The DNA of virtually every cell is underwound (i.e., negatively supercoiled) relative to B-form DNA. In bacteria, an enzyme called (a) _____ introduces negative supertwists into DNA using (b) _____ as a source of energy. This enzyme is classified as a type (c) _____, which affects the linking number in steps of (d) _____. The usual substrate for this enzyme within an E. coli cell is the bacterial chromosome. This circular DNA molecule of 4,700,000 base pairs has a linking number of approximately (e) _____ when it is closed and relaxed. This enzyme would (f) _____ (decrease/increase/not change) this linking number when acting upon this DNA molecule in the presence of the above energy source.

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The Answer of The DNA of virtually every cell is underwound (i.e., negatively supercoiled) relative to B-form DNA. In bacteria, an enzyme called (a) _____ introduces negative supertwists into DNA using (b) _____ as a source of energy. This enzyme is classified as a type (c) _____, which affects the linking number in steps of (d) _____. The usual substrate for this enzyme within an E. coli cell is the bacterial chromosome. This circular DNA molecule of 4,700,000 base pairs has a linking number of approximately (e) _____ when it is closed and relaxed. This enzyme would (f) _____ (decrease/increase/not change) this linking number when acting upon this DNA molecule in the presence of the above energy source.

The DNA of Virtually Every Cell Is Underwound (I