All the answers to these questions please be as short as you can~

These questions are biologic based.

13) Many drugs are fat soluble. Why can they easily go across the membrane?Tell me why isobutyl alcohol crosses the membrane faster than methyl alcohol. Tell me why heroin crosses the membrane faster than morphine.

15) Although soluble drugs readily cross the membrane; water-soluble drugs don't. Yet there are ways around this latter issue.List three ways a water-soluble drug might get across.

5)What is the first barrier with which most drugs come into contact once they are absorbed or injected (subcutaneous, intramuscular or intraperitoneal)?

7) Discuss how the blood vessels in the kidney and brain differently impact drug distribution.

12) List five different processes for excretion. Which is most common? To be excreted by the urine, the drug must be in what form?

2) What do elements do in a covalent bond? What do they do in an ionic bond? Which is stronger?

3) What does compositional and configural complementarity mean in relation to drug binding?

10) Why is the concept of quantal dose-response functions important in understanding the effects of drugs?

12) Historically, has the brain always been thought to be important in behavior. T/F Use the perspectives in early Egypt and Greece to support your answer.