It may seem somewhat obvious to say that plants and animals are different. Any six year old can tell the difference between a tree and a dog. But those differences are far deeper than just what the organisms look like. The very cells that plants are made up of have very specific structures. In particular, the cell wall of plants have some unique characteristics. So what are the characteristics of plant cell walls.
First of all, it’s important to note that not all plant cells have a cell wall as is about to be described. In addition, there are many variations depending on the species of plant. The descriptions here are meant to be what an “average” plant cell wall is like.
The cell wall of a plant is located on the outside of the cell membrane. It is usually rigid, but the degree of flexibility of the cell wall varies depending on the particular function the cell has in keeping the plant alive. Cells that make up the trunk of a tree are obviously going to be less flexible than cells on a leaf.
Cell walls act in a variety of ways. They serve to protect the structure of the plant. They provide structure and support, as well as aiding in the movement of chemicals and wastes in to and out of the cell. One of the more important roles of a plant cell wall is to regulate the amount of water that goes in and out of the cell. Plants must have good water regulation systems, allowing them to retain water during dry periods, and get rid of excess water if they must. Plants can’t walk around to find water, making this process very important.
Plant cell walls are made with a variety of carbohydrates. There are three primary carbohydrates that are used in most plant cell walls. These include pectin, cellulose, and hemicellulose. Of course, there are many other components – but these are the major players. The cellulose and hemicellulose form a complex matrix, which is then embedded in the pectin. The exact structure is quite complicated.
Some of the other components of a plant cell wall are equally important. There are various enzymes that serve a wide variety of metabolic functions. Without these enzymes, the cell wouldn’t be able to move chemicals in and out of the cell properly, and the cell would soon die.
Certain plants have a secondary cell wall. If it is present, this structure is usually involved in providing extra physical support.
So there you have it – the basic characteristics of a plant cell wall. Of course, there are many details that cannot be included here due to space constraints. A complete study of plant cell walls requires a good size text book and a few courses in plant biology.