Amoebae are single-celled organisms, consisting of protoplasma, a semi fluid, jelly-like substance, which is divided in cytoplasm and a nucleus. The latter is surrounded by the nuclear membrane, while the cytoplasm is surrounded by the cellular membrane, which serves as a mechanical and chemical boundary and provides a means of exchange of materials with the environment. This membrane is constantly immersed in water. Waste, water, oxygen, and other necessary chemicals are transferred in and out of the amoeba through the membrane.
The cytoplasm contains all of the organelles, such as the Golgi apparatus, the mitochondria and the endoplasmic reticulum. These organelles may appear as dark spots, but they are not identifiable light microscopically.