Hầu hết đã có kinh nghiệm tìm kiếm thông qua một kính hiển vi ở một tế bào duy nhất. Nó có thể có được một amip, sống và chảy về giống như một blob của thạch trên kính hiển vi, hoặc một tế bào của vi khuẩn, dính với một loại thuốc nhuộm để làm cho nó hiển thị rõ ràng hơn. Hoặc nó có thể có được một tế bào tảo đẹp với chất diệp lục màu xanh lá cây tươi sáng của nó. Ngay cả những đơn giản nhất của các tế bào này có khả năng. | Chapter 3 Biochemistry biochemistry Most people have had the experience of looking through a microscope at a single cell. It may have been an amoeba alive and oozing about like a blob of jelly on the microscope slide or a cell of bacteria stained with a dye to make it show up more plainly. Or it may have been a beautiful cell of algae with its bright green chlorophyll. Even the simplest of these cells is capable of carrying out a thousand or more chemical reactions. These life processes fall under the heading of biochemistry the branch of chemistry that deals with the chemical properties composition and biologically mediated processes of complex substances in living systems. Biochemical phenomena that occur in living organisms are extremely sophisticated. In the human body complex metabolic processes break down a variety of food materials to simpler chemicals yielding energy and the raw materials to build body constituents such as muscle blood and brain tissue. Impressive as this may be consider a humble microscopic cell of photosynthetic cyanobacteria only about a micrometer in size which requires only a few simple inorganic chemicals and sunlight for its existence. This cell uses sunlight energy to convert carbon from CO2 hydrogen and oxygen from H2O nitrogen from NO- sulfur from SO4 and phosphorus from inorganic phosphate into all the proteins nucleic acids carbohydrates and other materials that it requires to exist and reproduce. Such a simple cell accomplishes what could not be done by human endeavors even in a vast chemical factory costing billions of dollars. Ultimately most environmental pollutants and hazardous substances are of concern because of their effects on living organisms. The study of the adverse effects of substances on life processes requires some basic knowledge of biochemistry. Biochemistry is discussed in this chapter with an emphasis on the aspects that are especially pertinent to environmentally hazardous and toxic substances including
