有机物质直接进入水体后,通过微生物的生 物化学作用而分解为简单的无机物质二氧化碳和 水,同时在分解过程中需要消耗水中的溶解氧; 在缺氧条件下,该类污染物就发生腐败分解,恶 化水质,所以称之为需氧有机污染物

Vitamins are organic chemicals required by the body in trace amounts but which cannot be synthesized by the body. The vitamins required for growth and maintenance of health differ between species; compounds regarded as vitamins for one species may be synthesized at adequate rates by other species. For example, only primates and the guinea-pig require ascorbic acid (vitamin C; section 6.4) from their diet; other species possess the enzyme gluconolactone oxidase which is necessary for the synthesis of vitamin C from D-glucose or D-galactose

Introduction: Weathering The Breakdown of Rock At the Earth's surface, rocks are exposed to the effects of weathering: the chemical alteration and mechanical breakdown of rock, when exposed to air, moisture, and organic matter. Weathering is an integral part of the rock cycle. Weathering converts rock to regolith

Preface The BIOTOL series of texts are designed to provide a self-study resource concerning the principles, practices and applications of biotechnology. This text is designed to explain how biotechnology may be applied to solve problems encountered in the production and use of organic chemicals in a wide

Contents How to use an open learning text Preface 1 An introduction to biotechnological innovations Industry G. Mijnbeek and C. K. Leach 2 Biocatalyst in organic chemical synthesis R O. Jenkins

5.1 Introduction 5.2 Metabolic pathways and metabolic control mechanisms 5.3 The industrial production of citric acid 5.4 The production of other TCA cycle intermediates

Definition of DUB SAny abnormal uterine bleeding No specific organic cause can be found Anovulatory Hypothalamic-pituitary-ovarian axis has not fully matured

Introduction: What Is Mineral? Mineral Naturally formed, inorganic, solid material with a specific chemical composition and a characteristic crystalline structure. Rock Naturally formed, coherent mass of one or more minerals, sometimes including organic debris

HOME BACK FORWARD! PRINT SEARCH EXI INTRODUCTION Major soils of the world ORGANIC SOILS Mineral soils World Reference base for soil resources: atlas

1 An introduction to biotechnological innovations Industry G. Mijnbeek and C. K. Leach 2 Biocatalyst in organic chemical synthesis R O. Jenkins 3 Efficiency of growth and product formation R.O. Jenkins