Unlike animal cells, plant cells have a cell wall. The cell wall is made of cellulose, a rigid fiber layer. It gives the cell structure and allows for adhesion with other plant cells. Inside the cell wall is the cell membrane, a fluid structure made up of lipids and proteins. Cell membranes have channels and pumps that allow certain molecules in and out of the cell. Most pumps and channels are specific to certain molecules, like sodium and potassium.
All the components inside the plant cell, called organelles, sit in a jelly-like fluid called cytoplasm. The vacuole, a fluid-containing organelle, takes up most of the cell and allows the cell to maintain its shape.
The nucleus contains the DNA, the genetic material that encodes for all the plant’s proteins and also contains other organelles. The nuclear membrane encloses it. Inside the nucleus is an organelle called the nucleolus, where the DNA synthesizes RNA. The smooth endoplasmic reticulum (ER) is where the RNA goes to make proteins and the rough ER transports molecules throughout the cell. Next to the nucleus is the Golgi Body, whose function is to package proteins and carbohydrates that will be leaving the cell. An organelle called a centrosome sits near the nucleus and is important for cell division.
Two organelles only found in plants are amyloplast, which store starch compounds, and chloroplasts. Chloroplasts contain chlorophyll and convert sunlight into energy the plant cell can use in a process called photosynthesis.
The mitochondrion is known as the “powerhouse” in all cells. Adenosine triphosphate (ATP) is produced from glucose specifically in the christae, the little projections that are inside the mitochondrial membrane. ATP drives many important chemical reactions in cells.