Liver cells were monitored for changes in metabolic enzymatic activity after exposure to glucagon.The enzymes that showed changes in activity were then analyzed to assess if they had been covalently modified.Which of the following results were likely observed?
A) Enzymes that showed lower activity were not phosphorylated.
B) Enzymes that showed higher activity were methylated.
C) Enzymes that showed altered activity (higher or lower) were phosphorylated.
D) Enzymes that showed altered activity (higher or lower) were methylated.

Question

Quizplus · Accepted Answer

Glucagon signaling typically leads to the activation of protein kinase A (PKA), which phosphorylates various metabolic enzymes, resulting in changes in enzymatic activity. Therefore, the enzymes that showed altered activity (higher or lower) were likely phosphorylated. Options A and B are incorrect as they suggest modifications other than phosphorylation, which is the main mechanism of regulation by glucagon.

Liver Cells Were Monitored for Changes in Metabolic Enzymatic Activity