Here are some things you missed on the quiz and we think you should review.
Degradation of p21 implies that the concentration of p21 in its active form goes down. The diagram shows that p21 has a negative influence on CDK2. In other words, when p21 is high, CDK2 goes low. But in our instance, p21 is low (degraded) so this allows CDK2 to rise unchecked.
On the Surface: In the previous question, we established that the enzyme argininosuccinase must be functional for both strains and that means that argH is not defective (no mutation) for either P or Q. Thus any answer choice suggesting an argH mutation is incorrect.
On the Surface: Dialysis only refers to the transfer of the solute (diffusion), while the transfer of the solvent is called osmosis.
Going Deeper: Diffusion is the movement of a substance down its concentration gradient (from a region of high concentration to one of lower concentration). This is the process that must be occurring in the dialyser to remove toxins from the blood (because the dialysate, logically, would have no toxins so the toxins defuse out of the blood into the dialysate).
Protein phosphorylation is an important regulation of protein activity and function. Upon phosphorylation, a phosphate moiety is covalently attached to a hydroxyl (-OH) group of any of the three amino acids: Tyrosine (Y), Threonine (T) or Serine (S), which are the only 3 amino acids with a side chain containing hydroxyl.
Symbolic interactionists observe how people relate to things based on the meanings those things have for them. These meanings are created through social interaction and can be interpreted differently. For instance, people can meet to ‘have a coffee’ but are not obliged to actually consume the drink.