. Theorists almost always dislike this sort of approach.
reading two messages
If, for example, all the codons are triplets, then in addition to the correct reading of the message, there are two incorrect readings which we shall obtain if we do not start the grouping into sets of three at the right place.
dna years add
Finally one should add that in spite of the great complexity of protein synthesis and in spite of the considerable technical difficulties in synthesizing polynucleotides with defined sequences it is not unreasonable to hope that all these points will be clarified in the near future, and that the genetic code will be completely established on a sound experimental basis within a few years.
agreement acid mutation
A comparison between the triplets tentatively deduced by these methods with the changes in amino acid sequence produced by mutation shows a fair measure of agreement.
views order data
Attempts have been made from a study of the changes produced by mutation to obtain the relative order of the bases within various triplets, but my own view is that these are premature until there is more extensive and more reliable data on the composition of the triplets.