Choose the statements that correctly describe the structure and function of proteasomes. a. The proteasome hydrolyzes the unfolded proteins to free amino acids, which are then recycled.
b. The 26S proteasome unit is composed of a 12S component and a 14S component.
c. One of the 19S regulatory particles cleaves ubiquitin from the protein.
d. Proteasomes would not be expected to use ATP to degrade small, unfolded peptides.
e. The proteolytic sites of the proteasome are located at the middle of the 20S core.
f. Proteasomes degrade proteins to small peptides.

Match the following terms describing electrical events with the correct phases of the cardiac cycle. the ventricular muscle cells depolarize at the start of this phase. during this phase, na+ entry through the funny channels causes the pacemaker potential of sa nodal cells to gradually become less negative until it reaches threshold. the ventricular muscle cells repolarize right before this phase. the cytosolic concentration of calcium in the contractile cells of the ventricle is highest during this phase. a. isovolumetric relaxation b. ventricular ejection c. isovolumetric contraction d. ventricular filling

When energy is used, atp molecules convert to adp molecules. this process is called

Which statement best explains why cells were observed in more detail using a compound microscope than a simple microscope? a compound microscope has greater magnification ability than a simple microscope. the compound microscope was invented before the simple microscope. a compound microscope is much easier to manufacture than a simple microscope. compound microscopes were more common than simple microscopes.