(a) Choose one water-soluble and one fat-soluble vitamin. Draw their structures. Give a reference daily intake for each, in milligrams or micrograms. Give at least one metabolic role for each. List the condition caused by a deficiency of each, or describe the effects of a deficiency of each. Give a good dietary source of each. 

(b) Choose one of the following minerals: selenium, molybdenum, zinc. Give a reference daily intake, in milligrams or micrograms. Give at least one metabolic role. List the condition caused by its deficiency, or describe the effects of its deficiency.