Retention factor (k) is simply the additional time that the analyte takes to elute from the column relative to an unretained or excluded analyte that does not interact with the stationary phase and which, by definition, has a k value of 0. Thus

TLS Online TPP Program

#Id: 7065

#Unit 3. Fundamental Processes

The addition of the 3’-CCA is catalyzed by the enzyme tRNA nucleotidyltransferase, which functions as a nontemplate-directed RNA polymerase.

TLS Online TPP Program

#Id: 7066

#Unit 3. Fundamental Processes

Multiple tRNAs representing the same amino acid are called isoaccepting tRNAs; because they are all recognized by the same synthetase, they are also described as its cognate tRNAs.

TLS Online TPP Program

#Id: 7067

#Unit 3. Fundamental Processes

TLS Online TPP Program

#Id: 7068

#Unit 3. Fundamental Processes

Class I enzymes attach the amino acid to the 2’-OH of the tRNA and are generally monomeric. Class II enzymes attach the amino acid to the 3’-OH of the tRNA and are typically dimeric or tetrameric.The amino acids for which the Class I synthetases are specific tend to be larger and more hydrophobic than those for Class II synthetases.

TLS Online TPP Program

#Id: 7069

#Unit 3. Fundamental Processes

TLS Online TPP Program

#Id: 7070

#Unit 3. Fundamental Processes