The 5’–3’ exonuclease activity removes the RNA primer while simultaneously replacing it with a DNA sequence extended from the 3’–OH end of the next Okazaki fragment. 

TLS Online TPP Program

#Id: 7074

#Unit 3. Fundamental Processes

 Valyl-tRNA synthetase can sterically exclude isoleucine from its catalytic pocket because isoleucine is larger than valine. In contrast, valine should slip easily into the catalytic pocket of the isoleucyl-tRNA synthetase. Although both amino acids will fit into the isoleucyl-tRNA synthetase amino acid–binding site, interactions with the extra bonding with tyrosine’s OH group. Since no other amino acid resembles tyrosine, the enzyme can do without an editing function

TLS Online TPP Program

#Id: 621

#Unit 2. Cellular Organization

Attenuator riboswitch (Leader sequence) region 1 is translated  till UGA (R1-2) at high trp concentration due to two conditions

1. Ribosome quickly crosses codon 10, 11

2. After crossing codon 10, 11 ribosome prematurely terminated at UGA at the end of Region 1

TLS Online TPP Program

#Id: 813

#Unit 3. Fundamental Processes

A consensus sequence is, in each case a version of the sequence having at each position the nucleotide (or amino acid) most commonly found. consensus sequence was derived by aligning 300 sequences known to function as s70 promoters and ascertaining the most common base found at each position in the –35 and –10 hexamers.

TLS Online TPP Program

#Id: 2983

#Unit 3. Fundamental Processes

All prokaryotic and eukaryotic DNA polymerases share the same fundamental type of synthetic activity, antiparallel synthesis from 5' to 3' from a template that is 3' to 5'.

TLS Online TPP Program

#Id: 849

#Unit 2. Cellular Organization

Erwinia is necrotrophic bacteria that deploy pectic enzymes cause extensive cell death and tissue maceration.