chronous in cell growth and at the same stages of cell cle thus the individual biochemical changes can be Ways to keep synchronous growth Induced by the environmental condition(环境条件诱导法) 2. Mechanically screening(机械筛选法)
Synchronous culture trying to keep a group of cells synchronous in cell growth and at the same stages of cell cycle , thus the individual biochemical changes can be indirectly studied through the group. Ways to keep synchronous growth: 1. Induced by the environmental condition(环境条件诱导法) 2. Mechanically screening (机械筛选法)
Cell cycle The sequence of events extending from the formation of a new cell to the next division is called the cell cvcle. (H ROB U 指从一个细胞分裂结束到第二次新的细胞分 经历的顺序事件 In this cycle, a growing E. coli will double in length then divide into two cells of equal ith each new cell containing at least one copy of the bacterial DNA onsequently. during this time, a copy of the chromosome nust be synthesized and the two chromosomes segregated into he two daughter cells
The sequence of events extending from the formation of a new cell to the next division is called the cell cycle.(细胞周期是 指从一个细胞分裂结束到第二次新的细胞分裂结束所经历的顺序事件) In this cycle, a growing E. coli will double in length then divide into two cells of equal size, with each new cell containing at least one copy of the bacterial DNA. Consequently, during this time, a copy of the chromosome must be synthesized and the two chromosomes segregated into the two daughter cells. Cell cycle
DNA replication DNA replication occurs during the C(chromosome replication) phase and chromosome segregation(2) occurs in the G(gap) phase, which may be of variable length. Segregation of the chromosomes is achieved by attachment of the replicated DNA onto two adjacent sites on the membrane Membrane growth between the sites pushes the chromosomes towards the poles of the cells Finally, a cross wall(septum) Is laid down between the two chromosomes and the cell divides into two (D phase)
DNA replication occurs during the C (chromosome replication) phase and chromosome segregation（分离） occurs in the G (gap) phase, which may be of variable length . Segregation of the chromosomes is achieved by attachment of the replicated DNA onto two adjacent sites on the membrane. Membrane growth between the sites pushes the chromosomes towards the poles of the cells. Finally, a cross wall (septum) is laid down between the two chromosomes and the cell divides into two (D phase). DNA replication
Coordinated replication and division Cell division and DNA replication have to be coordinated (y) Initiation of DNA replication at the origin oriC),a short adenine and thymine rich sequence, Is dependent on the cell reaching a critical mass( initiation mass)(DNA复制取决于 细胞中起始物质所达到的临界量(准备DAN复制相关的酶和蛋白)) and requires a number of protein initiation factors. DNA segregation and division, however, are controlled by the length of the cell which must reach a particular threshold length(pi i) before the chromosomes are partitioned and cell division initiated
Cell division and DNA replication have to be coordinated. （协调） Initiation of DNA replication at the origin (oriC), a short adenine and thymine rich sequence, is dependent on the cell reaching a critical mass (initiation mass)（DNA复制取决于 细胞中起始物质所达到的临界量（准备DAN 复制相关的酶和蛋白）） and requires a number of protein initiation factors. DNA segregation and division, however, are controlled by the length of the cell which must reach a particular threshold length（阈值） before the chromosomes are partitioned and cell division initiated. Coordimated replication and division
Chromosome replication Variable Division Fig. Stages in the cell cycle of prokaryotes
Fig. Stages in the cell cycle of prokayotes