tailieunhanh - Enzymes in the Environment: Activity, Ecology and Applications - Chapter 21 (end)

Phản ứng trong môi trường liên quan đến quá trình hóa học, sinh hóa, và thể chất. Nó cũng được biết rằng hầu hết các phản ứng sinh hóa được xúc tác bởi enzyme, protein có tính chất xúc tác. Chất xúc tác là những chất đó, mà không cần trải qua thay đổi vĩnh viễn, gây ra phản ứng hóa học để tiến hành với tốc độ nhanh hơn. Ngoài ra, các enzyme cụ thể cho các loại phản ứng hóa học mà họ tham gia. Tất cả các hệ thống sống, khác nhau, từ vi khuẩn đến vương. | 21 Enzymes in Soil Research and Developments in Measuring Activities M. Ali Tabatabai Iowa State University Ames Iowa Warren A. Dick The Ohio State University Wooster Ohio I. INTRODUCTION Reactions in the environment involve chemical biochemical and physical processes. It is well known that most biochemical reactions are catalyzed by enzymes which are proteins with catalytic properties. Catalysts are substances that without undergoing permanent alteration cause chemical reaction to proceed at faster rates. In addition enzymes are specific for the type of chemical reactions in which they participate. All living systems ranging from bacteria to the animal kingdom from algae and molds to the higher plants contain a vast number of enzymes catalyzing both simple and complex networks of chemical reactions. Enzymes also are found in ponds lakes rivers water treatment plants animal manures and soils and exist either as extracellular forms separated from their origins or as intracellular forms as part of the living biomass. These enzymes are involved in the synthesis of proteins carbohydrates nucleic acids and other components of living systems and also in the degradation and essential cycling of carbon nitrogen phosphorus sulfur and other nutrients. The study of enzymes in general is a subject of interest to many disciplines ranging from biology to the physical sciences. This is not surprising as enzymes have a central place in biology and life depends on a complex network of chemical reactions facilitated by specific enzymes. Any alterations in the enzyme protein structures might have far-reaching consequences for the living organism. It is safe to say that soils would remain lifeless and basically unaltered without enzymatic reactions. Within the past five decades enzymology the science of studying enzymes has developed rapidly. This field of science has connections with many other sciences and has contributed to our understanding of microbiology biochemistry molecular .