美國食品藥物管理局(FDA)以婦女懷孕用藥的安全性，將藥品分為A、B、C、D、X等5個等級如下：

A級：該類藥品傷害胎兒的可能性極小。

何謂光過敏反應（photosensitivity）?

藥物引起之光敏反應，與特異性免疫反應及藥物結構有相關性，和藥物劑量並無直接關係，

重點：

1.是線性還是非線性藥物動力學

附上公式推導過程～這是利用酵素動力學的概念去推導的
請注意下面所列出四種參數的基本關係及Km＝(k2+k3)/k1的假設！

reference：http://www.excellence.fju.edu.tw/plan/2.1.1.c/content05/html/32.htm#4.酵素降低化學反應的活化能_

Introduction to Enzymes

Enzymes are biological catalysts responsible for supporting almost all of the chemical reactions that maintain animal homeostasis. Because of their role in maintaining life processes, the assay and pharmacological regulation of enzymes have become key elements in clinical diagnosis and therapeutics. The macromolecular components of almost all enzymes are composed of protein, except for a class of RNA modifying catalysts known as ribozymes. Ribozymes are molecules of ribonucleic acid that catalyze reactions on the phosphodiester bond of other RNAs.

Enzymes are found in all tissues and fluids of the body. Intracellular enzymes catalyze the reactions of metabolic pathways. Plasma membrane enzymes regulate catalysis within cells in response to extracellular signals, and enzymes of the circulatory system are responsible for regulating the clotting of blood. Almost every significant life process is dependent on enzyme activity.

其實這是初學生化者最感困擾的問題，這兩者都是合成的意思，但何時該用哪個字，目前判斷的原則如下：

1. 若聚合的反應中涉及ATP或三磷酸核苷酸的高能鍵，則用Synthetase。