Cell cycle and regulation

Cell cycle and Regulation
* cell Division is occur in every human but these have certaint check point to preventing from the forming the defective cell or cancerious cell.

1. CELL CYCLE AND REGULATION
GuidedBy:P.G.Jain Presentedby:ShubhamD.Mahajan
I
st
YearMPharmacy
DepartmentOfPhrmacology
Mr.Tushar D. Morankar 1

2. Content
•Introduction
•Phases
•Regulation
Mr.TusharD. Morankar
Mr.Tushar D. Morankar 2

3. Cell Cycle And It’s Regulation
Defination…
The period between two cell division is known as cell cycle.
➢Repair body tissue
It consist of two stages
➢1)Interphase
➢2)Mitosis
Mr.Tushar D. Morankar 3

4. ➢Interphase :
Three types of cell cycle
1)G1 phase
2)S phase
3)G2 phase
1) G1 Phase
(Post –mitotic phase)
▪It is a longest phase
▪It take place at the end of cell division
▪Prepare for DNA synthesis
▪Active synthesis of RNA and protein takeplace
▪The newly formed cell accumulate the energy
Mr.Tushar D. Morankar 4

5. G0 Phase
▪It is a resting phase
▪In these cell cyclinD concentration is decreased
▪Hold the cell cycle at checkpoint 1 by inhibiting the expression of several
transcription protein (E2F) that code cyclinA and E necessary for cycle
progression
▪Growth factor stimulation take the G0 cells to G1 phase
▪In interphasethe cell prepare itself to check the term post-mitotic is sometime
used to refer both quiescent G0 state from G1 and may remain quiescent for
longer period of time or indefinitely (eg. Cardiac and neuron cell )
▪In multicellulareukaryotes cell enter the G0 phase from G1 phase and stop
dividing
▪Some cell enter the G0 phase semipermanently(eg. Liver and kidney)
Mr.Tushar D. Morankar 5

6. 3) S Phase
(Synthesis phase)
▪In that phase the DNA replication can proceed through the mechanism that result
in the formation of identical pairs of DNA molecule –sister chromatid –that are
fimelyattached to the centromeric region.
▪The centrosome is duplicated during S phase.
4) G2 Phase
(Invisible phase)
▪RNA synthesis and protein macromolecule.
▪The cell replineshesits energy store and synthesizes protein necessary for
chromosome manipulation .
▪There may be additional cell growth during G2
▪The final preparation for the mitotic must be completed before the cell is able to
enter the first stage of mitosis. Mr.Tushar D. Morankar 6

7. ❑Prophase
•Chromosome composed of 2 identical (sister) chromatid
•Nuclear envelop disappear
•Centromere divided together but remain together
•Spindle fibre begin to grow from centrosome
Mitosis :
Mitosis phase follow interphase
It divided into four phase :
❑Prophase
❑Metaphase
❑Anaphase
❑Telophase
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8. ❑Metaphase
•Chromosome move to the equator of the cell (metaphase plate)
•Spindle fibre become attached to the sister chromatid
•Spindle apparatus is complete
❑Anaphase
•Sister chromatid begin to separate
•Each chromatid migrate end of the cell at opposite site
Mr.Tushar D. Morankar 8

9. ❑Telophase
•Sister chromatid arrive at opposite pole
•Mitotic spindle disappear
•uncoil of DNA
•cytokinesis
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10. Mr.Tushar D. Morankar 10

11. Cell cycle regulation
Three types of checkpoint
➢G1 checkpoint
➢G2 checkpoint
➢M checkpoint
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12. REGULATOR MOLECULE OF THE CELL
Two type of intracellular molecule regulated by
❑Positive regulation
❖Are those which control the changes necessary for cell division
❖They include :
–Cyclin
–Cdks
❖Responsible for progress of cell through various check point
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13. •Protein kinase are enzyme that phosphorylate protein .
•The transition from G1 to S require set of cyclin and different transition
require different cyclin .
•Cdks posses two type of phosphorylation site : one cause activation of the
enzyme ;the other causes inactivation of the enzyme .
•Specific kinase carry out the stimulatory and the inhibitory phosphorylation.
•similarly Protein phosphatase can remove phosphate from CDKs ,either
stimulating or inhibiting their activity ,depending on the position of the
phosphate
•the addition or removal of phosphate group from CDKs is highly regulated
and an important mechanism for the control of cell progession
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14. FOUR CLASS OF CYCLIN
1.G1-cyclin: helps to promote passage through ‘start’ or the restriction point in late G1
2.G1/S-cyclin: bind cdksthe end of G1 and commit the cell to DNA replication
3.S-cyclin: bind cdksduring S phase and required for the initiation of DNA replication
4.M-cyclin: promote the event of mitosis.
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15. ❑Negative regulation
❖Halt the cell cycle
❖Regulator eg. Rb, p53 and p21
❖Rb–tumor suppressor protein
❖Designation on function molecular mass in (Kd)
❖Rbprimarily act on G1 checkpint.
❖P53 and p21 accumulate
❖Rbmonitor cell size
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16. Mr.Tushar D. Morankar 16

17. REFERENCES..
❑Anne Waugh, Allison grant, “Ross and Wilson, Anatomy and physiology in health and Illness”12
th
edition and sons,Inc.
❑www.OpenStax.com
❑www.wikipedia.com
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