What are the four carbon dicarboxylic acid species?

There are 4: oxaloacetate, malate, fumarate, and succinate.

i think it is when the substance is butane

Carbon containing acids are weak acids and fatty acids for example some fatty acids are in meat

The four forms of carbon are diamond, graphite, amorphous, and white carbon (although it isn't completely proven).

The twenty amino acids are as follows: Glycine, alanine, valine, leucine, isoleucine, methionine, phenylalanine, tryptophan, proline, serine, threonine, cysteine, tyrosine, asparagine, glutamine,...