第五章 微生物的新陈代谢95.ppt

Chapter five
Microbial metabolism
section A Heterotrophic pathways
section B Electron transport and
oxidative phosphorylation
section C Autotrophic metabolism
Section D Biosynthetic pathways
Metabolism is divided into those pathways that are degradative (catabolic) and those that are involved in synthesis. Catabolic pathways often produce energy. Microbes that anic molecules as a source of energy are called heterotrophs. Phototrophs obtain energy from light, and lithotrophs(无机营养菌) obtain energy from pounds.
Key notes (1)
Nutritional types
Metabolism in all cells is divided into catabolic (those pathways involved in breakdown anic molecules for energy and the production of pounds that may be used for synthesis) and anabolic (pathways involved in synthesis) processes.
In anisms these pathways are balanced as the energy required for anabolic processes is produced by catabolic pathways.
In mammalian cells, energy production has been maximized by the use of oxygen and thus the cell is usually well supplied with energy; however, in microbes this is not always the case.
catabolic and anabolic metabolism
Microbes can be divided into metabolic classes which relate to the sources of energy they use. The three groups are:
1. heterotrophs which anic molecules as a source of energy (these are also called anotrophs化能有机营养型);
2. phototrophs which obtain energy from light
3. lithotrophs which obtain energy from pounds.
Carbon(碳素) for cell synthesis is obtained anic molecules; however, some microbes, including the phototrophs, fix CO2.
Microbial metabolic types
Catabolism
Metabolism
anabolism
①
complex molecule simple molecules +ATP+[H]*
(Organic material ) ②
*[H] stands for reducing power (还原力)
① catabolism plex(分解代谢酶系)② anabolism plex (合成代谢酶系)
organic material
Primary energy sources (最初能源) ray irradiation(light)
Chemoheterotrophs reduced anic material
Phototrophs
chemoautotrophs
universal energy source (通用能源)——ATP
Energy metabolism
Section A