Unit 15 Genetic and translation Flashcards
in what kind of cell would you find an mRNA closed loop structure?
Eukaryotic
In bacteria, a formylated methionine can be found
- at the initiation position.
In bacterial cells, the first AUG encodes a modified type of methionine, N-formylmethionine; thus, all proteins in bacteria initially begin with this amino acid, but its formyl group may be removed after the protein has been synthesized.
Many antibiotics target the process of _____ because it is essential to the life of bacteria and differs significantly between bacterial and eukaryotic cells.
translation
You are investigating whether the genetic code is overlapping or nonoverlapping. You translate a set of three codons. If the genetic code were overlapping, how many amino acids would you expect to produce?
seven
An overlapping code would be one in which a single nucleotide might be included in more than one codon.
All these components are necessary for the initiation of translation in a bacterial cell, EXCEPT
release factor 1
A nontemplate strand of bacterial DNA has this base sequence. What amino acid sequence will be encoded by this sequence? 5’–ATGATACTAAGGCCC–3’
UACU AUG AUU CCG GG
Which of these is NOT an example of an amino acid that can result from a degenerate genetic code?
tryptophan
in your bacterial translation experiment, you notice that you keep producing proteins with incorrect amino acids, based on the sequence of the mRNA. What is one possible reason you are seeing this?
The ribosome you are using is defective in its proofreading function.
After translocation, the ribosome checks the interaction between the mRNA and the tRNA in the P site. If the wrong tRNA was added, the alignment between the mRNA and tRNA will be incorrect, triggering premature termination of translation.
consider this mRNA sequence that is downstream from the start codon and refer to Figure 15-10:
5’-CGUAUCAACGUA-3’.
Which of the sequences of amino acids shown could NOT result from the translation of this section?
-Met-Gln-Leu-Cys-
The mRNA sequence does not contain the codon AUG, which codes for methionine.
which step in the initiation of translation in bacteria requires energy
the binding of the charged fMet-tRNA1fMet to the initiation codon
How does the human pathogen diphtheria disrupt translation?
by preventing eEF2 from facilitating the translocation of the ribosome down the mRNA
What is the correct order of events in the elongation process?
an anticodon on a charged tRNA binds the codon on the mRNA in the A site, GTP is cleaved to form GDP, an empty tRNA shifts from the E site to the cytoplasm
Which element is not involved in eukaryotic translation initiation?
fMet-tRNA1fMet
This is the amino acid that is bound to the initiator tRNA
