All living things are made up of cells, which are the basic units of life. Cells are incredibly complex, with many parts that work together to help the cell carry out its functions. The cell membrane is a thin layer that surrounds the cell, controlling what enters and exits the cell. Inside the cell is the cytoplasm, which contains many organelles - specialized structures that perform specific functions. Some of these organelles include the mitochondria, which produce energy for the cell, and the endoplasmic reticulum, which helps the cell make proteins. At the center of the cell is the nucleus, which contains the cell’s genetic material, or DNA. The nucleus is responsible for controlling the cell’s functions and passing on genetic information to the next generation of cells.