细胞核真核细胞.pptxVIP

;;细胞核（真核细胞）或拟核（细菌）：包含遗传物质DNA及其结合蛋白。 细胞核由核膜所包绕。 质膜：柔韧的脂质双层。对极性物质可选择性透过。含有发挥转运作用、信号接受和作为酶的蛋白质。 细胞的生长和分裂不会造成膜完整性的丧失。 细胞质：水溶性细胞内含物和悬浮颗粒及细胞器。 以150000r/m速度离心 上清：胞质溶胶，含有酶、RNA、单体亚单位、代谢物和无机离子的浓缩液。 沉淀：颗粒和细胞器 核糖体、贮存粒、线粒体、叶绿体、溶酶体、内质网。;a) Diameter Animal and plant cells: 5~100 μm Bacteria cells: 1~2 μm b) Cell size is limited: nucleus/cytoplasm ratio; surface area/volume ratio; substances can efficiently travel through the cytoplasm via diffusion.;;6;;原核细胞与真核细胞的基本特征比较;Prokaryotes: Archaea Eubacteria;革兰氏阴性菌;;原理 通过结晶紫初染和碘液媒染后，在细胞壁内形成了不溶于水的结晶紫与碘的复合物。 革兰氏阳性菌由于其细胞壁较厚、肽聚糖网层次较多且交联致密，故遇乙醇或丙酮脱色处理时，因失水反而使网孔缩小，再加上它不含类脂，故乙醇处理不会出现缝隙，因此能把结晶紫与碘复合物牢牢留在壁内，使其仍呈紫色； 革兰氏阴性菌因其细胞壁薄、外膜层类脂含量高、肽聚糖层薄且交联度差，在遇脱色剂后，以类脂为主的外膜迅速溶解，薄而松散的肽聚糖网不能阻挡结晶紫与碘复合物的溶出，因此通过乙醇脱色后仍呈无色，再经沙黄等红色染料复染，就使革兰氏阴性菌呈红色。 ;有机体可以根据其能量来源和合成细胞物质的碳源进行分类;Landmarks in the Evolution of Life on Earth;Evolution of Eukaryotic Cells;Eukaryotes;;;The Plasma Membrane Contains Transporters and Receptors;;Similar to lysosome, degradation Take 90% of cell volume Turgor Pressure;;Chromosome is made of DNA and protein. Basic unit: nucleosome (histone + DNA) Nucleosome ? 30nm fiber More advanced folding The overall compaction in a chromosome is greater than 10,000-fold. ;Diameter: ~1 μm 100~1000/cell Two membranes Outer: unwrinkled and completely surrounds the organelle. Inner: has infoldings, which give it a large surface area.? Principal producers of ATP Produced only by division of previously existing mitochondria Contains its own DNA, RNA, and ribosomes.;Diameter: ~5 μm Two membranes Convert solar energy into chemical energy Contains its own DNA, RNA, and ribosomes. ;;;Actin filaments: Flexible 5-9 nm diameter Concentrated near plasma membrane Microtubules: Long hollow cylinders. Rigid 25 nm diameter Attached to centrosome Intermediate filaments: Provide mechanical strength 10 nm diameter Found throughout cytoplasm;29;Actin and Tubulin Form Polar Filaments: Unequal Ends;;肌动蛋白的各个亚基聚合形成肌动蛋白纤维;Three types of cortical arrays of actin filaments.;肌球蛋白分子利用