Does the presence of introns/exons in eukaryotic cells provide more potential diversity in gene products (proteins) than is possible in prokaryotic cells?
A. It doesn't-this is a trick question. There's the same potential for gene products (proteins) in a bacterium with 1,000 genes as there is in a eukaryotic cell with 1,000 genes.
B. It does-each exon and each intron could be used individually and discretely to make agene product (protein). Since bacteria lack these, they will have less ability to create different proteins.
C. It does-exons/introns can be spliced together in different ways post-transcription to yield different mRNAs (and therefore, different proteins). Bacteria lack this system, so the gene you transcribe is translated into the only protein you'll end up getting.
D. It does-exons/introns can be spliced together in different ways at the DNA levelto eventually yield different mRNAs (and therefore, different proteins). Bacteria lack this system, so the gene you transcribe is translated into the only protein you'll end up getting.
A graduate student is trying to isolate bacterial mRNA for an enzyme that will degrade trinitrotoluene (TNT).
She's frustrated to find that the enzyme isn't produced when the bacterium in question is grown on nutrient agar. What might she do to solve the problem and obtain the mRNA?
A. Add nitrogen and toluene to the agar to drive up synthesis of TNT.
B. Add TNT to the agar-this will drive synthesis of the enzyme to degrade it, leading to production of the mRNA the student is looking for.
C. Remove glucose from the agar-this will cause the bacteria to shift to other compounds for their energy purposes.
D. Remove all sugars from the agar-this will cause the bacteria to shift to other compounds for their energy purposes.
E. Add TNT to the agar-this will drive synthesis of the enzyme to degrade it, leading to production of the mRNA the student is looking for AND remove all sugars from the agar-this will cause the bacteria to shift to other compounds for their energy purposes.
Why is it a good idea for a bacterial cell to be able to utilize glucose FIRST as an energy source (until it's used up), THEN switch to lactose?
A. Glucose is an easier compound to break down and obtain energy from than lactose.
B. Lactose cannot be used by bacterial cells as an energy source.
C. It's about conservation of energy-why expend the energy to make the extra enzymes for breaking down lactose when glucose is right there and doesn't need the extra enzymes for breakdown.
D. Glucose provides 10x as much energy when broken down as lactose.
E.
Glucose is no easier compound to break down and obtain energy from than lactose AND It's about conservation of energy-why expend the energy to make the extra enzymes for breaking down lactose when glucose is right there and doesn't need the extra enzymes for breakdown.
A drug that inhibits the activity of bacterial DNA gyrase ______ be a good antibiotic because _______.
A. would; it would inhibit all DNA synthesis
B. would NOT; it would inhibit all DNA synthesis, even our own cell's DNA synthesis
C. would; it would selectively inhibit bacterial DNA synthesis due to differences between bacterial/human gyrase
D. would NOT; the DNA replication machinery could still function, even with impaired DNA gyrase enzyme
Ribozymes are non-protein molecules with catalytic activity.
Indicate whether this statement is true or false.
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