Lecture 29 Flashcards
protein synthesis
Translation
the reading of the mRNA to turn them into protiens
Why is protein synthesis important?
- learn the fundamental process to produce protein
- how to target with antibodies
how much energy does translation use?
90% of the chemical energy of a cell
what is mRNA
the message between gene ad protien, has the message that is read by the tRNA
what is tRNA
the key adapter that reads the genetic code and brings amino acids to build the polypeptide
what is rRNA
holds the polypeptide in the right position for the tRNA
what is tRNA made up of
shaped like a 3 leaf clover and
modified bases like
- ribothymidine
- dihyrouridine
- wyosine
- psedouridine
has an anticodon loop that antiparallel with mRNA
how is tRNA binding with mRNA
tRNA sysnthetases couples the amnio acids to the 3’ end of tRNA. Each tRNA bind to a specific amino acid.
anticodon
it is on the tRNA to Watson crick pair on the mRNA to read it.
the genetic code
it matches the mRNA and the coding strand of DNA
(except it has U)
it is degenerate so more than one codon is associated with one amino acid
open reading frame
a long sequence without any stop codons
truncated protien
when a protein isn’t folded properly
frameshift
when an insertion of deletion occurs and shifts each codon down by one. this can change the whole protein
What are the 4 steps of protein synthesis
1) initiation
2) elongation
3) termination
4) ribosome recycling
what is the makeup of ribosomes in prokaryotes
80S = 40S (small) + 60S (large)
what is the makeup of ribosomes in eukaryotes
70S = 50S (large) + 30S (small)
what does the small subunit do?
provides a framework so the tRNA can match the codons of the mRNA.
what does the large subunit do?
catalyzes the peptide formation
what does the “S” mean in the ribosomal subunit
sedimentation rate = measuring the size using a centrifuge
what are the 4 binding spots on the ribosome?
1) the A site, called aminoacyl-tRNA
2) the P site called peptide-tRNA
3) the E site, called EXIT
4) the mRNA binding site
