the science calorie (little c) is a measure of heat energy the food calorie (big C) is a measure of energy that we burn, but it is equal to 1,000 science calories so 1 big C is equal to 1,000 little c's.
Protists are a group made up of protozoa, unicellular algae, and slime molds. We will concentrate on the animal portion of this group: the protozoa (proto = first, zoa = animals).
Protozoa are single-celled eukaryotes (organisms whose cells have nuclei) that commonly show characteristics usually associated with animals, most notably mobility and heterotrophy. They are often grouped in the kingdom Protista together with the plant-like algae and fungus-like water molds and slime molds. In some newer schemes, however, most algae are classified in the kingdoms Plantae and Chromista, and in such cases the remaining forms may be classified as a kingdom Protozoa. The name is misleading, since they are not animals (with the possible exception of the Myxozoa).