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The biochemical process by which ATP is synthesized from ADP as a result of the transfer of electrons and hydrogen ions from NADH or FADH2 to O2 through the electron carriers involved in the electron transport chain.

Pairs of biochemical reactions that occur concurrently in which energy released by one reaction is used in the other reaction

An explanation for the coupling of ATP synthesis with electron transport chain reactions that requires a proton gradient across the inner mitochondrial membrane

Functions as an uncoupling agent that allows the electron transport chain to proceed without ATP production

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3 NADH 7.5 ATP1 FADH2 1.5 ATP1 GTP 1 ATP

10 ATP

For each mole of NADH oxidized in the ETC, 2.5 moles of ATP are formed. FADH2

Produces only 1.5 moles of ATP per mole of FADH2 oxidized. FADH2‘s entrance point is beyond the first “proton-pumping” site.

In total:

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ADP + Pi ATP

ADP ATP + Pi

FOOD CATABOLISM

Oxidation of:-Carbohydrates-Fats-Proteins

LIFE PROCESSESCellular work:

-Muscle contracting-Nutrient transport-Synthesis of essential compounds

A high energy phosphate compound Its hydrolysis to ADP produces an

intermediate amount of free energy; -7.5 kcal/mole

Energy derived is biochemically useful It is larger that the amount of energy

needed by compounds used to form ATP

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Significant amounts of the remaining oxygen are converted into several highly reactive oxygen species (ROS)

ex: hydrogen peroxide, superoxide ion, hydroxyl radical

Superoxide ion that is not needed id eliminated in a two-step process governed by the enzymes superoxide dismutase and catalase, two of the most rapidly working enzymes.

1. Superoxide ion is converted to hydrogen peroxide.

2O2‾ + 2H‾ H2O2 + H2O

(superoxide dismutase)2. Hydrogen peroxide is converted to

water. 2H2O2

2H2O + O2

(catalase)

Immediate destruction of the hydrogen peroxide produced in the first of the two steps is critical, because if it persisted then unwanted production of the hydroxyl radical would occur via hydrogen’s peroxide reaction with superoxide ion.

H2O2 + O2‾ + H+ H2O + O2

+ OH

Hydroxyl radicals react quickly with other substances by taking an electron from them. Such action usually causes bond breaking.

It is estimated that 5% of the ROSs escape destruction through normal channels.

Participating in this antioxidant network are glutathione, vitamin C, and beta-carotene and vitamin E.

The vitamin antioxidants prevent oxidative damage by reacting with the harmful ROS oxidizing agents before they can react with other biologically important substances.

Biologically active compounds found in plants Compounds found in plants that have

biochemical activity in the human body even though they have no nutritional value

Antioxidant activity, cancer inhibition, cholesterol regulation, and anti inflammatory activity

Flavonoids – substances having high antioxidant activity

ROS can also be formed in the body as the result of external influences such as polluted air, cigarette smoke, and radiation exposure.

Vitamin C is particularly effective against such free-radical damage

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Vitamins Involved1.Niacin2.Riboflavin3.Thiamin4.Panthothenic Acid