What is the predominant fuel used by muscle cells during low- or moderate-intensity activity?

Fat is the predominant fuel used by muscle cells during low- or moderate-intensity activity. Both fat and carbohydrates are used to fuel exercise by muscle cells. At lower or moderate intensities activity more fat is used while at high intensities activity, more carbohydrates are used.

unicellular organisms, like bacteria, are able to perform all life functions within one single cell. multicellular organisms need many different types of cells to carry out the same life processes. each of these special types of cells has a different structure that it perform a specific function.