ch 40 Flashcards
(12 cards)
What are the 3 acts of protein synthesis?
: Initiation (setup), Elongation (build-up), and Termination (the dramatic finale).
What do the A, P, and E sites on the ribosome stand for?
A = Arrival (aminoacyl), P = Party (peptidyl), E = Exit (peace out, tRNA).
Where does peptide bond formation happen?
At the peptidyl transferase center in the ribosome the real kitchen of biochemistry.
How does the growing peptide chain jump between tRNAs?
From the P site tRNA to the A site tRNA protein pass-the-parcel style.
How does translation end?
Stop codons summon release factors that splash water to break the bond. No tRNAs allowed.
Which part of synthesis doesnt need extra energy?
The actual peptide bond formation its exergonic, baby.
Where do secretory proteins get made?
On the rough ER its like Amazon Prime for proteins: sorted and shipped
How do ribosomes know to dock at the ER?
The signal sequence on the nascent protein says VIP delivery, and synthesis pauses until docking
How do amino acids get attached to tRNA?
Aminoacyl-tRNA synthetases use ATP to swipe right on the correct amino acid-tRNA match
What makes the genetic code degenerate?
Multiple codons can code for the same amino acid redundancy is safety AND style.
Whats wobble pairing?
The third base in the codon plays fast and loose with pairing efficiency over fidelity.
What happens in elongation translocation?
EF-G uses GTP to shift everything one codon forward it’s a molecular conga line.
