24. which is not true of lipids? they supply cells with energy. they supply cells with nitrogen. they form structural parts of cell membranes. the carry fat-soluble vitamins to cells. 25. paper is made from wood pulp. what carbohydrate makes up paper? starch cellulose sucrose glycogen 26. which type of molecules does the body use to build and repair muscle tissue? lipids proteins nucleic acids carbohydrates 27. why are enzymes important to cells? they form the two layers of membranes. they provide structural support. they store large quantities of energy. they bring about chemical reactions. 28. what holds the two strands of a dna molecule to each other? peptide bonds hydrogen bonds single carbon bonds double carbon bonds 29. what polysaccharide do plants store in plastids? glycogen lactose starch cellulose 30. what is a complete protein? it has at least three of the essential amino acids. it has all nine of the essential amino acids. it has all twenty of the essential amino acids. it has all eleven of the amino acids produced in the body.