A double blind study is the most rigorous clinical research design because, in addition to the randomization of subjects, which reduces the risk of bias, it can eliminate or minimize the placebo effect which is a further challenge to the validity of a study.
Transcription by RNA polymerase. An RNA strand is synthesized in the 5â²âââ3â² direction from a locally single stranded region of DNA. (After E. J. Gardner, M. J. Simmons, and D. P. Snustad, Principles of Genetics, (more...).igure 10-6. Transcription of two genes. (a) RNA polymerase moves from the 3â² end of the template strand, creating an RNA strand that grows in a 5â²âââ3â² direction (because it must be antiparallel to the template strand).
Translation of an mRNA molecule by the ribosome occurs in three stages: initiation, elongation, and termination. During initiation, the small ribosomal subunit binds to the start of the mRNA sequence. Then a transfer RNA (tRNA) molecule carrying the amino acid methionine binds to what is called the start codon of the mRNA sequence. The start codon in all mRNA molecules has the sequence AUG and codes for methionine.