Discuss at least 3 key differences in the structures of plant and animal cells. Be sure to explain why plant and animal cells have (or do not have) these key structures based on the functions the cells must carry out.
One key difference in the structure of plant and animal cells is the presence of a cell wall in plant cells but not in animal cells. The cell wall is a rigid layer outside the cell membrane that provides support and protection to the cell. Plant cells require this structure because they need to maintain a certain shape and withstand the pressure created by the internal fluids and the environment. Animal cells, on the other hand, do not have a cell wall because they do not need the rigid support. They have a flexible cell membrane that allows them to change shape and move.
Another difference is the presence of chloroplasts in plant cells but not in animal cells. Chloroplasts are specialized organelles that contain chlorophyll, which is responsible for photosynthesis – the process by which plants convert sunlight into energy. Plant cells need chloroplasts to produce their own food, while animal cells obtain their energy by consuming other organisms or organic matter. Therefore, animal cells do not need chloroplasts and do not have them.
A third difference is the presence of a large central vacuole in plant cells but not in animal cells. The central vacuole is a membrane-bound sac that occupies a large portion of the plant cell's volume. It is filled with water, nutrients, and waste products and helps maintain the turgidity of the cell, provide structural support to the plant, and store nutrients. Animal cells, on the other hand, usually have several smaller vacuoles that are involved in storing and transporting materials. They do not have a large central vacuole like plant cells because they do not require the same level of water storage and structural support.
Overall, the structures present in plant and animal cells are based on the specific functions these cells need to carry out. Plant cells have structures like cell walls, chloroplasts, and large vacuoles to support photosynthesis, maintain shape, and store nutrients. Animal cells do not have these structures because they obtain energy through different means, have a more flexible structure, and have different requirements for storing materials.