Mechanism Of Protein Synthesis Flashcards
Describe the structure of tRNA
80 nucleotides long
Single stranded but base pairs form within the chain
Clover leaf
Anticodon at one end
What is each tRNA specific for?
An amino acid
What determines the tRNA amino acid carried?
Its anticodon
What are tRNAs?
Adaptors
How is an amino acid attached to tRNA
ATP hydrolysed and amino acid joined to AMP
Correct tRNA bonds and amino acid transferee from AMP to tRNA
How many AA codons are there?
61 +3stop
How many tRNAs are there!
40-45
What the ribosome made of?
RNA and protein
What’s the role of ribosome in protein synthesis?
Bind mRBA and amino actyl-tRNA
Catalysed stepwise formation of peptide bonds
What are the 3 stages of protein synthesis?
Initiation
Elongation
Termination
What is peptide bond formation catalysed by?
Peptidyl transferase
What is the role of mRNA?
Take genetic info from DNA to a ribosome
What is the role of rRNA?
building block for ribosomes
What are the stop codon?
UGA UAA UAG
What is the start codon?
AUG (methionine)
What happens in the initiation process?
Small subunits binds mRNA and initiator amino actyl.tRNA then large subunits binds
What happens in the elongation process?
Peptide bonds are formed as the ribosome moves along the mRNA
What happens in the termination process?
A stop codon enters A site and protein is released
How does prokaryotic and eukaryotic cells differ in protein synthesis?
E:
Nuclear membrane
MRNA transported to the cytoplasm
Protein trafficked to correct site
P:
No nuclear membrane
Proteins diffuse through cytoplasm
Coupled transcription and translation
