Multiple Answers questions are similar to Multiple choice, except testers can choose more than one answer.  Mark the correct answer(s) by clicking the arrows to the left of the “Possible Answer”.   Unicorns are:

Matching questions give testers two columns and require them to match the term on the left side with the correct answer on the right side.  This also has an option to include distractors.

The molecule 2,3-biphosphoglycerate (2,3-BPG) regulates the oxygen binding affinity of hemoglobin. The graph below shows the oxygen binding curves for hemoglobin in the presence of 2,3-BPG both at normal levels (red, middle) and at high levels (green, right), as well as in the absence of 2,3-BPG (blue, left). The partial pressure of oxygen both in the lungs and in the tissues are indicated (in mmHg).  Blank #1: What type of effector is 2,3-BPG? (positive/negative, homotropic/heterotropic) Blank #2: How much oxygen (%) is delivered to the tissues by hemoglobin with normal levels of 2,3-BPG? Blank #3: How much oxygen (%) is delivered to the tissues by hemoglobin when there is no 2,3-BPG present? Blank #4: Compared to normal levels of 2,3-BPG, how much more/less oxygen (%) is delivered to the tissues when there is no 2,3-BPG? Your answer should state “xx% more/less oxygen is delivered to the tissues”. Blank #5: In addition to 2,3-BPG, name two other effectors (making sure you state whether you have higher or lower concentrations of that effector) that would shift the “normal” red binding curve of hemoglobin to the left (blue). Your answer should be something like: Higher/lower concentration of ____, higher/lower concentration of ____.

Trypsin and chymotrypsin are members of the family of serine proteases. They cleave peptide bonds at the C-terminal end of specific residues. The recognition of a particular residue (side chain specificity) is determined by the structure and properties of a binding pocket. For each of the enzymes above, describe the characteristics of the binding pocket needed to attract the side chain of the correct amino acid residue in the polypeptide chain to be cleaved. These characteristics are listed below. a) the size (long/short) and shape (narrow, wide), as well as  b) the polarity (hydrophobic/hydrophilic/type of charge (+/-) if present)   Blank #1: trypsin Blank #2: chymotrypsin

Find the inverse of the one-to-one function: f(x) =

Numbering of N in purines and pyrimidines (for reference).  Below are some nucleotides: Blank #1: Which of the nucleotide(s) above would be found in DNA? Answer with both the abbreviated and the full name.  If more than one answer is correct, list them separated by commas.  Blank #2: For the nucleotide in blank #1 name the three components that make it. Blank #3: For the nucleotide in blank #1, name the two types of bonds that join the three components.  Blank #4: How many hydrogen bonds would be established between the nitrogenous base in CMP and the nitrogenous base in GMP? Blank #5: What is the charge of CMP at physiological pH (7.4)? The two pKa values for the phosphate group are 0.8 and 6.3, and the pKa for N-3 is 4.5

Below is the catalytic triad of chymotrypsin. Match each statement to one of the three residues shown. 

Find the slope of the line that goes through the given points: (7, 8), (6, -4)

,.  A portion of the non-coding (“sense”) strand for a given gene has the sequence 5′-ACTGTCGCACAG-3′ Blank #1: How many hydrogen bonds can be established between the nitrogenous bases in the portion of the non-coding strand above and the nitrogenous bases in the complementary, coding strand?  Blank #2: What is the sequence of the complementary (coding) strand in DNA? Identify the 3′ and 5′ ends.  Blank #3: What is the sequence of the mRNA that would be produced during transcription from the coding strand? Identify the 3′ and 5′ ends.  Blank #4: What amino acid sequence does this code for?  Blank #5: The aminoacyl t-RNA synthase that catalyzes the condensation of methionine to the acceptor stem of a given t-RNA would recognize which anticodon in the t-RNA?

A hexapeptide that is part of a mouse hormone was hydrolyzed to give the following amino acids (in no particular order): Tyr (Y), Cys (C), Glu (E), Ile (I), Lys (K), Met (M).  a) two cycles of Edman degradation of the intact hexapeptide releases the PTH-amino acids below. Remember that the Edman reagent reacts with the N-terminus amino acid and cleaves it off as a cyclic structure (PTH), where only the R group of the amino acid is recognizable. b) cleaving the intact hexapeptide with cyanogen bromide yields Met and a pentapeptide c) treating the intact hexapeptide with trypsin yields a dipeptide, which contains Tyr and Glu, and a tetrapeptide d) when the intact hexapeptide is treated with carboxypeptidase A, a Tyr residue and a pentapeptide are produced.  Write the sequence of the hexapeptide in the blank below.