ife evolved with 5 different nucleotide bases that are used in their equivalent of DNA, how many amino acids could be encoded by a 3-nucleotide codon?...

Question 1

1. If, on an exoplanet somewhere, life evolved with 5 different nucleotide bases that are used in their equivalent of DNA, how many amino acids could be encoded by a 3-nucleotide codon?
2. 61
3. 20
4. 25
5. 125

0.5 points  

1. If, on an exoplanet somewhere, life evolved with 5 different nucleotide bases that are used in their equivalent of DNA, what is the minimum codon size that could be used to uniquely encode all of Earth's 20 amino acids?
2. 1
3. 2
4. 3
5. 4

0.5 points  

1. In addition to ribosomes, mRNA, and tRNA, what else must you add to a cell-free reaction system in order for the mRNA to be translated?
2. ATP
3. GTP
4. All 4 RNA nucleotides
5. Heat

0.5 points  

1. Which of the following enzymes catalyzes peptide bond formation?
2. A ribosomal protein
3. An rRNA
4. tRNA
5. tRNA Synthetase

0.5 points  

1. Imagine that you synthesized mRNA molecule containing a random mix of A, U, and G nucleotides and translated it using purified ribosomes. Which of the following tRNA anti-codons is NOT needed to translate the mRNA in the previous question?
2. AUG
3. AAA
4. UCU
5. AUA

0.5 points  

1. A 3-base deletion in the AAUAAA sequence in the 3' untranslated region of an mRNA that eliminates the AAU, thereby preventing RNA Polymerase from polyadenylating the mRNA would have the effect of:
2. decreasing the number copies of the polypeptide that would be translated from this mRNA
3. decreasing the length of the encoded protein by one amino acid. This may or may not affect the protein's function because it is not a frameshift mutation
4. drastically altering the polypeptide sequence because it is a frameshift mutation.

0.5 points  

1. What would happen to a secreted protein (e.g. insulin) if you produced it from an mRNA missing the sequence encoding the signal peptide?
2. It would be properly secreted, though it might not fold correctly.
3. It would get translated in the cytoplasm and remain there.
4. It would get trapped in the ER.
5. It would get transported to the plasma membrane and become embedded there.

0.5 points  

1. What would you find encoded in the mRNA of the enzyme helicase?
2. A nuclear localization signal
3. A signal peptide
4. Neither of the above
5. Both of the above

0.5 points  

1. Which of the following is required for post-translational import?
2. A signal peptide
3. A signal recognition particle (SRP)
4. SRP receptor
5. All of the above
6. None of the above

0.5 points  

1. What is an advantage of a degenerate genetic code?
2. Mutations are more likely to alter proteins, increasing the rate of evolution.
3. Mutations are less likely to alter protein sequence, decreasing the chances that a mutation will have deleterious consequences to the organism.
4. It increases the number of different proteins that can be coded by each gene.
5. It decreases the total number of tRNAs that have to be made.