Question

b. What is the role of the poly-U? 4.5 4 3.5 acs as a poly mer je E 2.5 c. What process did this experiment monitor? - control -poly-U 1.5 poly-U + ricin 0.5 d. Why is the background level of incorporation not zero? 0 10 20 30 Figure 2. Effect of ricin on polyphenylalanine synthesis. A cell free system was preincubated at 28 for 40 minutes in the absence of labelled compounds. Then 4 uCi of HC phenylalanine was added, and the system was divided into three equal samples One sample (A) was used as a control, another sample ( contained 100 pg of poly-U and a third sample (x) containec 100 μg of poly-U and 0.5 pg of ricin. The samples we incubated at 28°C and aliquots were removed as indicate and the acid-precipitatable radioactivity was determine Source: Redrawn from Figure 2 of Olsnes and Phl, 1972. What conclusion can be drawn from this experiment

Answer 1

C. This experiment monitors the acid precipitatable radioactivity of labelled compound.

D. The background incorporation level is not zero because there is always a small amount of phenylalanine is present in all the samples