Which of the following constraints affect the stability α-helix, 

a) the intrinsic propensity of an amino acid residue to form an α-helix.

b) the interactions between R groups.

c) the bulkiness of adjacent R groups.

d) the occurrence of Pro and Gly residues.

TLS Online TPP Program

#Question id: 2665

#Unit 2. Cellular Organization

A transposon ____________.

TLS Online TPP Program

#Question id: 2666

#Unit 2. Cellular Organization

A cell does not want to waste energy synthesizing the amino acid arginine if arginine is present in its diet. Therefore, when arginine is present, it activates a repressor protein to prevent transcription of genes that code for enzyme to make arginine. This is an example of what type of regulation?

TLS Online TPP Program

#Question id: 2667

#Unit 2. Cellular Organization

A regulatory protein that attracts RNA polymerase to its promoter is an example of what type of regulation?

TLS Online TPP Program

#Question id: 2668

#Unit 2. Cellular Organization

The toxic shock syndrome toxin is produced by some Salmonella species when there is not sufficient iron present. When iron is present, it prevents transcription of the TSS-toxin gene. Iron therefore serves as __________.

TLS Online TPP Program

#Question id: 2669

#Unit 2. Cellular Organization

what is an operon?

TLS Online TPP Program

#Question id: 2670

#Unit 2. Cellular Organization

A protein that binds to the operator and blocks the RNA polymerase