Columbus and other Europeans of his time believed that the Earth was
roughly 50 percent smaller than it really is.
roughly 50 percent larger than it really is.
about the same size as it really is.
just slightly smaller than it really is.

What is the significance of the protein-lined pits? a. protein attracts other proteins needed for atp synthesis within the cell. b. protein-lined pits are able to transport one molecule at a time down the concentration gradient within the cell. c. the polarity of proteins allows other polar molecules to attach and be transported in the cell by transport channels. d. receptors within the pits allow ligands to fuse and be transported into the cell by endocytosis.