Assay:化验,分析,测定。 Enzyme activity: unit() is defined as the amount of enzyme which convert 1 micromole (umol) of substrate to product(s) in 1 minute under specified conditions. Specific activity: enzyme activity expressed per unit mass of protein present. (units/mg)
1. Living matter is composed mostly of the lighter elements 1.1 The composition of living matter is strikingly different from that of its physical environment(1810s) 1.2 The elements found in living organisms also exist in nature(especially in seawater and atmosphere)