The nurse practitioner working in occupational health has been asked to speak to a group of factory workers about the importance of wearing gloves when working with strong chemicals such as turpentine and paint thinner. Which of the following characteristics of cell membranes underlies the nurse’s teaching?Cell membranes are impermeable to all but lipid-soluble substances.Cell membranes have lipids that have a hydrophilic head and a hydrophobic tail.Cell membranes contain receptors for hormones and biologically active substances.Transmembrane proteins can pass through the cell membrane into the intracellular environment.