Special proteins in living organisms that speed up a chemical reaction but aren't destroyed or used up are called

Enzyme.

Explanation:

The special kind of protein that speeds up the rate of chemical reaction is known as enzyme.

The enzyme does not takes part in the reaction although it enhances the rate of reaction.

The enzymes binds to the substrate and forms a complex called enzyme-substrate complex. This complex helps in product formation and the enzyme is released to take part in another reaction.

genetic variation can be caused by mutation (which can create entirely new alleles in a population), random mating, random fertilization, and recombination between homologous chromosomes during meiosis (which reshuffles alleles within an organism's offspring).