hydrophobic interaction

Introduction

History
Definition
Types of interaction.
Hydrophobic interaction
Vander Waals interaction
London dispersion forces
Hydrogen bonds
Charge .charge interaction

Example of hydrophobic interaction
Sodium oleate micelle
protein stability
Ligand binding specificity

Conclusion.
References.

1. HYDROPHOBIC INTERACTION ) By KAUSHAL KUMAR SAHU Assistant Professor (Ad Hoc) Department of Biotechnology Govt. Digvijay Autonomous P. G. College Raj-Nandgaon ( C. G. )

2. SYNOPSSIS Introduction History Definition Types of interaction. Hydrophobic interaction Vander Waals interaction London dispersion forces Hydrogen bonds Charge .charge interaction Example of hydrophobic interaction Sodium oleate micelle protein stability Ligand binding specificity Conclusion. References .

3. INTRODUCTION Water is needed not only for biochemical reactions but also for transporting substances across membranes maintaining body temperature dissolving waste products for excretion and producing digestive fluids. Many of the weak interactions within and between biomolecules are strongly influenced by the solvent properties of water .

4. HISTORY Faraday symp 1982 . T.S.More and T.F. win mill with first mention of the hydrogen bond in 1912. As reported by the ancient Greek philosopher Thales of Miletus around 600 BC.

5. DEFINATION The tendency of nonpolar molecules in a polar solvent (usally water ) to interact with one another is called the hydrophobic effect. The interaction between the nonpolar molecules are called hydrophobic interaction- The hydrophobicity of amino acid residues is defined by a system know as hyrophobicity scales.

6. TYPES OF INTERACTION HYDROPHOBIC INTERACTION. Hydrophobic interaction describe the relation between water and hydrophobic . Hydrophobic are nonpolar molecules and usually have along chain of carbons that do not with water molecules the mixing of fat and water is a forces that are acting upon both water and fat molecules are too weak however this is not the case the behavior of fat droplet in water has more to do with the enthalpy and entropy of the reaction than its intermoleculas forces .

7. HYDROPHOBIC INTERACTION

8. EXAMPLE OF HYDROPHOBIC INTERACTION Interaction between water and nonpolar compound- When water is mixed with a hydrocarbon such as hexane two phases from other liquid is soluble in other.

9. Amphipathic compound Contain regions that are polar and regions that are nonpolar when amphipathic compounds are mixed with water the two regions of the solute molecule experience conflicting tendencies.

10. Sodium oleate micelle An example of and amphipathic bimolecule that ends to from micelles is the sodium salt of the long chain fatty acid oleic acid . This molecule has a single carboxyl group which is polar and thus tends to hydrate readily and a long hydrocarbon tail Which is nonpolar and intersically insoluble in water because of this long hydrophobic tail there is very little tendency for sodium oleate to dissolve in water to yeild a true ionic solution however.

11. Sodium oleate micelle

12. Protein stability Protein stability is just the differences in free energy between the correctly folded structure of a protein and the unfolded denatured from. The more stable the protein the larger the free energy differences between the unfolded from and the native structure.

13. protein stability -

14. Ligand binding specificity Both the protein and the ligand are solvated by water when they are separated as the two surfaces interact water is excuded hydrogen bond are broken and formed hydrophobic interaction occur and protein and ligand stick to each other.

15. VANDER WALLS INTERACTION Vander Waals forces include attraction and repulsions . Atom molecules and surfaces as well as other interaction forces . They difficult from covalent and ionic bonding in that they are caused by correlations in the fluctuating pal creations of near by particle .

16. LONDON DISPERSON FORCES Named offer the German, American physicist . Fritz laden are weak intermolecular forces that arise from the interactive forces between instantaneous multiples in molecules without permanent multiple moments . London dispersion forces are also know as disposition forces ,London forces or instantaneous dipolar induced dipole forces .

17. HYDROGEN BONDS A hydrogen bond is the attraction interaction between polar molecules in which hydrogen is bound to highly electronegative atom such nitrogen ,oxygen, fluorine. The hydrogen bond is something of a misnomer as it not a true bond but a particularly strong dipole-dipole in attraction and should not be confused with a covalent bond.

18. STRUCTURE OF HYDROGEN BOND

19. CHARGE- CHARGE INTERACTION Electric charge the physical property of matter that causes if to experience a force when close electrically charged matter. There are two types of electric charges called positive and negative. The electric charge is a conserved property of some subatomic particles which determines their electromagnetic interaction.

20. STRACTURE OF CHARGE INTERACTION

21. CONCLUSION Hydrophobic interaction are similarly weak and ionic interaction and hydrogen bonds are only a little stronger. A typical hydrogen bond can be broken by the input of about 20kj/mol . In aqueous solvent at 250C . The available thermal energy is of the same order as the strength of these weak interaction . Consequently hydrogen bonds and ionic hydrogen and Vander Waals interaction are continuously formed and broken.

22. REFREANCE J.L. JAIN (sixth revised and enlarged edition) NELSON &Cox-(principles of biochemistry 5th edition) ALBERT L. LEHNINGER-(biochemistry 2nd edition) FROM NET-(Wikipedia ./Wiki/hydrophobic –effect .) Date and time (10.30am,14/8/2013)