In living organisms, the most basic functional unit is the cell. Cells make up all living things. They themselves are comprised of sub-components, called organelles. Each organelle usually has a specific task in the cell. Cells replicate via the process of mitosis to create new cells. Cells have a metabolism, creating a cellular energy from different media. Specific organelles are used in these tasks; mitochondria are used for creating energy from sugars like glucose, and chloroplasts are used for capturing solar energy, and turning it into glucose.
Plant cells are one of the major types of cells. They make up plants, such as trees, flowers, and grasses. They differ from other types of cells, such as animal cells, in that their organelles are different and they have different shapes. This site focuses on plant cells, dealing specifically with the cell parts, the cell cycle, and the Calvin cycle.