Membrane-bound structures within eukaryotic cells (cells with a nucleus) that have particular functions toward the cell's survival are called organelles. Below, I have listed some organelles and their functions.
Lysosome- Cleans toxins from the cell. This is easy to remember because lysosome sounds like the everyday household cleaner called Lysol.
Mitochondria- Cellular respiration occurs in the mitochondria. Cellular respiration is the process that converts oxygen and glucose (a sugar) into water, carbon dioxide, and a usable form of energy known as ATP (which stands for adenosine triphosphate). For this reason, the mitochondria are often referred to has the "powerhouses" of the cell.
Nucleus- The nucleus is often referred as the "control center" of a cell because it houses the genetic material called DNA (which stands for deoxyribose nucleic acid). DNA controls the functions of the cell through the indirect formation of proteins.