Rohit kumar ppt hnb garhwal university uttarakhand

1. HEMVATI NANDAN BAHUGUNA GARHWAL
UNIVERSITY SRT CAMPUS (TEHRI GARHWAL)
DEPARTMENT OF ZOOLOGY
NAME OF PAPER: CELL BIOLOGY & MOLECULAR BIOLOGY
TOPIC: CYTOSKLETON
SUBMITTED BY :ROHIT KUMAR
M.Sc. ZOOLOGY 1ST SEM
SUBMITTED TO: PROF. Dr. N.K. AGGRAWAL
ROLL NO: 29
SESSION : 2022-23

2. CYTOSKELETON
• KEYWORDS:
oINTODUCTION
oTYPES OF CYTOSKELETON
oMICROTUBULE FILAMENTS
 TUBULIN (Main protein of Microtubule)
oMICROFILAMENTS
 ACTIN (Main protein of Microfilament )
oINTERMEDIATE FILAMENTS

3. INTRODUCTION
What is Cytoskeleton?
It is a complex network of filaments and microtubules which
forms a structural framework.
Skeleton and muscle of the cell.
Responsible for segregation of chromosome into two daughter
cell at cell division.

4. TYPES OF CYTOSKELETON
• The cytoskeleton is built on a framework of three types
of proteins filaments:
• Microtubules(Made of tubulin protein)
• Microfilaments(Network of the actin filament)
• Intermediate Filaments
(These cellular structures are collectively called “Cytoskeleton”)

5. MICROTUBULES
 Long hollow cylinders made up of tubulin.
Provide internal shape and support to the cell.
Also involve in nucleic and cell division.
Two types of tubulin are found alpha tubulin and beta tubulin.

6. TUBULIN (Protein Of Microtubule)
Microtubules are composed of protein sub-units called tubulin.
Term tubulin is used for principal protein for Cilia & Flagella.
One dimer of tubulin binds to molecule of 3H-colchine
Tubulin has kinase and ATPase activity.

7. CILIA AND FLAGELLA
• Cilia and Flagella are hair like structure.
• Made up of microtubules and covered by extension of plasma
membrane.
• They create current for obtaining food from aquatic medium.
• They move liquid past surface of the cell.
9+2 Arrangement

8. MICROFILAMENTS
• Thinnest class of the cytoskeletal fibres.
• Solid rods of globular protein Actin.
• Actin filament present throughout the cytoplasm of Eukaryotic
cell.
• Responsible for movement , especially involving cell surface.
• Can also from structures like microvilli.

9. MOVEMENT BY ACTIN FILAMENT
• Cell pushes out protrusions at its leading edge.
• Then these protrusions adhere to the surface.
• Rest of the cell drags itself forward on these anchorage points.

10. MUSCLE CONTRACTION
• Actin filament is double stranded F- actin protein molecule.
• Tropomyosin molecule are wrapped spirally around the sides of
F-actin helix.
• Troponin are usually complexes of three loosely bound protein
subunits .
• Myosin head function as an ATPase enzyme.
• This property allows the head to cleave ATP.

11. INTERMEDIATE FILAMENT
• Different cell types, different intermediate filaments.
• Resist stresses applied externally to the cytoplasm.
• Made up of fibrous intermediate proteins.
• Composed of two anti-parallel dimer.
• TYPES OF FILAMENTS:
• Keratin filaments
• Vimentin filaments
• Nuclear lamnins
• Neuro filaments

12. SUMMARY
• The cytoskeleton organizes the structures and activities of the
cell.
• The cytoskeleton also plays a major role in cell motility.
• There are three main types of fibres in the cytoskeleton:
Microtubules, Microfilaments and Intermediate filaments.
REFERENCE
• Cell and Molecular Biology( E.D.P. De Robertis, E.M.F. De
Robertis,Jr);Eighth Edition (2011)