Dr. Chen-Lu Tsou (1923-2006) obtained his doctorate from Cambridge in 1951, and became one of the founders of Chinese biochemistry. He spent most of his life on protein structure and function, making a number of original contributions. To commemorate his one hundred years of birth, two of his research achievements are elaborated in detail here, one of which is relation between the functional groups of proteins and their biological activity, and the other is on kinetics of irreversible modification of enzyme activity. This commemorative article intends to share with audiences how much can be achieved by the older generations of Chinese scientists with great minds but few resources, as epitomized in the two great pieces of work by Dr. TSOU.