Protein Synthesis Flashcards
(45 cards)
Protein is made outside of the nucleus at the ________.
ribosome
Define transcription
making of mRNA from DNA
messenger RNA is a copy of ___ that can leave the ________.
DNA; nucleus
RNA’s base pairs are read in sets of 3 called ______.
codons
The three stages of transcription are:
- Initiation
- Elongation
- Termination
Give an overview of the initiation stage
starts transcription
Give an overview of the elongation stage
lays down the mRNA nucleotides
Give an overview of the termination
finalizes the mRNA
Describe the promoter
the beginning of the DNA sequence to be copied
What enzyme attaches to the promoter?
RNA polymerase II
Describe the TATA Box
the promoter begins with a sequence of DNA that includes the base pairs T and A
What are transcription factors?
proteins that allow the RNA Polymerase II to bind to the promoter.
What is the transcription initiation complex
the promoter, RNA Polymerase II, and Transcription factors all combined and ready to start transcription
Describe RNA Polymerase
an enzyme that unwinds DNA and lays down RNA nucleotides
A _________ ____ caused the mRNA to be cut free from the DNA.
termination code
When the mRNA is cut from DNA, it is called ___-___ and it needs a few modifications
pre-mRNA
How is the 5’ end of pre-RNA altered
it receives a modified 5′ cap
How is the 3’ end of pre-RNA altered
it a gets a poly-A tail
Describe the 5’ cap
a modified guanine nucleotide with 3 phosphate groups
Describe the poly-A tail
several adenine nucleotides in a row (50+)
What is the purpose of modifying pre-RNA?
- allows mRNA to leave the nucleus
- protects mRNA from hydrolytic enzymes
- helps ribosomes attach to the 5′ end
Describe introns
sections that are cut out of the pre-mRNA
Describe exons
sections that are left in the finalized mRNA
What do spliceosomes do?
carry out RNA splicing
