Redox reaction
A reaction where one substance loses electrons (oxidation) and another gains them (reduction). The two always happen together. Cells use carriers such as NAD+ to move electrons.
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Analogy
A relay race: the baton (electron) passes from runner to runner.
In practice
In respiration glucose is oxidised and oxygen is reduced to water.
Practice
Flashcards
- What is oxidation?The loss of electrons. Reduction is the gain of electrons.
- What is the final electron acceptor in respiration?Oxygen, which becomes water.
Questions people ask
What does OIL RIG mean?
It is a memory aid: Oxidation Is Loss, Reduction Is Gain, of electrons. If a molecule loses electrons it is oxidised, and if it gains them it is reduced. The two halves always come as a pair, because electrons lost by one substance must be gained by another.
What is NAD+ and why is it important?
NAD+ is an electron carrier made from a vitamin. When it picks up electrons and a proton, it becomes NADH. It carries electrons from glucose breakdown to the electron transport chain. Without enough NAD+, glycolysis stops, which is why fermentation exists to recycle it.