Enzyme unit many kinds of substance besides enzymes (for example, vitamins and hormones). Enzyme unit The enzyme unit (symbol U or sometimes EU) is a unit for the amount of a particular enzyme. One U is defined as the amount of the enzyme that produces a certain amount of enzymatic activity, that is, the amount that catalyzes the conversion of 1 micro-mole of substrate per minute. The conditions also have to be specified: one usually takes a temperature of 25°C and the pH value and substrate concentration that yield the maximal substrate conversion rate. The enzyme unit was adopted by the International
Si River to the large amount of silt carried by the river, it left behind a high layer of mud in the lower reaches of the Si River’s former course. The philosopher Confucius is buried on the north bank of the Si River where it passes through Qufu City. The river was also traditionally regarded as a place where the Nine Cauldrons were lost. Si River The Si River is a river in Shandong Province, China. It also ran through the area of modern Jiangsu Province until floods in 1194. The Si rises in the southern foothills of the Mengshan Mountains (蒙山),