Mung beans and soybeans are different beans. Green beans are leguminous plants and belong to the genus Vicia. Pods and beans are green when they are ripe. On the other hand, soybean is another leguminous plant belonging to the genus Soybean, and its pods and beans are yellow when they mature. The nutritional value of mung bean and soybean is similar. They come from different plants. Mung beans will not become soybeans when they mature.