Refer to the table below. The table summarizes results of experiments using whole cells.Cells were either incubated without an enzyme (control) or incubated with an enzyme.Proteases degrade proteins, and glycosidases degrade oligosaccharides.Which hypothesis is supported by these results?
A) Receptors for signal transduction pathways 1 and 2 bind the same ligands.
B) Receptors for signal transduction pathways 1 and 2 bind ligands that recognize glycoproteins.
C) Receptors for signal transduction pathways 1 and 2 bind ligands that recognize nonglycosylated proteins.
D) Pathway 1 involves a ligand that recognizes a nonglycosylated protein receptor, and pathway 2 involves a ligand that recognizes a glycoprotein receptor.
E) Pathway 1 involves a ligand that recognizes a glycoprotein receptor, and pathway 2 involves a ligand that recognizes a nonglycosylated protein receptor.

Question

Refer to the table below.  The table summarizes results of experiments using whole cells.Cells were either incubated without an enzyme (control) or incubated with an enzyme.Proteases degrade proteins, and glycosidases degrade oligosaccharides.Which hypothesis is supported by these results?
A) Receptors for signal transduction pathways 1 and 2 bind the same ligands. 
B) Receptors for signal transduction pathways 1 and 2 bind ligands that recognize glycoproteins. 
C) Receptors for signal transduction pathways 1 and 2 bind ligands that recognize nonglycosylated proteins. 
D) Pathway 1 involves a ligand that recognizes a nonglycosylated protein receptor, and pathway 2 involves a ligand that recognizes a glycoprotein receptor. 
E) Pathway 1 involves a ligand that recognizes a glycoprotein receptor, and pathway 2 involves a ligand that recognizes a nonglycosylated protein receptor.

Quizplus · Accepted Answer

The table shows that pathway 1 is inhibited by a protease and pathway 2 is inhibited by a glycosidase. This suggests that the ligand for pathway 1 recognizes a nonglycosylated protein receptor (which would be sensitive to protease degradation) while the ligand for pathway 2 recognizes a glycoprotein receptor (which would be sensitive to glycosidase degradation), as glycosylation is a common modification for proteins to become glycoproteins. Therefore, choice D is the best answer.

Refer to the Table Below