Relate the four chemicals on the rungs of a dna ladder to the letters of our alphabet. describe the code these "letters" can form. what does the code do?

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.