Fentanyl is an analgesic narcotic (opioid) drug. Its pKa = 8.3. *** a) Is fentanyl a weak acid or a weak base? *** b) At what buffer pH will the concentration of the drug and its conjugate form be equal?  *** c) The conjugate form of this drug would be: (e.g. Drug-COO- or Drug-NH+) *** d) How would the sodium salt of this drug be prepared? *** e) True or False: The carbon labeled with an (*) is chiral.  

Consider the structure of Vitamin A shown here. Select only the TRUE statement(s). (select all that apply…)

Select the amino acid(s) that contain an UN-IONIZABLE SIDE CHAIN (under physiological conditions)? (select all that apply)

Identify the amino acid(s) with a side chain that participates primarily in hydrophobic interactions  at physiological pH (7.4). (select all that apply)

What is the ratio of ANION to CATION for the drug below?   (enter #:#) What is the ratio of CATION to ANION for the drug below? (enter #:#)  

Select the amino acid(s) that contain a NON-POLAR SIDE CHAIN? (select all that apply)

Identify the amino acid(s) with a side chain that behaves as a BASE at physiological pH (7.4).  (select all that apply)

Consider the binding site within the muscarinic receptor where the endogenous neurotransmitter Acetylcholine binds. If the structure of Acetylcholine were redrawn properly within the active site, match the functional groups (1-6) to the locations in the binding site (A-F) where they would interact. (hint: rotate, twist, flip, turn the molecule as needed…expand combined functional groups as necessary). Functional Group # Binding Site Location (1) methyl group ? (2) oxygen in carbonyl between (A) and (B) (3) oxygen in ester ? (4) two-carbon spacer between (E) and (F) (5) quaternary amine ? (6) three methyl groups ?   note: Tyr616 has an -OH side chain

There are 35 multiple choice/short answer/fill in the blank (2pts ea) in this section of the exam.

GCHEM RECALL! Barium sulfate (BaSO4) is utilized in “barium swallow milkshakes” prior to taking x-rays of the digestive tract.  (note: when typing in chemical equations, don’t worry about formatting subscripts, for example BaSO4 = BaSO4 but use parenthesis as needed, for example Na3(PO4) = Na3(PO4) ) 2pt *** a) Write the balanced chemical equation describing how you would prepare BaSO4 from two aqueous solutions resulting in a BaSO4(s) precipitate.   (your answer should be in the format of reactants —> products) 2pt *** b) Classify your reaction for blank1 (e.g. neutralization, double replacement, single replacement, etc.) and explain your choice. 1pt *** c) Write an balanced equation for when CaCO3 (the main component in TUMS antacid) reacts with stomach acid, HCl