The nucleus of the cell acts like the control center, storing the information needed for the cell to do everything it needs to do. This lesson will discuss how that information is stored and used.
What is a Cell?
Before we talk about what the nucleus does for a cell, we need to first define what a cell is.
Here’s the technical definition: a cell is the smallest unit of life. This means a cell can do all the things a human can do, such use energy, grow and reproduce, and respond to things happening around it. Obviously, this happens at a much smaller level. The parts of a cell that perform certain functions are called organelles, or little organs that have specific jobs, just like the organs in your body.
One of these organelles is the nucleus.
What is the Nucleus?
The nucleus of the cell is often called the control center or the brain of the cell. It is separated from the rest of the cell by a structure called the nuclear envelope. The nucleus contains the cell’s DNA. DNA is like the instructions that tell a cell how to be a cell.
The DNA in the nucleus is wrapped around proteins, forming a structure called chromatin. One long strand of chromatin is called a chromosome. To better picture this, think of a wool scarf.
The chromatin is like the material, or the yarn, that makes up the scarf. Put enough material together in a highly organized pattern, and you have a full scarf, which is like the chromosome.Why does the DNA need to be packaged up like this? Besides providing more vocabulary words for biology students to learn, this packaging helps ensure that the DNA can actually fit into the cell. Going back to our scarf and yarn analogy, a skein of yarn that is wrapped up nicely doesn’t take up much space.
However, if you give said yarn to a two-year-old child, that yarn will end up covering the whole floor. Being nicely wrapped up makes the DNA, like the yarn, much more compact.
What Is DNA?
The DNA in the nucleus contains the instructions for the cell to make proteins. Proteins are essentially the tools of the cell. They can make reactions happen, help move things in and out of the cell, and form muscles, hair, and nails.
They also carry nutrients through your body. Proteins are molecules that make things happen.How does DNA make protein? DNA is a code that tells the cell how to make proteins. The code is taken outside the nucleus via DNA’s cousin, RNA.
The RNA is like a middle man that takes the directions from the nucleus to another organelle, called the ribosome, that then makes the protein. The DNA is like the boss, sending instructions out the workers via its messenger, the RNA.
What Is the Nucleolus?
Besides DNA, the nucleus is home to another organelle called the nucleolus, or little nucleus.
Under a microscope, the nucleolus appears as a dark area inside the nucleus. The nucleolus is actually made from DNA, but this DNA has a specific purpose. The DNA in the nucleolus provides the code to make ribosomal RNA. As the name implies, ribosomal RNA is RNA that makes up the ribosomes. So, not only does the nucleus have the instructions for how to make proteins, but also the instructions to make the things that make the proteins.
The nucleus is an important organelle that houses the instructions for a cell, telling the cell how to make its proteins. The instructions are found in the form of chromatin, a material made of DNA packaged around proteins.
The instructions from DNA are sent in the form of RNA to the ribosomes, which will then make the protein. The nucleolus is also housed in the nucleus. It provides the instructions for making ribosomes.