細(xì)菌細(xì)胞結(jié)構(gòu)課件

1、關(guān)于細(xì)菌細(xì)胞結(jié)構(gòu)課件第一張，PPT共十五頁，創(chuàng)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). 第二張，PP

2、T共十五頁，創(chuàng)作于2022年6月（一）細(xì)胞壁cell wall:細(xì)胞壁的觀察方法： 質(zhì)壁分離染色 電鏡觀察G與G細(xì)菌cw的模式結(jié)構(gòu)共有組分 肽聚糖特有組分 G 磷壁酸 G 脂多糖細(xì)胞壁是位于菌體的外層，內(nèi)側(cè)緊貼細(xì)胞膜的一層無色透明，堅韌而有彈性的結(jié)構(gòu)。細(xì)胞壁約占細(xì)胞干重的10%25%。第三張，PPT共十五頁，創(chuàng)作于2022年6月Figure 3 - Electron micrograph of a G+ cell wall. Figure 4 - Electron micrograph of a G- cell wall. 第四張，PPT共十五頁，創(chuàng)作于2022年6月細(xì)胞壁cell wall:

3、第五張，PPT共十五頁，創(chuàng)作于2022年6月Gram Positive第六張，PPT共十五頁，創(chuàng)作于2022年6月Gram Negative第七張，PPT共十五頁，創(chuàng)作于2022年6月革蘭氏陽性菌肽聚糖單體概念：肽聚糖是由 N乙酰胞壁酸（NAM）和N乙酰葡糖胺（NAG）以及短肽鏈（主要是四肽）組成的亞單位聚合而成的大分子聚合物。（1）細(xì)胞壁的基本骨架肽聚糖（共有成分）肽聚糖網(wǎng)格狀結(jié)構(gòu)第八張，PPT共十五頁，創(chuàng)作于2022年6月第九張，PPT共十五頁，創(chuàng)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.第十張，PPT共十五頁，創(chuàng)作于2022年6月第十一張，PPT共十五頁，創(chuàng)作于2022年6月第十二張，PPT共十五頁，創(chuàng)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