B. Right but not significant – indeed, examining the purified protein indicates the right size of the proton pump. (By comparing the bands in appeared in the lysate of the food vacuole to this band, we can estimate (based on size comparison) whether the examined band is the proton pump.) However, the gel includes a size marker which contains bands of known molecular weight. The marker allows us to estimate the size of the proteins in the adjacent lanes by comparing them to size marker bands.

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