Question
To begin one process, one of these proteins is phosphorylated by GCN2, HRI, and protein kinase R. For 10 points each:
[10h] What proteins include the only protein that has the nonstandard amino acid hypusine, and another labelled “4A” that is the original DEAD-box helicase? PERK phosphorylates the alpha subunit of one of these proteins to halt the cell cycle and activate the unfolded protein response.
ANSWER: eukaryotic initiation factors [or eIFs; accept eIF2 or eIF4A or eIF5A or eukaryotic initiation factor 2 or eukaryotic initiation factor 5A or eukaryotic initiation factor 4A]
[10e] eIF2 is part of a complex that binds to the 40S subunit to begin translation in these structures, which synthesize proteins from mRNA transcripts.
ANSWER: ribosomes
[10m] The initiator tRNA and eIF2 form a tertiary complex with this molecule at the start of translation. Hydrolysis of this molecule at the head of tubulin heterodimers leads to a “catastrophe” that causes dynamic instability.
ANSWER: GTP [or guanosine triphosphate]
<Cambridge A, Biology>
Summary
| California | 2025-02-01 | Y | 3 | 20.00 | 100% | 67% | 33% |
| Lower Mid-Atlantic | 2025-02-01 | Y | 6 | 8.33 | 83% | 0% | 0% |
| Midwest | 2025-02-01 | Y | 6 | 15.00 | 83% | 50% | 17% |
| Northeast | 2025-02-01 | Y | 5 | 12.00 | 80% | 40% | 0% |
| Pacific Northwest | 2025-02-01 | Y | 2 | 5.00 | 50% | 0% | 0% |
| South Central | 2025-02-01 | Y | 2 | 10.00 | 100% | 0% | 0% |
| Southeast | 2025-02-01 | Y | 1 | 10.00 | 100% | 0% | 0% |
| Upper Mid-Atlantic | 2025-02-01 | Y | 8 | 8.75 | 75% | 13% | 0% |
Data
| Harvard A | BU | 0 | 0 | 0 | 0 |
| MIT A | Brandeis B | 0 | 10 | 10 | 20 |
| Brown A | Harvard B | 0 | 10 | 10 | 20 |
| Brandeis A | Dartmouth A | 0 | 10 | 0 | 10 |
| Tufts A | UMass Boston | 0 | 10 | 0 | 10 |