Question

For some time it was not clear whether lac repressor inhibits lac operon transcription by inhibiting the binding of RNA polymerase to its promoter or by allowing transcription initiation but blocking elongation past the site of bound repressor.
How might you distinguish between these possibilities? Fill in the blanks with the options given to complete the following sentences.

in one gel, in separate gels, Northern blot, repressor, Western blot, inducer

Incubate a plasmid containing the lac operon with lac ________. Then add RNA polymerase and Northern blot analyze the mixture by gel electrophoresis and probe the gel ________ with antibodies to RNA polymerase and repressor ________.

Answer 1

Answer:

Incubate a plasmid containing the lac operon with lac __REPRESSOR______. Then add RNA polymerase and Northern blot analyze the mixture by gel electrophoresis and probe the gel _WESTERN BLOT_______ with antibodies to RNA polymerase and repressor _IN SEPERATE GELS_______.

Explanation:

Incubate a plasmid containing the lac operon with lac __REPRESSOR______. Then add RNA polymerase and Northern blot analyze the mixture by gel electrophoresis and probe the gel _WESTERN BLOT_______ with antibodies to RNA polymerase and repressor _IN SEPERATE GELS_______.