Thursday, October 30, 2008

Key Differences between Plant and Animal Cells

Plant and animal cells share many similarities, as well as some differences. Each cell is distinct in its structure, and therefore, distinct in its function.

To start off, both plant and animal cells are eukaryotic (have a nucleus). There is a cytoplasm in both which holds the organelles, and a cell membrane which engulfs the gel-like cytoplasm. The cell membrane protects the cell, regulating what can and cannot enter into the cell. Both cells have mitochondrion, which is the energy producer of the cell (you may think of it as the cell’s power plant). Also, both cells contain vacuoles, which are organelles dealing with cell digestion and storing wastes to be exported.

Image courtesy of National Taiwan Science Education Center

The first key difference is that the vacuole in plant cells is much larger than that in animal cells. In addition to the digestive function of vacuoles, plant cells use their vacuoles to store water. When plants are stiff and upright when well-watered, then their vacuoles are filled. Another difference is that plant cells have chloroplasts while animal cells do not. Chloroplasts, rich in chlorophyll, absorb light and conduct photosynthesis, providing the cell with the energy it needs. The energy from photosynthesis then goes to the mitochondrion which manages this energy for various functions (i.e cell division, mobility and nourishment). The third difference is the presence of a cell wall in plant cells, which give the plant the strong skeleton it needs to grow and survive. Cell walls are made of cellulose, a complex sugar. Cell wall strength may vary- large trees have stronger cell walls than a small fern, which is easily moved by wind.

To recap, plant cells have a larger vacuole, chloroplasts, and a cell wall, unlike animal cells. Keep in mind how structure leads to function. Which organelle is responsible for the droopiness of a plant? And why do plants regain their exact same structure when watered? As for animal cells, why do you think they have small vacuoles?

Text adapted from Wisegeek

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