Cell Biology Membranes and Chemical Transport: Absorption, distribution, and storage of substances in organisms by Morris S. Zedeck, Ph.D. Reading Quiz Teach with this 1. The water soluble phosphate group of the lipid bilayer _____ faces inside the cell. faces outside the cell. faces both inside and outside the cell. lies inside the lipid bilayer. 2. Chemicals moving via passive diffusion move from higher to lower concentration. move from lower to higher concentration. require ATP for energy. move easier if polar in nature. 3. The ability of molecules to diffuse across membranes is dependent upon the chemical's oil-water partition coefficient. state of ionization. molecular weight. all of the choices 4. The extent of ionization of a chemical depends on its molecular weight. lipid solubility. pKa and the pH of the solution it is in. water solubility. 5. The blood brain barrier means that only small amounts of chemicals are in brain vessels. only a small volume of blood reaches the brain. special cells form a tight covering on the brain's capillaries. the pH of brain tissue prevents chemicals from entering. 6. The placenta prevents some chemicals from reaching the fetus by metabolizing the chemical. separating the maternal and fetal blood supplies. having a molecular weight of around 1000 daltons. all of the choices 7. Long term storage sites for chemicals in the body include liver and brain. fat and bone. liver and fat. muscle and stomach. 8. Facilitated diffusion means that energy is required. a carrier protein helps transport the chemical through the membrane. a large molecule pushes a small molecule through the membrane. two molecules go through at the same time. 9. Chemicals stored in bone may be harmful to the bone itself. when released from bone during pregnancy. when released from bone during exercise. both bone and when released from bone during pregnancy. 10. The surrounding and transport of molecules by the cell membrane is called entrapment. endocytosis. engulfment. capture and movement. Score Quiz
