Explain why the elbow joint of a cow and the elbow joint of a human have similar, but not identical structure. think about the actions each organism completes with this limb.

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.

answer///island,peninsula;