Only plant-like cells have a cell wall and its main purpose is to act as a protective barrier for the cell.
Since the cell wall is designed to give the cell structure and stability, they are mostly made up of cellulose fibers as well as pectin, and hemicellulose.
The more layers, the thicker the cell wall and they can also bond together for additional strength. Cellulose, pectin and hemicellulose are types of of sugar, however, it is one that doesn’t dissolve in water as so many other types of sugar.
The nature of plants and their growth style require that they have cell walls. They are outside, getting energy from the sunlight and need to grow tall.
This situation means that they have to be strong enough to hold their own weight as they grow. Although flexible, they must be able to continue to grow without collapsing.
If animals had these kinds of cell walls, we would all be too stiff to be able to move or walk around. For animals, we have bones that give us structure and durability and the way they are constructed lets us move freely.
Looking Deeper into cell walls
At first glance, you might think that a cell wall is structurally solid, but this isn’t the case. Cell walls are covered in small holes and they actually appear more like a chain-link fence.
The holes in the cell wall are called “plasmodesmata,” and these are the entryways for waste to leave and food to enter.
Astoundingly, the plasmodesmata are also small roadways for the connection of cells to come together in resource sharing.
The job of the cell wall
The protection of the plant cell is the highest priority, and cell walls accomplish this by being structurally sound due to the content of cellulose fibers that are found inside the walls.
If you look inside the walls you will see all of the plant cell organelles and each organelle has its own duty to perform.
The cell wall maintains the health of the cell by letting only approved nutrients in and waste exit; and it does this with the help of the cell membrane that is located next to the cell wall.
The cell membrane is the manager and makes the choices for what can enter and leave.
Cell walls protect even when there is loss of water
Since the cell wall has holes, one of the problems can be that during the heat of the day the cells in the plant can lose water.
This loss is called “transpiration” and can happen when the air heats up and there is a decrease in water vapor pressure.
The water is released through “stomata” which are the pores on the plant’s surface. However, thanks to the plant’s cell walls, they keep the basic shape of the cell intact.
The plant might look like it’s wilting, but the cell walls let it come back to normal when water is added.
Fun Cell Wall Facts
- Cell walls: filter and traffic cop – Cell walls act as a kind of “filter”, but they also have another job acting as a pressure vessel. When too much water tries to enter a cell (a process called osmosis), the cell wall will stop the over-expansion process and keep the extra water out.
- Criss-Cross for strength – When cell walls are being created they are laid down in different directions so that they are stronger.
- Add glue to the cell wall mix – Plant cell walls have to be tough and flexible. One of the ways that they reinforce their stability is by having an added substance or “glue” that holds the fibers together even better.
- Cell walls coordinate with vacuoles – The vacuole in a cell is a kind of waste storage area. The plant cell walls work closely with vacuoles to make sure that waste exists in the best manner.
- No bones for plant cells – If a plant had bones instead of the cell walls, it would topple over and die before it reached maturity.
Interesting Facts about Biology
- The human femur bone is considered to be the strongest bone in the body and is stronger than concrete.
- When we shiver, our bodies are releasing a hormone called “irisin,” which is also called the exercise hormone that converts your body fat to heat.
- Scientists continue to learn the importance of gut bacteria in overall good health. There are over 100 trillion bacteria in the average human gut.
- Do you know what type of blood that you have? Blood is categorized in 4 types: A, B, AB, and O.
- Here’s a creepy piece of information: when it comes to cells, the average human body has more that is non-human, than human.
- The human brain works less during the day when we are awake than when we are asleep.
Cell Wall Quiz
Now let's test what you have learned!
