Please note the first few pictures are the passage to the question I am inquiring about. The question can be found in the last image. Please read below for where my confusion is. I’m a little confused as to what the question is asking, and where to find the answer more specifically how will the changes affect the SDS- PAGE results? Also, what is the difference between 32p and 14p?
Passage 8 (Questions 38-43) Glycogen synthase catalyzes the lengthening of glycogen polymers through the addition of glucose. The reaction consists of transferring a glucosyl moiety from uridine diphosphate glucose (UDP- glucose, Figure 1) to the nonreducing end of the glycogen molecule along with the release of UDP. UDP-glucose is formed from the enzymatically-catalyzed reaction between glucose 1-phosphate and UTP. It was discovered that approximately one out of every 600-1500 glucose molecules in muscle glycogen contains phosphate groups covalently linked to the C2 and C3 positions as monoesters. It is hypothesized that glycogen synthase is responsible for the phosphorylation. OH HO HO & NH ОН O II Dono
ОН HO HO NH OH TO o ОН ОН Figure 1 The structure of UDP-glucose Lafora disease is a fatal progressive epilepsy that is characterized by the formation of deposits of sparsely branched, insoluble glycogen-like polymers called Lafora bodies (LBS). LBS contain a much larger amount of covalently-linked phosphate compared to normal glycogen. The abundance of phosphate has been linked to a mutation in the gene for laforin, a phosphatase specific to carbohydrates. In order to test if glycogen synthase is responsible for glycogen phosphorylation, Done
both UDP-[U-14C]glucose and [B-32P]UDP- glucose were incubated with muscle extracts from wild-type (WT) mice and mice lacking muscle glycogen synthase (MGSKO). The reaction products were separated by SDS-PAGE and visualized by autoradiography that detects the products of ß- decay (Figure 2). The data were normalized to account for the different decay rates. The samples were also treated with glucosidase, an enzyme that breaks down glycogen, and assayed in the same manner. WT MGSKO WT MGSK + + + 14c 32 Figure 2 SDS-PAGE analysis from muscle extracts visualized with either 14C or 32P radioactive decav (Note: The Done
Addition of laforin to the reaction mixtures used to generate the data in Figure 2 will result in: A. a decrease in the intensity of the band representing WT without glucosidase when visualized with 14C decay. B. an increase in the intensity of the band representing WT without glucosidase when visualized with 14C decay. C. a decrease in the intensity of the band representing WT without glucosidase when visualized with 32p decay. D. an increase in the intensity of the band representing WT without glucosidase when visualized with 32p decay. Done