Cell Cycle and Its Regulation modified.pptx

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1. Cell Cycle and Its Regulation Presented by:- K. HEISIYILE ROLL NO. -18 MSC 1 st SEMESTER DHANAMANJURI UNIVERSITY Department of Zoology

2. CONTENTS Introduction Phases of cell cycle. Regulatory molecule of the cell cycle Reference

3. Introduction The cell cycle is a series of events that lead to cell division and duplication. It consists of interphase (G1, S, G2) and mitotic phase (M). Regulation is crucial to prevent uncontrolled cell growth (e.g., cancer). Key regulators include cyclins, cyclin-dependent kinases (CDKs), and checkpoint proteins.

4. 1) INTERPHASE Three sub-phases of cell cycle G1 phase S phase G2 phase I) GI Phase (Post —mitotic phase ) It is a longest phase It take place at the end of cell division Prepare for DNA synthesis

5. 2) S Phase(Synthesis phase) S phase, or synthesis phase, is the phase of the cell cycle when DNA is copied . It occurs between the G1 and G2 phases.   • The DNA molecule is unwound by an enzyme called helicase. • The two single DNA strands are used as templates to form two identical double DNA strands. • An enzyme called DNA polymerase binds nucleotides to each of the single template DNA strands. • Each chromosome now consists of two sister chromatids. 3) G2 Phase (Invisible phase) RNA synthesis and protein macromolecule. The cell replenishes its 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.

6. Regulatory molecule of the cell cycle It includes cyclin, cyclin dependent kinases(CDKs) and checkpoints integrate intracellular and extracellular signals. Cyclin :- Protein whose level fluctuate throughout the cell cycle, binding to CDKs CDK :- Enzymes that are only active when bound to cyclin, allowing them to phosphorylate and activate other protein for cell cycle progression.

7. REFERENCE Textbook The Cell A Molecular Approach , Geoffrey M. Cooper. The Molecular Biology of The Cell , Bruce Alberts, Rebecca Heald, Alexander Johnson, David Morgan, Martin Raff, Keith Roberts Peter Walter. Thank you