Bio Question Pack V2 #96

[kryptonxenon]

Colchicine most likely relieves gout symptoms through what mechanism?
A. Prevention of uric acid diffusion through cell membranes
B. Inhibition of leukocyte phagocytosis of uric acid crystals
C. Inhibition of uric acid formation
D. Maintenance of the pH optimum of PRPP synthetase

I thought the answer would be C. If phagocytosis is inhibited wouldn't the pain be worse?

Also what is the difference between synthase vs. synthetase vs. ligase?

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[theonlytycrane]

The first paragraph describes how phagocytosis of the uric acid crystals leads to the hyperactivity of the inflammatory cells. So inhibition of this process may relieve some pain. The uric acid crystals wouldn't be affected by a microtubule inhibitor, so the inhibition is likely on the leukocytes.

 

[kryptonxenon]

The first paragraph describes how phagocytosis of the uric acid crystals leads to the hyperactivity of the inflammatory cells. So inhibition of this process may relieve some pain. The uric acid crystals wouldn't be affected by a microtubule inhibitor, so the inhibition is likely on the leukocytes.

So too much inflammation = pain? Also not sure if you caught my other question: What is the difference between synthase vs. synthetase vs. ligase?

 

[theonlytycrane]

So too much inflammation = pain? Also not sure if you caught my other question: What is the difference between synthase vs. synthetase vs. ligase?

The last part of the passage says that a patient took colchicine and was relieved of some pain. Without it, leukocytes gobble up the uric acid crystals leading to inflammation. So less inflammation and pain kind of go together. Think about a sports injury or bee sting. The area swells as RBC / WBC are brought to the site for immunity and healing. The process can be painful as our body responds.

I don't have the best answer for the differences- all end with 'ase' though so we're talking enzymes. Ligase connects DNA strands together during DNA replication, and I've seen both synthase and synthetase for enzymes in Kreb's cycle like citrate synthase and succinyl-coa synthetase. I don't think we need to know the exact differences, just know they are enzymes and use the passage context to get an idea of what they might be doing.

 

[betterfuture]

So too much inflammation = pain? Also not sure if you caught my other question: What is the difference between synthase vs. synthetase vs. ligase?

Synthase helps catalyze reactions by joining together molecules and uses the help of H2O. Synthetases involve ATP as an energy source. I don't even think it has to be ATP. The reaction just needs to use some type of energy source. Ligases help catalyze addition reactions of large similar molecules using ATP. Ligases are synthetases.