Which of these molecular structures could be found in a lipid, but not in a carbohydrate, protein, or nucleic acid? A. a long chain of carbon, oxygen, and nitrogen atoms B. a long chain made only of carbon and hydrogen atoms C. a phosphate group joined to a chain of carbon atoms D. an amino group and a carboxyl group bonded together

Knowing the importance of the essential elements, why would someone chose a diet that does not address all of them?

One drawback of dams is that they can flood land upstream from the dam and reduce water flow downstream from the dam. a. true b. false

Which of the following describe the role a biochemical pump plays in active transport? a it prevents water from moving across the cell membrane. b it uses energy to move materials across the cell membrane against the concentration gradient. c it large molecules cross the cell membrane without using energy. d it a cell move molecules from an area of higher concentration to an area of lower concentration.