2026 - BMS528 - Summer - Practice Exam 2 Flashcards

A set of vocabulary-style flashcards covering gene regulation, protein folding, RNA structure, and translation processes from the BMS528 Summer Practice Exam 2.

You have discovered a new protein. What is the first codon in this proteins mRNA?

AUG

Mutations in the wobble position of codons are usually silent i.e. they are not observed in the amino acids sequence of proteins. For which of the following amino acids would a wobble mutation in it's codon not be silent?

Tryptophan

"A set of genes regulated by a single promoter and operator sequence" is the definition of what type of gene regulation mechanism/structure

Operon

"A DNA change in which an amino acid codon is changed to a stop codon" is a description of what type of mutation?

Nonsense

In an inducible operon system, without an inducer, structural genes are:

not transcribed

Protein disulfide isomerase reduces disulfide bonds and is in the process:

Oxidized

In an inducible operon system, without an inducer, structural genes are

not transcribed

The macromolecular complex responsible for protein degradation is called:

Proteasome

Protein biochemists often use bacteria to express the proteins they are studying. They do this because they can easily culture large numbers of bacteria and thus express large quantities of protein. They can then extract and isolate their protein of interest for their studies. A common problem with this approach is that the protein of interest, once isolated, is often misfolded due to environmental differences between the bacterial cell environment and the native environment of the protein. Which of the following approches would you take to try and get the protein into it native form?

Denature the isolated protein then allow it to refold under its native conditions

You isolate two forms of helical nucleic acid, NA1 and NA2. You examine the backbone structure of each and notice that the phosphate gorups in NA1 are ~7 angstroms apart, while in NA2 the phposphates are 5.0 angstroms apart. Which of these nucleic acids is likely to be RNA?

NA2

You isolate two forms of helical nucleic acid, NA1 and NA2. You examine the backbone structure of each and notice that the phosphate groups in NA1 are ~7.0 angstroms apart, while in NA2 the phosphates are ~5.9 angstroms apart. What type of nucleic acid helix would you predict NA2 would form form?

A helix

Identify the following molecule:

5-methylcytosine

What type of bonds are crucial for basepairing in RNA stemloop stems?

Hydrogen

Proteins sample every possible thermodynamic conformation before finding the lowest energy state.

False

Except for the very first tRNA, all incoming aminoacyl-tRNA molecules are first placed into which site on the Ribosome?

A

UAA, UAG and UGA are all stop codons. What amino acid does the codon UAA

code for?

It does not encode an amino acid.

Translation termination is a process that requires:

GTP

Charging of a tRNA is the process by which an amino acid is attached to a tRNA. The amino acid is added where on the tRNA?

3' end

Select the option that best fits the blank in the statement below: The first step of tRNA charging is the __________ of Amino acids.

Adenylation

Identify the following molecule:

N6-methyladenosine

What position (number) within the ring is the arrow pointing to?

1

The protein motifs "helix-turn-helix" and "lecuine zipper" are commonly found in what type of protein?

Transcription factors

A human gene encodes for a protein that is 100 amino acids in length. The

gene itself has a 5' untranslated region consisting of 50 nucleotides, an

intron in the middle of the gene containing 50 nucelotides, and a 3' untranslated

region of 50 nucleotides. After transcription of the gene, in the final, mature

mRNA, approximately how many nucleotides are there between the start AUG

codon and the last stop codon?

300/303

Two RNA molecules you are studying have an almost identical cloverleaf structure, containing three hairpins. One difference however, is that RNA molecule X has fewer nucleotides in the loops of its hairpins than RNA molecule Y does. Which of the following properties would this likely confer upon RNA molecule Y?

More flexible loops

Amino acids are attached to the acceptor arm of the tRNA. What property of the

acceptor arms makes this possible?

The presence of free 2' and 3' hydroxyl groups

What position (number) within the base ring is the arrow pointing to?

1