Download PPT3 - Ycmou

Online Counseling Resource
YCMOU ELearning Drive…
School of Architecture, Science and Technology
Yashwantrao Chavan Maharashtra
Open University, Nashik – 422222, India
OC-SBT082-U01-03
Introduction
Programmes and Courses
 SBT082 –CP01- Unit 01
School of Science and Technology, Online Counseling Resource…
Credits

Academic Inputs by

Arun Punaji More.
M.Sc. (Microbiology)

Experience: 11 Years

[email protected]
© 2008, YCMOU. All Rights Reserved.
3
School of Science and Technology, Online Counseling Resource…
How to Use This Resource

Counselor at each study center should use this presentation to deliver
lecture of 40-60 minutes during Face-To-Face counseling.

Discussion about students difficulties or tutorial with assignments should
follow the lecture for about 40-60 minutes.

Handouts (with 6 slides on each A4 size page) of this presentation should
be provided to each student.

Each student should discuss on the discussion forum all the terms which
could not be understood. This will improve his writing skills and enhance
knowledge level about topics, which shall be immensely useful for end
exam.

Appear several times, for all the Self-Tests, available for this course.

Student can use handouts for last minutes preparation just before end
exam.
© 2007, YCMOU. All Rights Reserved.
4
School of Science and Technology, Online Counseling Resource…
Learning Objectives

After studying this module, you should be able to:



Describe the intermediate filaments.
Describe interactions of intermediate filaments with other
proteins in forming cytoskeletons in the cells.
Describe the functions of intermediate filaments
© 2007, YCMOU. All Rights Reserved.
5
School of Science and Technology, Online Counseling Resource…
Introduction



In the formation of tissues the relative
positions of cells are fixed and have to be
maintained.
To maintain these positions in the tissue,
there must be some mechanical support to
be provided to each cell so that they would
not move from their position in the tissue.
The protein filaments which provide these
mechanical strength and support to each
cell in the tissue are intermediate filaments.
© 2007, YCMOU. All Rights Reserved.
6
School of Science and Technology, Online Counseling Resource…
Intermediate Filaments-1



These types of filaments are of dimension
which lie in between the dimensions of
actin and microtubule filaments; therefore
they are called as intermediate filaments.
The intermediate filaments have diameter
of 10nm.
Intermediate filaments are made of with
variety types of proteins.
© 2007, YCMOU. All Rights Reserved.
7
School of Science and Technology, Online Counseling Resource…
Intermediate Filaments-2

Types of proteins of intermediate
filaments:





Acidic keratins, ---type I
Basic keratins, ----type II
Vimentin, ----------type III
Neurofilament proteins, --------type IV
Nuclear lamins ------------type V
Nestins --------------------type VI
© 2007, YCMOU. All Rights Reserved.
8
School of Science and Technology, Online Counseling Resource…
Intermediate Filaments-3



The intermediate filaments are grouped
on the basis of these types of proteins
from which they are made of with.
For example type I and type II are made
of with acidic keratins and basic keratins.
Type I and type II intermediate filaments
are most abundant in cytoplasm of
epithelial cells.
© 2007, YCMOU. All Rights Reserved.
9
School of Science and Technology, Online Counseling Resource…
Structure of Intermediate Filaments




All the intermediate filaments are alpha
helical polypeptide chain made of with 310
to 350 amino acids.
The N-terminal of this polypeptide chain is
called as head.
The C-terminal of this polypeptide chain is
called as tail.
Unlike the actin and microtubule filaments,
intermediate filaments are non polar,
namely they do not have + and - ends.
© 2007, YCMOU. All Rights Reserved.
10
School of Science and Technology, Online Counseling Resource…
Structure of Intermediate Filament

Structure of intermediate filament:
Steps in the formation of intermediate
filament.
© 2007, YCMOU. All Rights Reserved.
11
School of Science and Technology, Online Counseling Resource…
Characteristics of Intermediate Filament



The intermediate filaments are more
stable than actin and microtubule
filaments.
They are not dynamic like actin ant
microtubule filaments.
Within cells they are frequently modified
by assembly and disassembly by the
process of phosphorylation.
© 2007, YCMOU. All Rights Reserved.
12
School of Science and Technology, Online Counseling Resource…
Functions of Intermediate Filament



For example the phosphorylation of
nuclear lamins results into disassembly of
nuclear lamins and finally breakdown of
nuclear membrane in mitosis.
The intermediate filaments provide
mechanical stability to tissues.
For example the keratin filaments are
firmly anchored into the special region of
plasma membrane known as desmosomes
and hemidesmosomes.
© 2007, YCMOU. All Rights Reserved.
13
School of Science and Technology, Online Counseling Resource…
Functions of Intermediate Filament-2

In the epithelial cells of epithelial layer,
the keratin filaments anchored to the both
sides of desmosomes of adjacent cells
forming a mechanical links between the
adjacent cells in epithelial layer providing
mechanical stability to the tissue.
© 2007, YCMOU. All Rights Reserved.
14
School of Science and Technology, Online Counseling Resource…
Functions of Intermediate Filament-3

The intermediate filaments, desmin, in
muscle tissues connect the individual
actin-myosin assemblies both to one
another and to plasma membrane,
collectively enhancing the action of
individual contractile desmin bundles.
© 2007, YCMOU. All Rights Reserved.
15
School of Science and Technology, Online Counseling Resource…
Functions of Intermediate Filament-4

The neurofilaments which are major
intermediate filaments in matured neuron
provides support and stabilize the other
types of cytoskeleton filaments in the
delicate long thin axons of nerve cells.
© 2007, YCMOU. All Rights Reserved.
16
School of Science and Technology, Online Counseling Resource…
Critical Thinking Questions

What role the intermediate filaments play
in the cell division?
© 2008, YCMOU. All Rights Reserved.
17
School of Science and Technology, Online Counseling Resource…
Hints for Critical Thinking Questions

They are present in the nuclear
membrane.
© 2008, YCMOU. All Rights Reserved.
18
School of Science and Technology, Online Counseling Resource…
Study Tips

Book




Title: The Cell, A Molecular Approach
Author: Geoffrey M. Cooper, Robert E. Hausman
Publication: ASM press, Washington,D.C.
Book



Title: Cell and Molecular Biology
Author: E.D.P. De Robertis and E.M.F. De Robertis, Jr.
Publication: Lippincott and Williams & Wilkins
© 2008, YCMOU. All Rights Reserved.
19
End of the Presentation
Thank You !