Cell Study Guide
A cell is the basic structural and functional unit of all living organisms. It is the smallest unit of life that can replicate independently, and cells are often called the "building blocks of life."
Types of Cells
- Prokaryotic Cells: These are simple cells that do not have a nucleus or membrane-bound organelles. Examples include bacteria and archaea.
- Eukaryotic Cells: These are more complex cells that have a nucleus and membrane-bound organelles. Examples include plants, animals, fungi, and protists.
Cell Structure
Cells have several key structures, including:
- Cell Membrane: The outer boundary of the cell that separates the internal environment from the external environment.
- Nucleus: The control center of the cell that contains the genetic material (DNA).
- Cytoplasm: The gel-like substance inside the cell where organelles are suspended.
- Organelles: Specialized structures within the cell that perform specific functions, such as the mitochondria for energy production and the endoplasmic reticulum for protein synthesis.
Cell Functions
Cells perform various functions, including:
- Metabolism: Cells carry out chemical reactions to obtain and utilize energy.
- Growth and Reproduction: Cells grow and divide to create new cells through processes like mitosis and meiosis.
- Homeostasis: Cells maintain a stable internal environment despite external changes.
- Communication: Cells communicate with each other through chemical signals and receptors.
Cell Theory
The cell theory states that:
- All living organisms are composed of one or more cells.
- The cell is the basic unit of structure and organization in organisms.
- All cells come from pre-existing cells through the process of cell division.
