Question

Which explains why ornithine is unlikely to be found in proteins synthesized in vivo?

1) there's no codon for it in the standard genetic code
2) it can't form a peptide bond
3) it's not available in the diet
4) it has a net positive charge in aqueous solution

Answer 1

Ornithine is unlikely to be found in proteins synthesized in vivo due to the absence of a codon for it in the genetic code and its net positive charge in aqueous solution.

Step-by-step explanation:

Ornithine is unlikely to be found in proteins synthesized in vivo because there is no codon for it in the standard genetic code. The genetic code is the set of rules by which DNA or mRNA sequences are translated into proteins. It specifies the correspondence between codons (sequences of three nucleotides) and the amino acids they encode. Since ornithine does not have a codon, it cannot be incorporated into proteins during protein synthesis.

In addition to this, ornithine has a net positive charge in aqueous solution. Amino acids with net charges are usually involved in specific cellular processes, but they are not typically found as building blocks of proteins. The majority of proteins are composed of amino acids with no net charge or with a net negative charge.