Different structures are positioned in our bodies at different places to help us carry out life-sustaining processes without any hiccups. Similarly, different structures are present at a cellular level to perform varied tasks. The general perception of cells is that of a well-organized collection of different materials and organelles. We thought that we almost knew everything there was to know about these small units of life. A new study has sprung a new surprise as researchers have discovered a surprising structure inside an organelle. The mind-blowing thing is that this organelle has been in plain sight for decades.
A discovery has been made inside a cell organelle named peroxisome. It is a simple part of a cell and has a single membrane filled with a granular protein matrix called a lumen. The primary role of these organelles lies in breaking down and synthesizing molecules for the cell. The new study has surprisingly found vesicles inside peroxisomes, something we had no idea existed within it. These organelles are found in the cells of all multi-cellular organisms, where they float around and remove reactive molecules containing oxygen and help in breaking down fats. In animals, they are only 0.1 micrometers in length, which makes them hard to discern from a microscope.
This is because the peroxisomes’ size is less than the resolution of light, which means that they only show up as a dot in fluorescence microscopy. To work around this problem, the scientists started studying the peroxisomes of watercress or Arabidopsis thaliana, which has large peroxisomes (9-12 micrometers). This is big enough to see what is going on inside these organelles. The study revealed that in addition to the external membrane in peroxisomes that we know about, there are many such membranes inside.
These membranes are known as vesicles, which are floating through the lumen in the organelle. Vesicles’ primary function is to transport molecules inside a cell or an organelle by keeping them in a watertight cocoon, which keeps them away from any kind of unwanted reaction. This new study has single-handedly changed the widely held misconception about peroxisomes being simple, single-membrane organelles. While the peroxisome is not as important as the nucleus or the mitochondria, this discovery is very exciting as it may lead to the unraveling of many more mysteries.
It is still unclear whether the peroxisomes found in animal cells are similar in structure and whether this is the same process they use to carry out their functions. More research into that is required, and hopefully, this mystery will be solved soon as well.