Protein Synthesis Flashcards
What are the main points of transcription?
DNA helicase- to split the DNA
Makes mRNA
Uses RNA polymerase to join the free RNA nucleotides
What does DNA helicase do?
Unzip the double strand of DNA
What does RNA polymerase do?
Joins nucleotides
What forms between the bases?
Hydrogen bonds- complementary base pairing
What dos RNA polymerase join onto?
The start codon
What do activators do?
Control gene expression
What do repressors do?
Can turn transcription on and off
Where must RNA polymerase attach to the DNA?
Upstream of the transcription start site (the promoter)
What do transcription factors bind to?
DNA/enzme
What does RNA polymerase bind to?
The DNA and is transcribed
What shape is mRNA?
Linear
What is used in transcription?
mRNA
What is used in translation?
tRNA
What shape is tRNA?
Clover-leaf shape
Where do amino acids code on the tRNA molecule?
At the amino acid attachment site (at the top of the molecule)
Where do anti-codons bind on the tRNA molecule?
The bottom of the molecule
What shape is rRNA?
Sphere shape
Are introns coding or non-coding?
Non-coding
What enzyme removes the introns?
The spliceosomes
Where does DNA replication and transcription occur in?
The nucleus
DNA replication and transcription both form what bonds?
Phosphodiester bonds
What type of base pairing does DNA replication and transcription both use?
Complementary base pairing
Similarities between DNA replication and transcription?
Both involve DNA helicase
Both occur in the nucleus
Both strands are copied
Both form phosphodiester bonds
Both form H+ bonds
Both use complementary base pairing
Differences between DNA replication and transcription?
Transcription contains RNA polymerase- DNA replication uses DNA polymerase
Transcription only copies one strand- DNA replication copies both strands
Transcription uses RNA nucleotides (A,U,C,G)- transcription uses DNA nucleotides
mRNA is made as the end product in transcription- DNA is made as the end product in DNA replication
What is the copied strand in DNA replication called?
Pre-mRNA
Where does the mature mRNA exit the nucleus via?
The nuclear pore
What happens to the copied strand once it leaves the nucleus?
It is decoded at a ribosome which is found in the cytoplasm (translation)
What does each codon code for?
A particular amino acid which is brought to the ribosome by tRNA molecules
What does the anticodon on tRNA bind to?
The complementary codon on mRNA to ensure the correct amino acid is brought over
How are the amino acids joined together?
Using energy from ATP and an enzyme
What happens when a stop codon is reached?
Translation is terminated and the resulting amino acid chain folds into a protein
