Discovered by H.M. Roulle in 1773, urea is the chief constituent of urine.
Wrong. Water is the chief constituent of urine. Duh!
The bases are nitrogenous because their chemical activity is determined by the electrons of the nitrogen atom, and they are bases because they are one of two great chemical clans—the other being the acids, with which they combine to form salts.
This is chemical nonsense. They are nitrogenous because they contain nitrogen; it has nothing to do with 'chemical activity'.
Proteins are formed from the alpha-amino acids, of which there are twenty in living systems.
Nope. There are far more than 20 alpha amino acids in living systems.
It was Francis Crick who in 1957 first observed that this was most unlikely. In a note circulated privately, Crick wrote that “if one considers the physico-chemical nature of the amino-acid side chains, we do not find complementary features on the nucleic acids. Where are the knobby hydrophobic . . . surfaces to distinguish valine from leucine and isoleucine? Where are the charged groups, in specific positions, to go with acidic and basic amino acids?”
It turns out Crick may have been wrong. There does indeed to be a specific interaction between triplet codons and amino-acid for which they code. This may be a molecular fossil that predates tRNA. No one has ever seen a ribozyme able to undertake chemical action without a suite of enzymes in attendance.
This is quite simply false.
The nucleic acids cannot directly recognize the amino acids (and vice versa), but they cannot directly replicate or transcribe themselves, either.
Again, this is false. There is now strong experimental evidence that RNA triplets do recognize the specific amino acids they code for. And self-replicating ligase ribozymes have been discovered.
It's also a shame to see one more rehash of the same tired and specious probabilistic arguments, and the same argument from incredulity.
Egad! Crick's comments were 50 years ago - meaningless to a Creationist, but critical in Science, especially molecular biology.
Heck, without those, creationists wouldn't have very much to post....