Plasma membrane dynamic structure By KK Sahu Sir

Introduction

History
Definition
Structure of plasma membrane(fluid mosaic model)
Examples to show dynamic nature of plasma membrane
The diffusion of membrane protein after fusion
Restriction on protein and mobility
Control of membrane protein and mobility
Membrane lipid mobility
Membrane domains and cell polarity

Function of plasma membrane

Conclusion.
References.

1. DYNAMIC STRUCTURE OF PLASMA MEMBRANE ) By KAUSHAL KUMAR SAHU Assistant Professor (Ad Hoc) Department of Biotechnology Govt. Digvijay Autonomous P. G. College Raj-Nandgaon ( C. G. )

2. SYNOPSIS Introduction History Definition Structure of plasma membrane(fluid mosaic model) Examples to show dynamic nature of plasma membrane The diffusion of membrane protein after fusion Restriction on protein and mobility Control of membrane protein and mobility Membrane lipid mobility Membrane domains and cell polarity Function of plasma membrane Conclusion. References.

3. INTRODUCTION The cell is the basic structural functional and biological unit of all known living organism. Membranes are usually from 60 to 100 A thick . They are dynamic in nature any injured part of the membrane is repaired with no time.

4. HISTORY The plasma membrane was discovered by Schwann 1838. The term cell membrane was used by c.nageli and c.cramer was 1855. The same was named “plasma lemma” was given by j.o. plower 1931.

5. DEFINATION Cell membrane is outer layer of protoplasm which control ionic concentration between protoplasm and atmosphere.

6. STRUCTURE OF PLASMA MEMBRANE (Fluid mosaic model ) The essential feature of the fluid mosaic model is that biological membrane considered to be classified structure in which the lipid and integral protein are arranged in mosaic manner . The fluid mosaic model of Singer & Nicolson is now widely.

7. HYDROPHOBIC INTERACTION

8. THE DYNAMIC NATURE OF PLASMA MEMBRANE Lipid bilayer can exit in a relatively fluid state. Lipid provide the matrix in which integral proteins of a membrane are embedded the physical state of the lipid is an important determinant of the mobility of integral protein.

9. STRUCTURE

10. 1)EXAMPLE TO SHOW DYNAMIC NATURE OF OF MEMBRANE PROTEIN Cell fusion is a technique where by two different types of or cells from two different species can be fused to produce one cell with a common cytoplasm and a single continuous plasma membrane . The first experiments to demonstrate that membrane proteins could move within the plane of the membrane utilized cell fusion and they were reported in 1970 by Larry Frye and Michel deaden of Johns Hopkins univer sity.

11. EXAMPLE TO SHOW DYNAMIC NATURE OF PLASMA MEMBRANE PROTEIN In their experiments mouse and human cells were fused and the locations of specific protein of the plasma membrane followed once the two membranes had become continuous . These early cell fusion experiments gave impression that integral membrane proteins were capable of virtually unrestricted movements .

12. STRUCTURE OF CELL FUSION

13. RESTRICTION ON PROTEIN AND LIPID MOBILITY Several techniques allow researchers to follow the movements of molecules in the membranes of living cell using the light minerals in a fluorescence recovery after photo bleaching

14. 2)RESTRICTION ON PROTEIN AND LIPID MOBILITY In single particle tracking individual membrane protein molecules are labeled usally with antibody coated gold particle (approximately 40nm in diameter) and the movements of the labeled molecules are followed by computer enhanced video microscopy . Some membrane proteins move randomly through -out membrane though generally at rates considerably less than would be measured in an artificially lipid bilayer. Some membrane proteins fuil to move and considered are to be immobilized

15. Structure Measuring the diffusion rates of membrane proteins by fluorescence recovery after photo bleaching

16. 3)CONTROL OF MEMBRANE PROTEIN AND MOBILITY The plasma membrane of many cells possess a febrile network membrane of cell sifting of peripheral protein situated on the cytoplasm sure face of the membrane certain proportion of a membrane integral protein molecules are enter tethered to the membrane skeleton or otherwise restricted by it.

17. STRUCTURE OF MEMBRANE PROTEIN MOBILITY

18. 4)MEMBRANE LIPID MOBILITY Computer analysis indicates that the phospholipids diffuses freely within one compartment before it jumps the “fence “ in to a neighboring compartment and than over another fence in to an adjacent compartment.

19. STRUCTURE OF MEMBRANE LIPID MOBILITY

20. 5)MEMBRANE DOMAINS IN CELL POLARITY Most membrane however exhibit district variation in protein composition and mobility ,especially in cells whose various surface display different function . The epithelial cell that line intestinal wall or make up the microscopic tubules of the kidney are highly polarized cell whose different surface carry out different function studies .

21. STRUCTURE OF MEMBRANE DOMAINS AND CELL POLARITY

22. FUNCTION OF PLASMA MEMBRANE It gives shape to the cell . It helps in transportation of molecules. Receptors are present on the startle of membrane which helps in transduction of different material. For signal transduction . It prevents the cell loss of macromolecule. It protects the cell from harmful substance .

23. CONCLUSION Plasma membrane is mainly composed of lipid and protein structure . It control the entrance and exit of molecules and ions . It is very thin elastic and permeable membrane . Plasma membrane is essential for the maintenance of cellular integrity which shows the dynamic structure of the membrane .

24. REFERANCES Gerald carp (sixth edition)cell &molecular biology . Geoffrey M.Cooper robert Hauseman –the cell a molecular approach(2009) From net-(Wikipedia ./Wiki/cell membrane) Date and time (10.30am,10/9/2013)