o Different cell cycle length Some eukaryotic cell cycle times Cell Type Cell-Cycle Times Early frog embryo cells 30 minutes Yeast cells 1.5-3 hours Intestinal epithelial cells 12 hours Mammalian fibroblasts in culture -20 hours Human liver cells I year The greatest variation occurs in the duration of GI The shortest eukaryotic division cycles of all are the early embryonic cell cycles, no G and g2
❖ Different cell cycle length Some eukaryotic cell cycle times The greatest variation occurs in the duration of G1 The shortest eukaryotic division cycles of all are the early embryonic cell cycles, no G1 and G2
Biochemical events of cell cycle GI phase: Synthesize proteins(RNA) for the dNa replication. Uncondense chromatin sphase: Synthesis of DNa and histones G2 2 phase: Synthesis of a few proteins(rna) M phase: Mitosis and meiosis and cytokinesis Chromosome condense Mitotic spindle Contractile ring Two daughter cells
❖ Biochemical events of cell cycle G1 phase: Synthesize proteins (RNA) for the DNA replication. Uncondense chromatin. S phase: Synthesis of DNA and Histones G2 phase: Synthesis of a few proteins (RNA) M phase: Mitosis and meiosis and cytokinesis Two daughter cells Chromosome condense Mitotic spindle Contractile ring
M PHASE mitosis Inuclear division cytokinesis G PHASE (cytoplasmic divisionl INTERPHASE G G PHASE S PHASE (DNA replication OVERVEW OF THE CELL CYCLE
Three categories of cells in vivo (1)Cycling cells Dividing continuously--Stem cells ②2) Go cells appropriate stimulus: liver cells, lymphocyte en an Do not divide normally, but divide when gi 3 Terminally Differentiated cells Highly specialized, have lost the ability to divide until they die: muscle cells, red blood cells, nerve cells
❖ Three categories of cells in vivo (1)Cycling cells Dividing continuously—Stem cells (2) G0 cells Do not divide normally, but divide when given an appropriate stimulus: liver cells, lymphocytes (3) Terminally Differentiated cells Highly specialized, have lost the ability to divide until they die: muscle cells, red blood cells, nerve cells
Embryo cells Cycling GO Terminal cels cells cels
Embryo cells Cycling cells G0 cells Terminal cells