1. The events in the life of a cell
CELL CYCLE
The events in the life of a cell

2. Interphase
The time between cell divisions where the cell grows to full size, duplicates its DNA and rests
Cells live a “normal” life in Interphase
Interphase is broken into three different sub-phases G1, (G0), S and G2

3. Interstate highway
BETWEEN States

4. Cell Cycle Diagram .

5. G1 Phase – (Gap) Occurs just after cell division
Cell must re-grow to normal size
Proteins are made

6. Cyklins mediate process

7. G0 Phase – Resting Phase
Most of an adult’s cells are in Interphase, stopping in G0
Cell undergoes normal cell functions while resting
A cell that skips this phase can become cancerous, growing uncontrollably
Humourous cell cycle video 3.5 mins

8. Check points
Places where cell checks itself for damage before proceeding
Cancer bypasses check points

9. S Phase - Synthesis
DNA is synthesized or copied in preparation for cell division

10. Point of no return
Once a cell enters this S phase it is committed to go through cell division
A cell must divide or self destruct upon entering

11. G2 Phase – Gap 2 Cell grows larger in preparation for cell division
Organelles, Centrosomes, enzymes and proteins are replicated

13. M Phase - Mitosis Division of cell Nucleus DNA forms into chromosomes
Chromosomes separate with identical pairs moving to opposite sides of the cell
New nuclear membrane forms around each set of chromosomes

14. Chromosomes = colored bodies
Only appear during Mitosis

15. Chromosomes Sister chromatids = identical DNA
Homologous chromosomes = same type chromosome in pairs (paternal/maternal)
Centromere – connects chromatids
Kineticore – winds up spindle fibers to separate chromatids

16. overview
24 hour cycle

17. Cell cycle animation

18. Binary Fission - Cell division in Prokaryotes
NO nucleus
No mitosis
Origen of replication is where DNA replicated first

19. Regulation of the cell cycle
Cyclin – a protein that controls the cell cycle
CDK – (Cyclin Dependant Kinase) binds to cyclin to form MPF
A Kinase is an enzyme that activates proteins
MPF – (Maturation Promoting Factor) helps start M phase

20. Formation of MPF brings past G2 checkpoint

21. Control of the Cell Cycle
Control of cell cycle you tube video

22. Growth factor
Protein released by certain body cells that stimulate other cells to divide

23. Density-dependant inhibition
Crowded cells stop dividing

24. Anchorage dependence
To divide, most cells must be attached to something

25. CANCER – Cells mutate and grow
Normally a mutant cell is destroyed or self destructs.
Called Apoptosis
This does not occur in cancer cell
Cancer cells are not inhibited by density or lack of anchorage

26. Tumors – Mass of abnormal cells
Benign tumor – remains at original site
Malignant tumor – becomes invasive and impairs function of other cells
Metastasis – The spread of cancer cells

27. Interphase (again)
Each daughter cell enters interphase, so it can regrow, rest and be a normal cell

28. Mitosis

29. Interphase The non dividing portion of the cell cycle
Most of the time a cell is in interphase

30. Prophase Chromosomes become visible Spindle fibers form
Nuclear envelope breaks down
Centrioles are replicated (Animal cells only)

31. Metaphase Chromosomes are aligned at the metaphase plate.
Polar microtubules vs. Kinetochore microtubules.

32. Anaphase
Each Kinetochore “eats” the spindle fiber and the sister chromatids are moved apart.
The polar microtubules push the poles apart.

33. Telophase The nucleus reforms The chromosomes become chromatin
Cytokinesis begins

34. CytoKinesis The complete separation of daughter cells.
Membrane sides connect

35. Cytokinesis Plant vs Animal
Animal - Cleavage furrow
Plant – Cell Plate

36. Interphase (again)
Each daughter cell enters interphase, so it can regrow, rest and be a normal cell

37. Onion cell mitosis

38. Animal cells
Interphase                                  Prophase                               Metaphase
                                                                                                                                                            
Anaphase                                 Telophase
                                                                                                    

39. Plant cells
Prophase
Anaphase
Metaphase
Interphase
Telophase

40. Metaphase
Interphase
Prophase
Cytokinesis
Anaphase
interphase