FIGURE 2.

¹³C NMR spectrum of MAG derived from hydrolyzed glycogen of a heart supplied with [U-¹³C₃]glycerol. The multiplets seen in the C4, C5, and C6 resonances but not in the C1, C2, and C3 resonances indicate that carbons originating in [U-¹³C₃]glycerol find their way only into the bottom half of glucosyl units of glycogen. The singlets detected in each glucosyl unit resonance reflect largely natural abundance levels of ¹³C. Q, doublet of doublets, or quartet, arising from coupling of C5 with both C4 and C6; S, singlet.