The human body is composed of trillions of cells, which are the basic structural, functional, and biological units of all living organisms. Each human cell has several key components, including:


1. **Cell Membrane**: A lipid bilayer that surrounds the cell, providing structure and regulating the movement of substances in and out of the cell.


2. **Cytoplasm**: The gel-like substance within the cell membrane that contains all the cell’s organelles, excluding the nucleus.


3. **Nucleus**: The control center of the cell, containing genetic material (DNA) and responsible for regulating cell growth, metabolism, and reproduction.


4. **Mitochondria**: Known as the powerhouses of the cell, they generate ATP through cellular respiration, providing energy for cellular activities.


5. **Ribosomes**: The sites of protein synthesis, where genetic instructions from the nucleus are translated to build proteins.


6. **Endoplasmic Reticulum (ER)**: A network of membranes involved in protein and lipid synthesis. The rough ER has ribosomes on its surface, while the smooth ER does not.


7. **Golgi Apparatus**: A series of stacked membranes that modify, sort, and package proteins and lipids for storage or transport out of the cell.


8. **Lysosomes**: Contain digestive enzymes that break down waste materials and cellular debris.


9. **Cytoskeleton**: A network of protein filaments and tubules that provides structure, shape, and movement to the cell.


10. **Centrosomes and Centrioles**: Involved in organizing microtubules and in the process of cell division.

These components work together to maintain the cell’s health, replicate genetic material, produce energy, synthesize proteins, and carry out a wide range of essential biological functions.