How A Nucleus Builds a Protein
The Complex Process of Creating Proteins
The process of creating a protein can be quite a bit confusing, so I've dedicated a short article entirely to this process. For more information about cell structure, feel free to visit my cell structure article. For more information on active transport inside of a cell, follow the link provided.
- Think of building a protein the same way you would build a house. A contractor creates a set of plans. Those plans are placed into a blueprint. The blueprint is taken to the location of the house being built. Workers bring the materials to the site, then assemble them according to the blueprints, finally creating the final product. This will all come together momentarily.
- The DNA that creates the protein (plans) is located in the nucleus (The contractor).
- A copy of DNA is made in the nucleus. This copy is called "messenger RNA" or mRNA. This is the blueprint.
- The mRNA leaves the nucleus through the nuclear pores and goes to the endoplasmic reticulum (building site).
- Ribosomes attach to the mRNA and move along the mRNA strand.
- Sets of RNA molecules called "transfer RNA" or tRNA (the workers) bring specific amino acids (building materials) to the ribosomes.
- The tRNA molecules assemble the protein (The house) according the the mRNA blueprint.
Other terms to Know
Transcription - The copying process that is done in the nucleus. Here is the process.
- An enzyme called RNA polymerase binds to the DNA at a sequence called a promoter. Think of RNA polymerase as a sprinter, who goes to the starting line of a race. The starting line is the promoter.
- RNA polymerase will travel along the DNA strand, making a copy of the DNA as it goes.
- The enzyme will then reach "the terminator," or the finish line, and will stop copying the DNA.
Translation is the process of assembling a protein, and here is how it is done:
- tRNA molecules enter the ribosome.
- Anticodons of the tRNA pair up with the codons in the mRNA.
- A peptide bond forms between the amino acids.
- The now empty tRNA leaves, and a new one enters. The process is repeated until the protein is assembled.
- Upon completion, a sequence called a stop codon will be reached. The ribosome falls apart an releases a brand new protein.