BIL 150 Lecture Notes - Lecture 17: Ribosomal Rna, Base Pair, Tata Box
Document Summary
A primary transcript is the initial rna transcript from any gene prior to processing. The central dogma is the concept that cells are governed by a cellular chain of command. Rna can also make dna by using enzyme reverse transcription. Triplet code: three nucleotide code for one amino acid. Smallest units of uniform length that can code for all 20 amino acids. During translation the mrna base triplets, called codons, are read in the 5" to 3" direction. Each codon specifies the amino acid to be placed at the corresponding position along a polypeptide. There is no physical barrier that tells where to stop coding, it is continuous. Three nucleotides in a row on a dna strand is therefore referred to as a codon. Because dna consists of four different bases, and because there are three bases in a codon, and because 4 * 4 * 4 = 64, there are 64 possible patterns for a codon.