* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Cell Growth and Division
Survey
Document related concepts
Signal transduction wikipedia , lookup
Cell membrane wikipedia , lookup
Tissue engineering wikipedia , lookup
Spindle checkpoint wikipedia , lookup
Cell nucleus wikipedia , lookup
Extracellular matrix wikipedia , lookup
Endomembrane system wikipedia , lookup
Cell encapsulation wikipedia , lookup
Programmed cell death wikipedia , lookup
Cellular differentiation wikipedia , lookup
Cell culture wikipedia , lookup
Organ-on-a-chip wikipedia , lookup
Biochemical switches in the cell cycle wikipedia , lookup
Cell growth wikipedia , lookup
List of types of proteins wikipedia , lookup
Transcript
Cell Growth and Division Chapter 10 Why are cells so small? DNA – Messages from the nucleus must be able to reach all parts of the cell Diffusion – Nutrients must enter and wastes must leave – If the cell was too big, diffusion would happen too slowly Why are cells so small? Surface Area vs. Volume –As a cell grows larger, the volume increases faster than the SA –A bigger cell needs more nutrients, but has relatively less SA to take in those nutrients Surface Area vs. Volume Cell Size 5 cm 10 cm Surface Area (l×w×6) Volume (l×w×h) SA to Volume Ratio 150 cm2 600 cm2 125 cm3 1000 cm3 150/125 = 600/1000 6:5 = 6:10 Cell Cycle Cells divide before growing too large Before dividing, cells must prepare Preparation = Interphase – G1 phase: Cell grows larger – S phase: Cell makes new DNA for daughter cell – G2 phase: Cell makes new organelles for daughter cell Cell Cycle Chromosomes Each chromosome is replicated during the S phase A replicated chromosome has two identical sister chromatids connected by a centromere Centromere Sister Chromatids Mitosis Mitosis Four Stages: – Prophase (pro- means first) – Metaphase (meta- means middle/after) – Anaphase (ana- means apart) – Telophase (telo- means far away/end) Prophase Chromatin condenses into chromosomes Nuclear envelope and nucleolus disintegrate Centrioles migrate to opposite ends of the cell Spindle fibers form in foot ball shape across cell Chromosomes condensing Prophase Metaphase Chromosomes line up in the middle (equator) of the cell Spindle fibers attach to centromeres Anaphase Sister chromatids separate Spindle fibers shorten, pulling chromatids to opposite ends of cell Animal cells begin to pinch in Plant cells begin to form cell plate in the middle Anaphase Telophase Nuclear membrane built from ER around each set of chromosomes Nucleolus reforms in each nucleus Chromosomes become mass of chromatin Telophase Two cells dividing into four Cytokinesis Final division of cytoplasm resulting in two daughter cells Animals – CM pinches together Plants – Cell plate forms new CM dividing the daughter cells Plant Cell Division Which phases can you see? Anaphase Metaphase Telophase Prophase Interphase Knowing when to divide Cyclins – Protein that regulates the cell cycle in eukaryotes Internal regulators – tell the cell when to enter mitosis External regulators – control the rate of the cell cycle Cellular Response to Injury Effect of Cyclins Cytoplasm is removed from cell in mitosis Cytoplasm is injected into a second cell in G2 phase Second cell enters mitosis Cancer Cancer results when cells do not respond to cell cycle regulators Cells grow unregulated, forming a tumor Tumor damages surrounding tissue Leukemia – Blood cancer Mammary (Breast) Cancer Skin Cancer