Test 7 - Lecture 5 Flashcards
When mRNA meets in a ribosome (rRNA), what can occur? (know the information discussed on chapter fifteen slide twenty-one)
The mRNA molecule will bind to an rRNA molecule within a ribosome
The key translation steps are carried out by ____________ since they are responsible for binding the certain three-nucleotide sequence with the appropriate amino acid. Fill in the blank.
Activating enzymes
One type of activating enzyme used during the translation process is called aminoacyl-tRNA synthase. What is its function?
Brings everything together and allows the process of translation to occur, and will become attached to specific amino acids
Within your cells, there are similar quantities of aminoacyl-tRNA synthase and amino acids. What is that number?
20 of each (1 for each of the 20 types of amino acids)
For three of the sixty-four codons known (shown on your codon chart), there exists no tRNA with a complementary anticodon, these are known as ______________. Fill in the blank.
Nonsense codons
In prokaryotes and eukaryotes, polypeptide synthesis (translation) begins with the formation of an initiation complex. What components make up this initiation complex?
The rRNA ribosome inside it is inserted the MRNA and it’s going to have specific sites where it will attach the tRNA
Be able to describe what is occurring during this picture of the initiation stage of translation and also be able to know the different parts (as discussed in class).
N/A (chapter 15 slide 24)
What is the abbreviation of the first amino acid placed within prokaryotes within the ribosome to begin the translation process?
tRNA ^fMET
Regarding the process of translation, is the function of the initiation factors used during the first process of initiation?
Yes
Which statement describes the difference between what occurs at the P, A, and E sites of a ribosome?
P: Where the peptide bond forms, first location in which the tRNA Is attached
A: Where successive amino acid barring tRNA will bind
E: Where empty tRNA will exit the ribosome so they can pick up more amino acids within the cytoplasm
In prokaryotes (and most eukaryotes), the beginning of each mRNA is marked by a ____________ complementary to one of the rRNA molecules on the ribosome, making sure it will be read from the beginning. Fill in the blank.
Leader sequence
Which statement does not describe a difference between the initiation stage of translation in eukaryotes verses prokaryotes? (Listed are differences between the two)
Prokaryotes: Often have several genes within a single mRNA transcript, initiating amino acid is tRNA^fMET, initiating complex is more complex
Eukaryotes: Transcribe one gene at a time (for every genes you have it’s own mRNA), initiating amino acid is tRNA^MET (THERE IS NO F), initiating complex is more simple
Which statement describes what occurs during the elongation stage of translation in prokaryotes and eukaryotes? (know the different steps we discussed in class with the drawings on the board with the A, P, and E sites)
The large ribosomal subunit binds exposing the MRNA codon adjacent to the initiating you know AUG you started with during the initiation stage, and it positions it for the interaction with another amino acid bearing tRNA molecule
Regarding the process of translation, what is the function of elongation factors?
Assist in binding to the exposed mRNA codon at the A site
Which statement describes translocation which takes place during the elongation phase of translation?
A tRNA attaches to the A site and elongation factors will “trade off” with the P site that will exit out of the E, and the tRNA will take whatever is at the P site and the empty one that was originally at the P site exists the E site (I don’t know how else to better explain this)
