All of the following can be used to define a base except (3 points) question 1 options: 1) a hydronium ion donor in a reaction 2) a substance that increases the concentration of hydroxide ions 3) an electron pair donor in a reaction 4) a substance that is a hydrogen ion acceptor in a reaction

Answer is: 1) a hydronium ion donor in a reaction.
Base is hydroxide ion (OH⁻) donor, not hydronium ion (H₃O⁺).
Lewis base can donate its lone pair of electrons to Lewis acid.
Base increases the concentration of hydroxide ions, for example sodium hydroxide or barium hydroxide in water NaOH → Na⁺ + OH⁻.

It changes food into energy that the organism can use.