Multiple analytical techniques are required to analyze a protein.
A purified, active preparation of carbonic anhydrase was submitted to native agarose gel electrophoresis at alkaline pH. Three major bands were observed after staining. The same preparation of protein was denatured and submitted to SDS-polyacrylamide gel electrophoresis. One band was observed after staining.
Explain these results.

The band of the SDS-polyacrylamide is the weight of the molecule of that protein.

Explanation:

The native agarose gel electrophoresis is a test know as "Electrophoresis on gel" which help us to analyse the weight of the DNA molecule of proteins, at the end of the gel there´s a positive charge that atracks the negative charge of the DNA molecule of the protein, several bands are seen on the gel at the end of the given time which confirm us the weight of such molecule.

However, to confirm the actual weight there is needed another band which has the actual measured weight (the second test done) in which the band that fits the second band test is the actual weight.

gay

Explanation:

(of a person) homosexual (used especially of a man).

"the city's gay and lesbian people" · [more]

synonyms:

lesbian · lesbigay · LGBT · GLBT · homophile · Uranian · pink · lavender · swinging the other way · queer · that way

dated

lighthearted and carefree.

"Nan had a gay disposition and a very pretty face"

synonyms:

cheerful · cheery · merry · jolly · lighthearted · mirthful · jovial · glad · happy · [more]

offensive

foolish, stupid, or unimpressive.

"making students wait for the light is kind of a gay rule"

NOUN

a homosexual person (typically referring to a man).

"the capital is a popular destination for gays and lesbians from all over the world"

synonyms:

homosexual · lesbian · lesbigay · LGBT · GLBT · homophile · Uranian · pink · lavender · swinging the other way · queer · that way