The plasma membrane has a dual responsibility as a selective ely permeable barrier and transductor. The plasma membrane regulares the traffic of molecules into and out of the cell. Gases and small hydrophobic molecules by passive diffusion transport; Ions, sugars, amino acids, and sometimes water must be transported by a group of integral membrane proteins including
Chapter 11 Cell proliferation and its regulation Significance: 1. For the growth and development of a multicellular organism, and for the generation of offspring; 2. Produce new organisms in unicellular species; 3. Renew the aging, apoptotic cells, and damaged tissue;