| Popis: |
This chapter provides an overview of how the microorganisms fulfill their nutritional needs and how they extract energy to carry out their life metabolic processes. A heterotrophic bacterium that can grow in a medium containing only glucose as the carbon and energy source, ammonium sulphate as the nitrogen and sulphur source, and a few additional inorganic compounds, has great biosynthetic capability. From these nutritional substances, the microbe can synthesize nitrogenous substances, carbohydrates, and phospholipids. In synthesizing the polysaccharides from monosaccharides, a cell cannot simply glue sugars together. Energy is required to establish the necessary covalent linkages. This energy is in the form of ATP and is expended only inside the cell to energize the monosaccharides. The biosynthesis of the bacterial cell wall peptidoglycan is an endergonic process. It is highly complex and the resulting macromolecule is a rigid cross-linked material that maintains the shape of the bacterial cell. |
