BIOS 3450 Unit 2 Practice Quiz

• Madeline Alissa Murdock took the BIOS 3450 Unit 2 Practice Quiz SP25 and received a score of 72.28 / 100 points.

Question 1

• EF-Tu promotes accuracy in translation by removing incorrectly matched tRNA from the A site of the ribosome.

Question 2

• Mutating a UGG codon to a UGA codon would be the most detrimental scenario.

Question 3

• For the spliceosome to recognize an intron for removal, the intron must have a 3' splice site, an Adenine branch point and a 5' splice site.

Question 4

• A fluorescent signal placed on a ribosome partaking in translation is expected to be seen in the Endoplasmic Reticulum in a eukaryotic cell.

Question 5

• Aminoacyl-tRNA synthetase catalyzes the addition of an amino acid to a tRNA.

Question 6

• MDR protein (ABC transporter) pump hydrolyzes two ATP molecules per transport cycle.

Question 7

• The Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) protein functions primarily as an ion channel rather than as an active transporter, unlike most ABC transporters.

Question 8

• The Na+ K+ pump transports 3 Na+ ions against their electrochemical gradient out of the cell
• The pump transports 2K+ against their electrochemical gradient into the cell.

Question 9

• Transporter E mediates primary active transport when transporting solutes in the directions indicated.

Question 10

• DNA is not part of the initiation complex of translation.
• RNA in cells is single-stranded
• RNA folds into a variety of structures
• RNA contains the base uracil
• RNA contains the sugar ribose

Question 11

• TFIID binds to the TATA box in the promoter region of DNA.

Question 12

• If the template strand of DNA has the sequence 5’GCCTACTG 3', the complementary RNA strand is 5' CAGUAGGC 3'.

Question 13

• Digestive enzymes are not able to get to the small intestine as a direct result of thick mucous secretions in the lung in cystic fibrosis

Question 14

• The 5' cap of a mRNA is a nucleotide.

Question 15

• The mediator allows proper communication between activator and general transcription factors and RNA Pol II.

Question 16

• The Na+-K+ ATPase, also known as the Na+-K+ pump, maintains high extracellular sodium and high intracellular potassium ion concentrations.
• Immediately after the pump hydrolyzes ATP, the pump changes conformation.

Question 17

• Neurons and white blood cells have different functions because all of the proteins found in a neuron are completely different from the proteins found in a white blood cell

Question 18

• If a new tRNA with an attached amino acid (AA #4) is unable to bind to the ribosome complex, a reason for this could be it has a damaged P site.
• Before a eukaryotic mRNA is exported from the nucleus, the ribosome does not bind to the mRNA
• In the initiation phase of translation, the small ribosomal subunit searches for the 5'-AUG-3' codon on the mRNA
• Arginine will be on the tRNA that is the first to bind to the A site of the ribosome
• Intronic sequences are removed from RNA molecules by the spliceosome
• The genetic code is redundant
• The correct order, starting with a correct anticodon-codon match is:
  • The rRNA (in the ribosome) closes tightly around the codon-anticodon match
  • Conformational change in the ribosome
  • GTP hydrolysis is triggered in EF-Tu
  • EF-Tu releases tRNA (with amino acid) so it can now be used in protein synthesis
• The C-terminal domain tail mediates the tight coupling between transcription elongation and RNA processing events
• A damaged A site could be a reason for a new tRNA with an attached amino acid (AA-tRNA) being unable to bind to the ribosome complex
• TFIID binds to the TATA box on the promoter of DNA
• The modified guanine nucleotide cap protects mRNA transcripts from digestion because it resists digestion from exonuclease due to 5'-5' phosphodiester linkage
• Methylation of a CpG island in the promoter of a gene would decrease the expression of a gene
• On the ribosome, the mRNA is read from 5' to 3' and the polypeptide chain is synthesized from N-terminus to C-terminus
• It is incorrect to say that the Poly A tail is used to set the reading frame of the mRNA during translation
• The intron forms the lariat; the 5' end is attached internally during pre-mRNA splicing
• The spliceosome is unique because the catalytic site for splicing reactions is snRNA
• The complementary RNA strand to the DNA template strand sequence 5'-CCG TAG ACA-3' is 5'-UGU CUA CGG-3'
• A nucleosome consist of DNA wrapped around a histone protein
• It is incorrect to say that the RNA Polymerase II adds nucleotides to the 5' end of growing RNA strand
• The regulatory transcription factor that binds to the enhancer of the gene determines gene expression in certain cell types
• The carboxyl end of the polypeptide chain is released from the P-site tRNA and joined to the free amino group of the amino acid linked to the A-site tRNA during elongation
• The Ca2+ ATPase in the Sarcoplasmic Reticulum moves Ca2+ ions from the cytosol to the sarcoplasmic reticulum lumen
• A silent mutation will not affect the resulting protein because the amino acid encoded remains the same
• In translation termination, stop codons are recognized by a terminating tRNA molecule
• A mutation in CFTR protein in lung epithelial cells prevents both Cl- ions and water from leaving lung epithelial cells causing thick mucus buildup outside cells
• Light is required to activate channelrhodopsins
• From high to low permeability: CO2, water, glucose, Na+
• Inactivation of voltage-gated Na+ channels is chiefly responsible for the limit of a neuron's repetitive firing rate
• Channel proteins in cellular membranes can only mediate passive transport
• It is incorrect to say that voltage-gated sodium ion channels are open during the repolarization phase of the action potential
• Glucose transport across intestinal cells would decrease if a drug inhibits Na+/K+ pump on the basal side of intestinal epithelial cells
• The pump transports three Na+ ions against their electrochemical gradient into the cell and transports two K+ ions against their electrochemical gradient out of the cell is incorrect regarding the Na+/K+ pump.
• DNP collapses the proton gradient by equalizing proton concentrations as an uncoupler to inhibit ATP synthesis
• V type pumps are responsible for the acidification of lysosomes
• Two Asparagines in the center of the pore prevent protons from passing through the channel in aquaporins
• A conformational change causes Ca2+ ions to aggregate in the Sarcoplasmic Reticulum lumen after the Ca²+ pump is in its ATP-bound, phosphorylated state
• Less salt is reabsorbed from sweat into sweat glands in persons with Cystic Fibrosis, is the reason a sweat test is used in diagnosing it
• Hyperpolarization is when the potential across an axon membrane is more negative than the normal resting potential
• In a Na+-driven glucose transporter:
  • Na+ gradient drives the movement of glucose against its concentration gradient
  • Binding of Na+ and glucose is cooperative
• This drug helps the CFTR protein reach the plasma membrane in order to function is true about Trikafta
• Most multipass membrane proteins in eukaryotic cells are made from transmembrane alpha helices
• The helices can slide past each other, allowing conformational changes in the protein that can open channels or transport solutes.
• Sanshool elevates the resting potential (to less negative values) and makes it easier to excite the neuron
• If peptidyl transferase is rendered non-functional due to a drug, then would Peptide bond formation is impaired
• H₂O diffuses in faster than glucose of sodium across a membrane