Protein Synthesis Flashcards
What are the two processes of Protein synthesis called?
- Transcription
- Translation
What genes?
code for proteins
How are genes expressed?
are expressed when they are transcribed into mRNA and then translated into a protein.
What is transcription ?
The production of mRNA by using DNA as a template. A length of DNA (a gene) is transcribed into a mRNA molecule. This occurs in the nucleus.
What is translation?
Translating the base sequence of the mRNA molecule into an amino acid sequence. This occurs at a ribosome.
Stop codon
mark the end of the polypeptide chain
What is the first step of transcription ?
RNA polymerase unwinds a section of DNA (gene) that is required for protein synthesis.
what is the second step of transcription ?
RNA polymerase breaks the hydrogen bonds between bases in the middle of the double helix.
What is the third step of transcription ?
RNA polymerase also attaches to the start of one of the newly exposed template strands, and begins joining complementary RNA nucleotides to it.
What is the fourth step of transcription?
A pre mRNA molecule is formed
What is the fifth step of transcription?
pre-mRNA with introns transcribed. These are removed and the pre-mRNA modified to make mRNA.
The synthesised mRNA will then leave the nucleus through a nuclear pore.
What is the sixth step of transcriptions ?
Once the RNA polymerase has detached, the DNA can rewind, forming hydrogen bonds between its bases.
What are introns?
Non - coding regions of DNA
What are Extrons ?
Coding regions of DNA
What are the steps of translation ?
- mRNA attaches to a ribosome
- The ribosome moves along the mRNA reading the code. At the start codon, it begins making the protein
- For each codon on the mRNA, a tRNA with a matching anticodon brings the correct amino acid
- The amino acids are bonded together to form the protein
