cell division n.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
Cell Division PowerPoint Presentation
Download Presentation
Cell Division

Loading in 2 Seconds...

  share
play fullscreen
1 / 27
dylan-williamson

Cell Division - PowerPoint PPT Presentation

113 Views
Download Presentation
Cell Division
An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

  1. CellDivision Cell divides into two daughter cells Revised 10-09-2006

  2. Cell Cycle • G1 phase • Cellular Growth • Development • S phase • DNA Replication • Protein synthesis • G2 phase • Synthesis of organelles • Materials for cell division • M Phase • Mitosis

  3. Length of the Cell Cycle • Intestine • 24-48 hours • Frog embryo • 1 hour

  4. Control of the Cell Cycle • Cyclins • Cyclin Dependent Kinases

  5. Cell Cycle Regulation The cyclins are named “cyclins” because their appearance during the cell cycle is cyclical

  6. Cyclins/Kinases Complexes

  7. G1 phaseCellular Growth and Development Cyclin D CDK4 CDK6 Cyclin E CDK 2 • Checkpoint 1 • Cell size? • DNA?

  8. Cyclin D

  9. cyclin D-dependent kinase Cdk6

  10. S phase DNA Replication and Protein synthesis Cyclin A CDK 2

  11. Cyclin A • Residues 173-432 • 2 similar domains • Cyclin fold • 5 α-helices

  12. CDK 2 • Domain 1 • 85 residues • 1 α-helix • 5 stranded β-sheet • Domain 2 • 213 residues • α-helices

  13. Cyclin A/CDK 2 Complex

  14. Cyclin A/CDK 2 Complex Inactive Active

  15. G2 • Checkpoint 2 • All DNA Duplicated? • Cell size? • All DNA Intact? • Repair DNA • Cyclin B

  16. Cell Cycle Regulation M-phase promoting Factor MPF • Checkpoint 3 • Chromosomes attached to spindle fibers?

  17. Mitosis • Process by which the nucleus of the cell is divided into two nuclei, each with the same number and kinds of chromosomes as the parent cell. • Cytokinesis is the process by which the cytoplasm is divided. .

  18. Chromosomes

  19. Prophase Longest (50 - 60%) • Appearance of chromosomes • Nucleolus disappears • Nuclear membrane breaks down • Centrioles separate and migrate to opposite poles of cell

  20. Metaphase Shortest • Chromosomes line up across center of cell • Spindle fibers form from centrioles to centromere

  21. Anaphase • Sister Chromatids split at Centromere • Individual Chromosomes move toward poles

  22. Telophase Final Phase • Spindle fibers breakdown • Chromosomes uncoil into Chromatin • Nuclear envelope reforms • Nucleolus becomes visible

  23. Mitosis in Whitefish and Onion PROPHASE METAPHASE ANAPHASE TELOPHASE

  24. Cytokinesis The process by which the cytoplasm divides, forming two new cells.

  25. Cytokinesis The process by which the cytoplasm divides, forming two new cells. • Animals • Cell membrane • pinches inward • Plants • Cell plate

  26. Result of Cell Division Two cells that are identical to each other.