Why is ubiquitin nicknamed the "doom tag"?
a. When ubiquitin binds to a target protein, the ubiquitin enzyme degrades the protein.
b. When ubiquitin binds to a target protein, the complex is sent to the proteasome and degraded.
c. If a cell is deficient in ubiquitin, the cell will die.
d. High levels of ubiquitin in a cell cause the cell to destroy vital proteins, leading to premature cell death.
e. Ubiquitin binds to ribosomes and prevents them from translating proteins necessary for cell survival.
ANSWER: b
You might also like to view...
Until the discovery of ________, enzymes were the only recognized biological molecules that were catalytic.
Fill in the blank(s) with the appropriate word(s).
Some drugs are now being delivered into cells through liposomes, where the drug is surrounded by a phospholipid bilayer. How do the drugs enter into the cell?
A. The drug destroys the liposome and is transported via diffusion into the cell. B. The liposome cuts a hole in the cell and injects the drug into the cell. C. The liposome fuses with the phospholipid bilayer of the cell. D. Protein channels on the cell surface transport the liposomes into the cell.
In the absence of oxygen, _____ reactions occur
Fill in the blank(s) with the appropriate word(s).
Two species of tree frogs occupy different elevations in the canopy of a rain forest. If these frogs with strikingly different patterns of coloration but similar patterns of activity are brought together, they can produce offspring that survive to adulthood and can then mate successfully with individuals of either species. What keeps these frogs recognizably distinct?
a. Lack of hybrid fertility b. Habitat isolation c. Temporal isolation d. Mechanical isolation e. Lack of hybrid viability