Packet I: Bonus 18
Dahlquist and coworkers alternatively proposed that beta-glucosidase and this other enzyme catalyzed reactions by covalent substitution, as evidenced from secondary kinetic isotope effects. For 10 points each:
[10m] Name this enzyme, whose rate-determining step is the formation of an oxo-carbenium intermediate in the Phillips mechanism. Hen egg whites are rich in this enzyme, which digests microbial peptidoglycans.
ANSWER: lysozyme [accept muramidase or N-acetylmuramide glycanhydrolase]
[10h] Several Bacillus enzymes remove this chemical group from glucosamine and muramic acid to confer resistance to lysozyme. This group is added to lysine residues by the eukaryotic p300/CBP and MYST family of proteins.
ANSWER: acetyl groups [accept N-acetyl groups; accept -COCH3 or -CH3CO; prompt on acyl groups; prompt on carbonyl groups]
[10e] Lysozymes also have limited cross-reactivity against this compound, which is hydrolyzed by a “human” enzyme often linked to household allergies. Arthropod exoskeletons are primarily composed of this compound.
ANSWER: chitin
<AL, Chemistry> | Packet I - McGill B, UCLA A, Michigan B, Georgia Tech C, Southampton B
| Heard | PPB | E % | M % | H % |
|---|---|---|---|---|
| 42 | 11.67 | 88% | 21% | 7% |
Conversion
| Team | Opponent | Part 1 | Part 2 | Part 3 | Total | Parts |
|---|---|---|---|---|---|---|
| Columbia B | NYU A | 0 | 0 | 10 | 10 | E |
| Columbia C | Georgetown | 0 | 0 | 10 | 10 | E |
| Maryland A | Columbia A | 0 | 0 | 10 | 10 | E |
| Maryland B | Vassar | 0 | 0 | 10 | 10 | E |
| NYU B | Johns Hopkins A | 0 | 0 | 10 | 10 | E |
| NYU C | Johns Hopkins B | 0 | 0 | 10 | 10 | E |
| Rutgers A | Rutgers B | 10 | 0 | 10 | 20 | ME |
Summary
| Tournament | Edition | Match | Heard | PPB | E % | M % | H % |
|---|---|---|---|---|---|---|---|
| California (North) | Main Site | ✓ | 3 | 16.67 | 100% | 33% | 33% |
| Canada | Main Site | ✓ | 1 | 10.00 | 100% | 0% | 0% |
| Florida | Main Site | ✓ | 1 | 20.00 | 100% | 100% | 0% |
| Lower Mid-Atlantic | Main Site | ✓ | 4 | 15.00 | 100% | 50% | 0% |
| Midwest | Main Site | ✓ | 5 | 10.00 | 80% | 20% | 0% |
| Northeast | Main Site | ✓ | 4 | 15.00 | 100% | 25% | 25% |
| Overflow | Main Site | ✓ | 3 | 6.67 | 33% | 0% | 33% |
| South Central | Main Site | ✓ | 2 | 10.00 | 100% | 0% | 0% |
| Southeast | Main Site | ✓ | 6 | 11.67 | 100% | 17% | 0% |
| UK | Main Site | ✓ | 4 | 7.50 | 50% | 25% | 0% |
| Upper Mid-Atlantic | Main Site | ✓ | 7 | 11.43 | 100% | 14% | 0% |
| Upstate NY | Main Site | ✓ | 2 | 10.00 | 100% | 0% | 0% |