Lecture 9 Flashcards
(12 cards)
While RNA is translated from ___’ to ___’, the resultant protein is generated from its ____ terminus to its ____ terminus.
5’
3’
Amino
Caroxy
____ is the start codon sequence (but also doubles as Met codon), and the three stop codon sequences are:
___
___
___
AUG
UAA
UAG
UGA
The codons for protein are considered _____, meaning there are multiple codons that code for the same amino acid.
Degenerate (or redundant)
______ mutations, which would result in a shortened protein product, often produce little or no protein due to ____ ____ ____, a process by which the cell recognizes trunkated proteins and degrades them.
Nonsense
Nonsense Mediated Decay
A _____ mutation is one in which a stop codon is changed and the resultant protein product is lengthened.
Suppressor
Eukaryotic ribosomes (____S overall) are comprised of a ____S subunit and a _____S subunit. Prokaryotic ribosomes (____S overall) are comprised of a ____S subunit and a ____S subunit. The larger eukaryotic subunit is comprised of ____S RNA, 5.8S RNA, and 5S RNA components. The smaller Prokaryotic subunit is comprised of the ____S RNA component.
80S
60S
40S
70S
50S
30S
28S RNA
16S RNA
______ bonds are formed on and by the large ribosomal subunit, the Peptidyl transferase activity is facilitated by _____ (not protein.) The AA chain must grow to ____-____ AAs in length before it “pokes” out of the ribosome into the cytosol.
Peptide
rRNA
40-50 AAs
_______ is the term that describes the fact that eukaryotic mRNA codes for 1 protein, while ______ is the term that describes the fact that prokaryotic mRNA codes for multiple proteins.
Monocistronic
Polycistronic
The 3’ end of tRNA ends with the nucleotide sequence __ __ __.
CCA
______, an antibiotic, inhibits IletRNA synthase in bacteria.
Mupirocin
The formation of aminoacyl-tRNA occurs in 2 steps:
- The AA is activated by reacting with ____, forming aminoacyl-____ via the enzyme aminoacyl-tRNA ______.
- The activated AA is transferred to tRNA, esterified onto the ___ (nucleotide) at the 3’ end of the tRNA via the enzyme pyro_______.
Keep in mind this multi-step process allows for proofreading.
ATP
aminoacyl-AMP
aminoacyl-tRNA synthase
A
pyrophosphate
There are 2 different tRNAs for Met, which should make sense given that it can serve as the initiator AA (coded by start codon) and can also be a “normal” internal Met within the AA sequence. The former requires F-Met-tRNA ___ (in prokaryotes, or ___ in eukaryotes.) The internal Met requires Met-tRNA ___ in both prokaryotes and eukaryotes.
F-Met-tRNA F –> Pros
F-Met-tRNA I –> Eus
F-Met-tRNA M
