Beta Hairpin

Two anti-parallel beta strands connected by a loop / turn, look like hairpin

Can occur independently in isolation

TLS Online TPP Program

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#Unit 3. Fundamental Processes

The maximum absorption of UV by DNA is at a wavelength of 254 nm. Maximum mutagenicity also occurs at 254 nm. 

TLS Online TPP Program

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#Unit 3. Fundamental Processes

Two major products of UV absorption by pyrimidines (thymine and cytosine) are pyrimidine hydrates and pyrimidine dimers.

TLS Online TPP Program

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#Unit 3. Fundamental Processes

Ames Test is used to measure carcinogenicity and mutagenicity of any chemical mutagen.

TLS Online TPP Program

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#Unit 3. Fundamental Processes

The Ames test uses a strain of S. typhimurium that is mutant for the operon responsible for the biosynthesis of the amino acid histidine.

TLS Online TPP Program

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#Unit 3. Fundamental Processes

A more potent mutagen translates into a greater number of revertant colonies.

TLS Online TPP Program

#Id: 654

#Unit 3. Fundamental Processes

Reversal of the mutation can only be done by same mutagen which created forward mutation.