All cells are surrounded by a plasma membrane composed of lipid and protein molecules.What is the function of the plasma membrane?
E.coli is known as a gram-negative bacterial species.(a)How is this determined? (b)How do gram-negative bacteria differ structurally from gram-positive bacteria?
Most cells of higher plants have a cell wall outside the plasma membrane.What is the function of the cell wall?
(a)List the types of noncovalent interactions that are important in providing stability to the three-dimensional structures of macromolecules.(b)Why is it important that these interactions be noncovalent,rather than covalent,bonds?