What kind of cells in lgn compute chromatic differences, such as (l-m) and (m-l)? a. bipolar cells b. cone-opponent cells c. rod-opponent cells d. amacrine cells e. stereo cells?

answer; atp and nadph;

many other transport proteins, often called pumps, move materials against a concentration gradient. active transport drives molecules across a membrane from a region of lower concentration to a region of higher concentration. this process, shown in figure 5.1, uses transport proteins powered by chemi- cal energy.