Oxidation of food stuffs and redox potentials

Just an introduction to basics on oxidation of food stuffs and brief aspect of redox potentials

1. G 00d afternoon Dr. A. YOGHA PADHMA 1 ST YEAR POSTGRADUATE DEPT OF CONSERVATIVE DENTISTRY

2. OXIDATION OF FOOD STUFFS AND REDOX POTENTIALS

3. STAGES OF OXIDATION OF FOOD STUFFS

4. FIRST STAGE Digestion – Gastrointestinal tract Macromolecules Small units Example : Proteins Amino acids PRIMARY METABOLISM

5. SECOND STAGE Products of digestion Absorbed Catabolized Smaller compounds Oxidized Carbon dioxide

6. Reducing equilvalents Generated Mitochondria [Final common oxidative pathway] [Citric acid cycle] NADH and FADH2 SECONDARY / INTERMEDIARY METABOLISM

7. THIRD STAGE Reduced equivalents NADH & FADH2 Electron transport chain/ Respiratory chain [Energy is released] TERTIARY METABOLISM / INTERNAL RESPIRATION

8. REDOX POTENTILAS

9. Oxidation reduction potential Electron transfer potential Quantitative measure of the tendency of a redox pair to lose or gain electrons Oxidation – Loss of electrons Reduction – Gain in electrons Substance – Exists in reduced & oxidized state – REDOX COUPLE

10. POSITIVE & NEGATIVE REDOX POTENTIAL Substance Low affinity for electrons than hydrogen - NEGATIVE Higher affinity for electrons than hydrogen - POSITIVE Strong reducing agent – NADH [ NRP – 0.32 V] Strong oxidising agent – OXYGEN [PRP +0.82 V]

11. ATP

12. ADENOSINE TRIPHOSPHATE Adenine Ribose Triphosphate moiety High energy compound – 2 phosphoanhydride bonds – Triphosphate units ENERGY CURRENCY OF THE CELL

13. SYNTHESIS OF ATP OXIDATIVE PHOSPHORYLATION: Major source – Aerobic organisms Linked to mitochondrial ETC SUBSTRATE LEVEL PHOSPHORYLATION: Directly synthesized High energy compounds – Phosphoenol pyruvate & 1,3 bisphosphoglycerates & Succinyl CoA – Transfer high energy phosphate - ATP