Animal cells, compared with plant and fungi cells, do not need a cell wall. In its place, multicellular animals have other constructions that give support to their tissues and organs, including skeleton and cartilage. Within a bridge action, the pyruvic acid enters the mitochondrial matrix and binds to Coenzyme A https://www.generationgenius.com/videolessons/plant-and-animal-cells-video-for-kids/