3. which of the following are necessary for a healthy diet?

minerals and vitamin b
vitamins and lipids
nutrients and iron
all of the above

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.

friedrich meischer discovered it in white blood cell