Biology: Cell Structure
The Plant Cell
The cellular organelles described in this topic occur in both animal and plant cells. However, plant cells have three additional structures not found in animal cells. These are:
- A cell wall, which is composed of proteins and carbohydrates, including cellulose.
- Chloroplasts are the organelles where photosynthetic eukaryotes use light energy to make carbohydrates from carbon dioxide and water. Chlorophyll, the green pigment essential for photosynthesis to occur, and associated accessory pigments (such as carotenes) occur in the chloroplast. Chloroplasts also contain a small amount of DNA.
- A central vacuole, which stores water, ions, nutrients, and wastes. When the vacuole is full, the cell becomes rigid, which enables plants to stand upright.
All cells have a cell membrane surrounding their cytoplasm. Plant cells have a cell wall outside of the cell membrane, in which a variety of chemicals are incorporated. The structural polysaccharide cellulose is the most common chemical in the plant cell wall. This wall provides strength and support to the cells. Bacteria, plants, fungi, and some protists (such as algae) have cell walls.
However, not all living things have a cell wall, most notably members of the animal kingdom and many of the more animal-like protists, such as Amoeba and Paramecium. Cells in those groups have only a cell membrane to uphold the structural integrity of the cell.
 Try this practice activity to test your knowledge of the Eukaryotic Plant Cell parts.
Try this drag and drop for a review of the terms in section 1.
 Now that you have reviewed all of the course material in this section, go back and retake C-Quiz 1. Once you have successfully mastered (passed) C-Quiz 1 proceed to C-Quiz 2, which is worth 10 points. |
