Is Cell Wall Permeable: 9 Interesting Facts You Should Know

Permeability is the rate in which any substance can pass through a certain passage or any barrier. Let us have a deep view on the permeability of the cell wall.

The cell wall is completely permeable. In many organisms, cell wall is the source of nutrient exchange and other molecules including hydrogen oxide. Therefore, it has to be permeable in order to accept the nutrients for their personal benefit and also for the survival of the specific cell/organisms.

Let us discuss the reason why cell wall is permeable, when are they fully permeable, why and when are they semi-permeable, along with the elements that can pass through a cell wall and many other related facts in this article.

Why is the cell wall permeable?

Cell wall functions by protecting the cell against any damages. Let us discuss why the cell wall is permeable.

The cell wall is permeable because the primary mode of nutrient uptake takes place with the aid of cell wall’s permeability. Only when the cell wall allows or approves the solvent and the solute inside the cell, the nutrient absorption takes place. Thus the cell can sustain without any impairment.

When are cell walls fully permeable?

Fully permeable means letting in all the elements (solutes etc) inside the cell wall. Let us see if there is any specific factor involved in this permeability in the cell wall.

Cell walls are fully permeable when it allows tiny molecules inside the cells in the size of 30 to 60 kilo dalton. These tiny molecules can be hydrogen oxide or any nutrient. This is specially for plants as 90% of their nutrient uptake is from water.

Though the cell wall, specifically in plants, is completely or fully permeable all time, the other layers like cell membrane or the plasma membrane have few rules and regulations to the elements that can enter and not enter.

Is cell wall selectively permeable or semi-permeable?

Selectively permeable or semipermeable is a factor in which only specific or particular elements are allowed. Let us see about the cell wall permeability.

The cell wall is fully permeable but the cell membrane inside the cell is selectively permeable or semi permeable as the cell membrane is the layer that selects and rejects the elements that it needs and rejects unwanted elements for tonicity and nutrient uptake.

When are cell walls semi-permeable?

Though the cell wall lets in all the substances, how does it actually work? Let us have a deeper look on it.

The cell wall is fully permeable for all substances at any time. These substances get collected inside the periplasmic space or periplasmic vacuoles and wait for the signals from the cell membrane to enter. After analysis, the cell membrane, which is semi permeable, lets in the selected elements alone.

Why are cell walls semi-permeable?

Cell wall regulates the cell growth direction and provides morphological support while maintaining the cell shape. Let us see if and why they exhibit semi-permeable nature.

Cell walls are not semi permeable, they are fully permeable as their bound purpose is to let in all the substance inside the cell and store them in periplasmic space.

Is plant cell wall permeable or semipermeable

The plant cell wall is rigid and aids in protection for the cell against various factors. Now let us have an explicit view on their permeability.

Plant cell walls are permeable as it let in substances like hydrogen oxide, minerals (nitrogen, phosphorus,  potassium etc), ions (magnesium, nitrate) and other nutritive compounds. For survival, plants has to utilize these elements to thrive and sustain on Earth.

800px Drawing of Cell Wall
Image Credits: Cell wall by Captain MarcusL (CC BY-SA 4.0)

What can pass through a cell wall?

The cell wall helps in the transportation of essential molecules and in the storage of carbohydrates. Let us see what all things can pass through a cell wall.

Cell wall allow substances less than 10000 dalton in size. The substances that can pass through the cell wall are hydrogen oxide molecules, gasses, hydrophobic molecules like lipids etc.

Does the cell wall allow water to pass through?

Water is an essential element in every living organism. We will now have a look if the cell wall permits water inside the cell.

The cell wall allows water inside the cell as the chemical name of water is hydrogen oxide and it is less than 10000 dalton in size. The best example is watering plants. Addition of water to plants is very important as the water from the soil is absorbed by the plant cell wall for nutrient uptake.

Is the cell wall permeable to sugar?

Sugars or carbohydrates are the biomolecules that are essential elements in all living organisms. Let us have a look if they can pass through the cell wall.

Cell wall is not permeable to sugars, especially sucrose. Sugars are large molecules and also play a significant role in all biochemical processes inside the cell, but they are not allowed through the cell wall due to their size. Hence, cell collects raw materials and then synthesizes their own sugars for survival.


The article is about the permeability of the cell wall and about the elements that can pass through and are rejected by the cell wall. It also focuses on the major factor involved in the cell permeability, that is size of molecules.

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