2. Functions and Dysfunction of Protein Processing Flashcards
What is a Missense mutation?
A mutation that changes a single amino acid. May do nothing, or change the protien entirely.
What is a Nonsense mutation?
A mutation that changes a codon into a stop codon.
(This is also caused a null mutation)
You think you can stop? Nonsense!
What is a Frameshift mutation?
When a nucleotide is deleted or added, causing all the others to be wrong.
Like when you accidentally skip a bubble on a scantron and get a 3% on a test
What is a silent mutation?
A mutation that does not change the resulting amino acid sequence.
Sickle Cell Anemia comes from what kind of mutation?
Missense.
In Sickle Cell Anemia, what amino acid is substituted for which other amino acid?
Glutamate (Negative charge and Hydrophillic) becomes Valine (hydrophobic)
In Duchenne’s Muscular Dystrophy - what sort of mutation is found?
Frame shift due to deletion, either out of frame (Severe) or in-frame (less severe)
What gene has deletions in Duchenne Muscular Dystrophy?
The dystropin gene.
What terminal region of tRNA binds the amino acid?
The 3’ CCA Terminal Region
What enzyme serves to “activate” an Amino Acid to tRNA, and helps to ensure the fidelity of the genetic code?
Aminoacyl tRNA Synthetase
For Prokaryotic Ribosomes
What is the total Svedberg unit for the entire size?
For the large portion?
For the small portion?
Prokaryotes are 70S total
The large subunit is 50S
The small unit is 30S
For Eukaryotic Ribosomes
What is the total Svedberg unit for the entire size?
For the large portion?
For the small portion?
Eukaryotes are 80S total
The large subunit is 60S
The small subunit is 40S
In which direction does Translation occur?
5’ to 3’
Same as DNA replication
What is the initiation codon, and what does it code for?
AUG, Methionine
What high energy compound is hydrolysed to help with loading of aminoacyl tRNA?
GTP
What enzyme attaches the second peptide to the first, releasing it from the tRNA?
Peptidyl Transferase
Where does the energy for peptide transfer come from?
From the high energy bond between the amino acid and tRNA.
What binds to stop codons?
Release Factors
(Not any tRNA / amino acid)
What sort of bond is cleaved by release factor, and where is it located?
Ester Bond
Between the C terminus of the polypeptide and the tRNA’s CCA terminal region.
When all is said and done, what dissociates the entire ribosomal complex?
GTP
In which subunit does peptidyl transferase activity occur?
The large subunit, for both prokaryotes and eukaryotes.