Protein Synthesis
The process of Protein synthesis has two stages transcription and translation.
Transcription is the first stage and it is composed of 3 steps. It all starts in
the nucleus of a cell with a strand of DNA. The strand of DNA is unzipping and unwinding which is when the DNA becomes flat and DNA helicase goes up the strand and breaks the hydrogen bond between nucleotides and they become two different single strands of DNA. The second step in transcription is complementary base pairing. That starts with a single strand of mRNA finds a single strand of DNA and lines up with and starts complementary base pairing which is creating a hydrogen bond with each other. Except its different than DNA replication because the mRNA is copying the message of nucleotides on the DNA strand. Once the mRNA copies the DNA message the third step is separating from the DNA but before the mRNA leaves mRNA polymerase comes and translates the mRNA and turns all the thymine to uracil. Then the mRNA goes and leaves the nucleus to find a ribosome and starts the second stage of protein synthesis translation.
Once the mRNA leaves and is in the cytoplasm of the cell, and a ribosome laches on the the mRNA which is the first step of translation called initiation. Now that the ribosome is attached the second step starts called elongation. In elongation, the ribosomes is attached and it allows complementary base pairing between the mRNA and the tRNA which has a amino acid on it. The tRNA has an anti codon which will fit to a certain codon on the mRNA. So the ribosome reads the codon and finds the right anti codon which brings the tRNA with the anti codon to the P spot on the ribosome and attaches to the mRNA. Once attached, the amino acids on the top of the tRNA attaches to the amino acid beside it. Then the tRNA in the A spot has no amino acid attached, so it lets go and the ribosome moves down the mRNA so the tRNA is in the A spot and a new anti Condon attaches to the P spot and the amino acids keep attaching to
each other as the ribosome goes down the mRNA. At a certain codon the ribosome will read STOP and then the last step is termination. In termination the ribosome reads STOP so no tRNA will fit on the mRNA and the chain of amino acids will stop and the ribosome will let go and and the polypeptide chain leaves and is now a primary structure of protein.
source: class one note