Ion Transport Through cell Membrane

Ion Transport Through Cell Membrane

1. ION TRANSPORT THROUGH CELL MEMBRANE By- Manish Sahu M.Sc. Chemistry (Final) Sp.- Physical Chemistry

2. CONTENTS 1) Introduction 2) History 3) Definition Ion transport Permeability of lipid Permeability of protein Types Function Conclusion Reference

3. Introduction :- Cell is the structural function and biological unit of all know living organism. Cell is the smallest unit of life . All the cell are surrounded by a thin layer of membrane which is known as cell membrane .

4. History :- Definition :- Naegeli and Cramer in 1855 the structure seen under the light micros in the cell membrane. Cell membrane is the fluid layer around the cell of living thing it is some time are called plasma membrane. Membrane define the external boundaries of the cell.

5. Only small unchanged molecule can defussed freely thought phospho lipid bilayer. Some small non polar molecule such as o2,Co2 are soluble in lipid bi-layer there fore can readily small unchanged polar molecule. Ion transport Permeability of lipid Bilayer

6. Channel protein Channel protein are ion selective. They contain a pore in which solute pass at high flux when the channel is open. They transport solutes down their concentration gradien. Channel mediated transport is always passive . Permeability of protein

7. Carrier protein Carrier mediated transport maybe active or passive. Carrier proteins can be uniporters or co-transporter. Uniport :-Transportation of single solute from one side of membrane to other side . Symport :-Transportation of two different solutes from one side to another side . Antiport :- Transfer of both different solutes in opposite direction .

8. Types Active transport In this type of transport nergy is derived directly from breakdown of ARP. ATP and energy dependent The fast process Lower concentrations to higher concentrations Affected by low temperature to higher temperature Primary Active transport :-

9. Transport of Na+ and K+ by carrier protein ,Na+,K+ ATP pase is the most common example of primary active transport. Virtually every animal cell maintains lower Na+ concentration and high K+ concentration than they found in its surrounding. It is either symport are antiport

10. Secondary active transport It curs when uphill transport of one solute is coupled .with the exergonic flow of a different solutes . A common example of secondary active transport is the symport of Na+ and glucose ,whith allows Na+ and glucose to enter the cell.

11. Passive transport:- Without ATPand energy. Slower or compare to active transport High concentration to low concentration. Not affected by low temperatur. Simple diffusion :- Cell membrane are composed of phospholipid bilayer with interspersed protein. These proteins help to move larger molecule and ions across the membrane.

12. Facilitated Diffusion and ion channels:- Also called carrier mediated osmosis in the moment of molecules high concentration to low concentration. Larger molecules and ions cannot cross the membrane by simple diffusion.

13. Some membrane proteins called ion channels provide a pore for a specific type of ion to pass from one side of the cell membrane to the other . This passive transport witch requires no expenditure of energy. Is an example of facilitated diffusion. Facilitated Diffusion and transport proteins.

14. Osmosis diffusion Water moves across a semipermeable membrane from an area of high water concentration to an area of low water concentration.

15. Endocytosis Endocytosis is the ingestion of plasma membrane ingestion of food particles or large particles of foreign substances. Exocytosis Exocytosis is the method by which the objects inside the cell are taken out by the action of secretary and excretory substances.

16. Function Help in electrocytosis Transport and selective permeability Forming cell boundary Protecting cell protoplasm

17. Reference :- Biophysical chemistry- by " J.N. Gurtu and Gurtu " Biophysical chemistry- by " C.B. power and G.R. chatwar"