Vesicles are one of the coolest organelles. They have a bubble-like shape and are made up of a membrane that is filled with fluid.
There are a lot of different types of vesicles and they have important jobs making sure the cell is healthy.
Some have compared vesicles to the trucks that we see on the highways bringing supplies and food everywhere. Each vesicle is focused on the particular cell that it lives in.
What are vesicles made of?
To do its job, vesicles need to be made of similar substances that are found in the cell, so they are made of the same cell membrane materials.
Scientists have even seen the formation of some types of vesicles when the cell membrane is pinched off.
Another important fact is that the fluid that is found inside the vesicles is typically a small amount of the cytoplasm fluid that is found outside of the cell.
This gives the vesicles the power to become fused with the cell’s membrane layers so that it can pass its cargo to the cell.
Most Important Job: Transport Vesicles
A cell’s organelles require a lot to be healthy and it’s the job of the transport vesicles to make sure that materials are moved to them.
While the vesicles have a lot of roads that they take to accomplish their duties, the one that is taken the most is from the endoplasmic reticulum, where they pack up the proteins that the ribosomes make and then they follow the highway that is made by the microtubules of the cell to the golgi apparatus.
We are familiar with trucks on our roadways being powered by gasoline, but in the vesicle world, they are pulled by special motor proteins across the microtubule highway.
Once the vesicles arrive at the golgi apparatus they blend with its membrane and they release their cargo of proteins into the golgi.
There are many occasions where proteins need to be taken to various locations within the golgi apparatus.
In those situations, transport vesicles will form from part of the golgi membrane so that they can distribute the proteins where they are needed. Once that inside job is completed, the vesicles are released back into the cell.
If the protein is going to remain inside the cell it is handed off to another transport vesicle, but if the protein is going to the cell’s exterior, it’s given to a “secretory vesicle” to finish the job.
Endocytosis
Transporting materials can be a complicated business and if the vesicles need to move materials that a cell gets from outside of the membrane it will go through a process known as “endocytosis.”
This is a pinched portion of the cell membrane that create a vesicle that holds both molecules from the cell’s exterior and the fluid. This gives the vesicle the ability to transport to other cell organelles.
A Few Types of Vesicles
While the transport vesicle is the most common type of vesicle, there are many other vesicle types that are critical for the survival of the cell.
Each vesicle type has a specific part to play in transporting materials and cell storage. No matter what kind of vesicle, they all have fluid on their interior and are surrounded by one outer membrane.
- Secretory vesicle: Responsible for moving materials from the cell’s inside to the exterior of the cell. Secretory vesicles are compared to the cell’s airplanes or ships where it takes materials from inside the country to the outside world.
- Vacuoles are larger vesicles that are found in the cells of plants. Their role is to be storage for food and water.
- Peroxisomes assist cells in energy production by using fatty acid molecules.
- Lysosomes are the stomach of the cells. These contain enzymes that are special proteins that break the food down for a cell. They work with transport vesicles to help in the digestion.
Facts about Vesicles
- Our brains contain synaptic vesicles that are a type of secretory vesicle. These are in the pre-synaptic terminals in the neurons and help in storing neurotransmitters in the brain.
- Our endocrine glands secrete hormones and some of these are stored in secretory vesicles that are then released into our bloodstreams.
- While most vesicles contain liquid, there are some vesicles that contain gases.
- The origin of the word “vesicle” is in “vesicular”, which is a Latin word that means “small bladder”.
- Vesicles can be found in both animal and plant cells.
- Since vesicles are also responsible for the transport of waste they can sometimes contain waste that could be toxic for the cell.
Interesting Facts about Biology
- Both the lymphatic system and the immune system are considered to be organ systems in the human body.
- Oils are defined as fats that remain in liquid form at room temperature. There are some oils that are good for you in small amounts, such as those from nuts and fish.
- Homozygous is when two genes are the same.
- Heterozygous is when two genes are different.
- Peptide bonds are the bonds that link protein and amino acids together.
- The scientific name for medications involved in the reduction of pain is “analgesics.”
Vesicles Quiz
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