细菌细胞结构课件

1、关于细菌细胞结构课件第一张，PPT共十五页，创作于2022年6月Figure 1. Schematic diagram of a typical procaryotic cell. Minimally, a procaryote is composed of a cell wall and plasma membrane that surrounds its cytoplasm containing a chromosome, ribosomes, enzymes, several classes of RNA, and small molecules (precursors). 第二张，PP

2、T共十五页，创作于2022年6月（一）细胞壁cell wall:细胞壁的观察方法： 质壁分离染色 电镜观察G与G细菌cw的模式结构共有组分 肽聚糖特有组分 G 磷壁酸 G 脂多糖细胞壁是位于菌体的外层，内侧紧贴细胞膜的一层无色透明，坚韧而有弹性的结构。细胞壁约占细胞干重的10%25%。第三张，PPT共十五页，创作于2022年6月Figure 3 - Electron micrograph of a G+ cell wall. Figure 4 - Electron micrograph of a G- cell wall. 第四张，PPT共十五页，创作于2022年6月细胞壁cell wall:

3、第五张，PPT共十五页，创作于2022年6月Gram Positive第六张，PPT共十五页，创作于2022年6月Gram Negative第七张，PPT共十五页，创作于2022年6月革兰氏阳性菌肽聚糖单体概念：肽聚糖是由 N乙酰胞壁酸（NAM）和N乙酰葡糖胺（NAG）以及短肽链（主要是四肽）组成的亚单位聚合而成的大分子聚合物。（1）细胞壁的基本骨架肽聚糖（共有成分）肽聚糖网格状结构第八张，PPT共十五页，创作于2022年6月第九张，PPT共十五页，创作于2022年6月Figure 5 - A comparison of L and D amino acids. Note that while

4、 the structure is identical, it is impossible to superimpose them.第十张，PPT共十五页，创作于2022年6月第十一张，PPT共十五页，创作于2022年6月第十二张，PPT共十五页，创作于2022年6月Figure 8. Schematic diagram of the peptidoglycan sheet of Staphylococcus aureus. G = N-acetyl-glucosamine; M = N-acetyl-muramic acid; L-ala = L-alanine; D-ala = D-ala

5、nine; D-glu = D-glutamic acid; L-lys = L-lysine. This is one type of murein found in Gram-positive bacteria. Compared to the E. coli peptidoglycan (Figure 7) there is L-lys in place of DAP (diaminopimelic acid) in the tetrapeptide. The free amino group of L-lys is substituted with a glycine pentapep

6、tide (gly-gly-gly-gly-gly-) which then becomes an interpeptide bridge forming a link with a carboxy group from D-ala in an adjacent tetrapeptide side chain. Gram-positive peptidoglycans differ from species to species, mainly in regards to the amino acids in the third position of the tetrapeptide side chain and in the amino acid composition of the