The chemical bonds
- 1. Biochemistry for nurses The Chemical Bonds
- 2. Dr Hakim Mehenni Email: [email protected] https://sites.google.com/site/drhakimmehenni/ Biochemistry for nurses
- 3. The Chemical Bonds • The chemical bond is a link between 2 atoms to give a molecule. • The chemical bond is composed by 2 electrons coming from the outer layer of each different atom to make a pair of electron. • 4 types of chemical bonds: Nonpolar covalent bond, Polar covalent bond, Ionic bond and Hydrogen bond. nucleus Outler electron ATOM (hydrogen, oxygen, carbon…) Biochemistry for nurses
- 4. Nonpolar covalent bond • Same forces of attraction onto the electron pair • The electron pair is situated at same distance between the 2 atoms. • Often between same atoms (H2, O2, C4…) Attractive forces (A = B) Biochemistry for nurses
- 5. Polar covalent bond • Different forces of attraction onto the electron pair • The electron pair is situated closer to the more electronegative atom than other. • Often between 2 different atoms (H2O, NH3, CH4…) • Attractive force of B > attractive force of A • Electronegativity of B > electronegativity of A • Donor atom (δ+) = A • Acceptor atom (δ-) = B Biochemistry for nurses
- 6. Polar Molecules Biochemistry for nurses
- 7. Ionic bond • An atom can win or lose electrons: Oxidation = the atom loses electrons (ex: Na+ ); Reduction = the atom wins electrons (ex: Cl- ). • The Oxidation and Reduction produce Ions. An ion is atom having a missing electron (+) or an extra electron (-). An ion is electrically charged + or – • An ionic bond is an interaction (attraction) between 2 ions having opposite signs. Ionic compounds are salts! Biochemistry for nurses
- 8. Hydrogen bond • A hydrogen bond is a attraction between polar molecules that occurs when a hydrogen (H) atom is bound to a highly electronegative atom (acceptor atom(δ-)). That hydrogen (donor δ+) is attracted towards some other nearby highly electronegative atom such as Oxygen (O), Nitrogen (N), Fluorine (F). Biochemistry for nurses
- 9. • These Hydrogen bonds can occur between different molecules (intermolecular) such as water, or within different parts of the same molecule (intramolecular) such as DNA. • The hydrogen bond is weaker than covalent and ionic WATER DNA Biochemistry for nurses
- 10. • These Hydrogen bonds can occur between different molecules (intermolecular) such as water, or within different parts of the same molecule (intramolecular) such as DNA. • The hydrogen bond is weaker than covalent and ionic WATER DNA Biochemistry for nurses