Question

Oxidation reduction reactions ________. oxidation reduction reactions ________. may involve the loss of hydrogen and electrons are rarely coupled together utilize hydrogenases occur via the gain of hydrogen or the loss of oxygen

Answer 1

Oxidation-Reduction (REDOX) reactions can be defined with respect to electrons and Hydrogen and Oxygen.

Electrons:
                In a reaction the atom which looses electron(s) is said to be oxidized (reducing agent) and the atom which gains electron(s) is said to be reduced (oxidizing agent).

Oxygen-Hydrogen:
                            In a reaction if a reactant looses hydrogen or gain oxygen is said to be oxidized and the reactant which looses oxygen and gains hydrogen is said to be reduced.

Result:
           The correct answer is "May involve in loss of Hydrogen and Electrons".