How does the palisade cell adapted to its function?
The palisade cells are the main site of photosynthesis, as they have many more chloroplasts than spongy mesophylls, and also have several adaptions to maximise photosynthetic efficiency; Large Vacuole - Restricts chloroplasts to a layer near the outside of the cell where they can be reached by light more easily.
Below the upper epidermis is the palisade layer. This is one or a few layers of cylindrical cells that contain many chloroplasts. Chloroplasts are an important part of plant cells because they are cell structures that allow for photosynthesis.
- They don't have organelles such as nuclei, mitochondria or chloroplasts. Although they do have ribosomes and a cell wall, these are both different in structure to the ribosomes and cell walls in the cells above. Bacteria cells do have a cytoplasm and cell membrane though.
- The mesophyll is the name given to two layers of cells inside of the plant's leaves. The first layer, located under the epidermis but above the second layer, is the palisade parenchyma cells. This layer is inundated with loads of chloroplasts, making it the layer most directly responsible for photosynthesis.
- Palisade cells are found in the mesophyll of a leaf and their main function is the absorption of light so that photosynthesis can take place. The palisade mesophyll consists of chloroplasts with chlorophyll that absorb the light energy.
Its main functions are photosynthesis and gas exchange. A leaf is often flat, so it absorbs the most light, and thin, so that the sunlight can get to the chloroplasts in the cells. Most leaves have stomata, which open and close. They regulate carbon dioxide, oxygen, and water vapour exchange with the atmosphere.
- These organs are broad and flat to allow for efficient light harvest. The leaves are broad to maximize surface area for light harvest and they are thin since light cannot penetrate too deeply into the leaf (the amount of light decreases exponentially with distance).
- Guard cells are cells surrounding each stoma. They help to regulate the rate of transpiration by opening and closing the stomata. To understand how they function, study the following figures.
- The epidermis protects the leaf and is transparent to let light through. Palisade mesophyll cells are tall and closely packed to absorb maximum light. They contain many chloroplasts. Most photosynthesis takes place in the palisade cells.
Updated: 2nd October 2019