Scenario 2 – “Yeast on Caffeine” (10 points) A bakery yeast…
Scenario 2 – “Yeast on Caffeine” (10 points) A bakery yeast strain grows poorly unless caffeine is added. Geneticists suspect a mutation in the PDE1 gene, which encodes a phosphodiesterase that terminates cAMP signaling. Normally, phosphodiesterase lowers cAMP levels, thereby [1] Researchers find the PDE1 promoter heavily methylated only in caffeine‑dependent yeast. This suggests [2] Which event happens to yeast PDE1 pre‑mRNA before export to the cytoplasm? [3] To clone the wild‑type PDE1 gene, scientists cut the gene and a plasmid with EcoRI (GAATTC). EcoRI creates sticky ends because it [4] Sequencing the mutant gene reveals an early stop codon. In Sanger sequencing, incorporation of a dideoxy‑GTP stops elongation because it [5]
Read DetailsScenario 1 – “Muscle‑Twitch Mice” (10 Points) A colony of la…
Scenario 1 – “Muscle‑Twitch Mice” (10 Points) A colony of lab mice has begun displaying sudden, short bursts of running whenever a loud sound occurs. Researchers discover a dominant allele T that encodes a hyperactive epinephrine receptor in skeletal‑muscle cells. Which change most directly explains the mice’s behavior? [1] Hyper‑activity of this receptor would first increase the activity of which enzyme inside the muscle cell? [2] To verify that the T allele produces a longer receptor protein, what step follows transcription of the T mRNA?[3] If skeletal‑muscle cells alone express the epinephrine‑receptor gene, which explanation is most consistent? [4] Researchers design primers flanking a 180 bp region that includes the T mutation. After PCR and agarose‑gel analysis they expect the mutant allele to show: [5]
Read DetailsUse the special form of Hess’s law and given ∆H°f of the rea…
Use the special form of Hess’s law and given ∆H°f of the reactants and products to calculate the heat for the reaction (∆H°rxn) of methane with oxygen: CH4 (g) + 2 O2(g) CO2(g) + 2 H2O(l) ∆H°f, methane (g) -74.60 kJ/mol ∆H°f, water (l) -285.8 kJ/mol ∆H°f, carbon dioxide (g) -393.5 kJ/mol
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