Protein Synthesis
, Protein Synthesis
Proteins
Proteins are small molecules within cells, and they're needed for all structure and function
inside cells. Proteins play a crucial role in the body by serving various essential functions that
are vital for overall health and well-being. These complex molecules are involved in building
and repairing tissues, as well as supporting the structure of muscles, skin, and organs.
Additionally, proteins are key players in important bodily processes such as enzyme
reactions, immune system function, and hormone regulation. Their diverse functions underline
the significance of consuming an adequate number of protein-rich foods to ensure optimal
physiological functioning and support overall health. Proteins wear out over time, so our cells
are constantly creating new proteins through the process of protein synthesis.
Protein synthesis has two key steps, transcription (making mRNA) and translation (making the
protein).
Types of RNA
Different types of RNA assist with the role of protein synthesis.
They are:
messenger RNA (mRNA) - carries a message from the DNA out of the nucleus
transfer RNA (tRNA) - carries amino acids to the mRNA
ribosomal RNA (rRNA) - part of matching the tRNA and the mRNA
Step by Step of Protein Synthesis:
1. Transcription
In transcription DNA makes and codes mRNA
When DNA unwinds transcription begins
RNA polymerase (an enzyme) catalyses' the process and separates the strands of DNA.
Polymerase attaches to a strand and moves along it, allowing new nucleotides to pair up
with complementary nucleotides. DNA strand contains the code and therefore is referred
to as a template.
A sugar-phosphate backbone is attached to the nucleotides, and a new strand of mRNA is
produced.
the nucleotide sequence of the template DNA nucleotides determines the nucleotide
sequence of mRNA. E.g. if in DNA it is ATCCG then in mRNA it will be UAGGC
Think of the process of Transcription as DNA transcribing its genetic code to the mRNA.
In mRNA Adenine bonds with Uracil and not Thymine.
A strand of mRNA breaks away and the DNA rewinds.
With this new Transcribed Genetic code the mRNA is able to leave the nucleus via the
pores of the membrane and takes the genetic code to the ribosomes where protein
synthesis can take place.
In short: The process of transcription copies DNA to mRNA. After the copying, the mRNA is
sent to a compartment of the cell called a ribosome, which does the next step, translation.