PG-SEM-II-Physiology-2024 human physiology

cell cycle and its regulation , ppt for master degree in physiology

1. CELL CYCLE AND REGULATION
PG-SEM-II-Physiology-2024
Dr. Samiran Mondal
Assistant Professor
Rammohan College, Kolkata
28.05.2024

2. 3.Celldivision&cellcycle:Mitosisandmeiosis,theirregulation,stepsincellcycle,andcontrolofcell
cycle.
Cancer:Geneticrearrangementsinprogenitorcells,oncogenes,tumoursuppressorgenes,cancer
andthecellcycle,virus-inducedcancer,metastasis,interaction.
4.Cellsignalling:Hormonesandtheirreceptors,cellsurfacereceptor,signallingthroughG-protein
coupledreceptors,signaltransductionpathways,secondmessengers,regulationofsignalling
pathways,bacterialandplanttwo-componentsignallingsystems,bacterialchemotaxisandquorum
sensing.
5.Cellularcommunication:generalprinciplesofcellcommunication,celladhesionandrolesof
differentadhesionmolecules,gapjunctions,extracellularmatrix,integrins,neurotransmissionandits
regulation.12072MOLECULAR BIOLOGY1.GeneticElementanditsevolution
HPY-CC22-TH-P07
Cellular & Molecular Physiology
12071 CELLULAR ORGANIZATION, CELL TO CELL COMMUNICATION AND SIGNALING

3. Very important processes in all living organisms
During the cell division, DNA replication and cell growth takes place
The sequence of events by which a cell duplicates its genome, synthesizes the other constituents
of the cell and eventually divides into two daughter cells is termed as cell cycle
Rundolf Virchow suggested “ omnis cellula e cellula” means every cell is derived from pre-existing
cells.
The duration of the cell cycle varies greatly from one cell type to another cell
A single-celled yeast: divide every 90-120 mins
Mammalian liver cell: less than once a year
Muscle cells, nerve cells and RBC: do not divide
Cell cycle refers to the series of events that take place in a cell, resulting in the duplication of DNA
and division of cytoplasm and organelles to produce two daughter cells
CELL CYCLE

4. Centromere
Constriction region that divide the chromosome into two chromatids
It is the site for kinetochore assembly
Kinetochore
Site of assembly and disassembly of microtubules
Made of multiple proteins (histones like CENP-A)
Kinetochore involved in the movement of chromosomes during mitosis and meiosis
CENTROMERE AND KINETOCHORE
What is the difference between chromatin fibre and chromosome?
Chromatin
DNA coiled around histone protein
Chromatid
One half of a duplicated chromosome
Chromosome
Are two chromatids together, made of
condensed chromatin

5. CELL DIVISION IN PROKARYOTES
CELL DIVISION IN EUKARYOTES
CELL DIVISION
Divided into two main phases:
1.INTERPHASE
2.M PHASE

6. INTERPHASE
Long, metabolically active phase between two successive mitotic cell division
95% of the cell cycle is spent in interphase
G1 Phase
The period between the end of M phase and the start of DNA replication
Metabolically active and continuously grows
Increase in cell size
S Phase
Synthesis phase
DNA replication takes place
DNA per cell divides from 2C to 4C but the number of chromosome remains same i.e. 2N
In animals, centriole also divides in cytoplasm but not in plants due to the absence of centriole
G2 Phase
Gap between DNA replication and the initiation of M phase
Synthesis of proteins required for the synthesis of spindle fibres takes place
Cell growth continues
ATP synthesis increases
G0 Phase
Quiescent stage or inactive stage
Metabolically active but do not proliferate
Reversible or irreversible

7. M PHASE
Mitotic phase
Short phase
Karyokinesis (division of nucleus)
Cytokinesis (division of cytoplasm)
After M Phase the cell may enter interphase to repeat the cell division or G0 phase to arrest the cell cycle
The microtubules of the mitotic spindle separate the chromosomes
specify the position of the actomyosin contractile ring