What makes plant cells special?
As people, our bodies are made up of different cells, each with their own role, structure and function. For example, bone cells, nerve cells, skin cells and muscle cells. The same is true of plants. Each plant is made up of different types of cells, each with its own special structure, role and function.
There are cells which absorb or let go of gases from the plant and cells which absorb or transport water. There are also cells which support the stem, trunk or stalks of a tree or plant, allowing it to stand up tall and spread its leave out to catch the sunlight. In addition, there are cells which create energy and cells which transform that energy into other things.
This last function is something that makes plant cells so different from animal cells. Because, as animals, we need to obtain our energy by eating plants or other animals, whereas plants are able to create their own energy from scratch by making use of the sun.
What do plant cells look like?
Plant cells, like human cells come in all different shapes and sizes. But one feature almost all plant cells have in common, is the wall surrounding each cell. Because every plant cell is surrounded by a rigid wall of cellulose, which is ‘glued’ to the wall of the cells next to it, giving the plant its shape and structure.
Each cell has a central nucleus and lots of smaller organelles, each of which carries out its own special task inside the cell – much like animal cells. However, another feature that plant cells have which ours do not, is the presence of a vacuole. This is a bag full of sap inside the cell, which swells up and strengthens the cellulose walls, helping to support the plant.
The vacuoles are especially important in herbaceous plants – these are the small, soft plants like daisies and sunflowers. These plants do not have strong woody trunks or branches to help hold them up. So, if the plants cannot absorb enough water to fill their vacuoles, they deflate – making the plants lose their support and wilt.
Are all plant cells green?
The reason that plants look green, is because of a pigment called chlorophyll that can be found inside organelles called chloroplasts, which live inside plant cells and absorb sunlight to make the plants’ food (photosynthesis). Chlorophyll absorbs all the colours of the rainbow, except for the colour green, which is reflects back out again, making plants look green.
However, whilst chlorophyll is extremely important for plants, not all the cells in a plant have chlorophyll inside them. Because, remember, there are many different types of cells, each with their own structure and function and while many of the cells within a plant do take part in photosynthesis, not all of them do.
For example, xylem cells are long, thick and joined at the ends like a straw, helping water absorbed by the roots to reach the top of the plant. While, phloem cells have sieve plates inside them to trap salts and sugars, stopping them from leaking away and helping to get them where they are needed.
In summary, plants are made up of many different types of cells, just like humans and other animals. But, plant cells are different from ours in a number of ways, including having vacuoles (packets of sap, which keep the plants upright and taut), chloroplasts (which contain chlorophyll to help the plants make energy) and thick, cellulose walls (which also help to support the plant and keep it from collapsing.)
In addition, like us, each cell has its own special structure and function. Some are designed to absorb water from the ground. Others suck the water that has been absorbed up, up, up to the very top of the plant. Still others help transport sugar aound the plant or store it ready for the cold months and so on and so forth.