Question

question 6
2 pts
signal transduction pathways that include a phosphorylation cascade ...
are generally initiated by a phosphorylase enzyme.
are propagated by steriod hormone receptors.
cause a structural change in each phosphorylated protein.
are generally inactivated by a kinase enzyme.

Explanation:

• Phosphorylation cascades involve a series of protein - protein interactions. When a protein is phosphorylated (a phosphate group is added), it undergoes a structural change. This structural change is crucial for its function in the signaling pathway.
• Phosphorylation cascades are initiated by kinases (not phosphorylase enzymes). Kinases add phosphate groups, while phosphorylase enzymes typically remove phosphate groups in other metabolic contexts (like glycogen breakdown).
• Steroid hormone receptors are not directly involved in phosphorylation cascades. Steroid hormones usually act by binding to intracellular receptors and regulating gene expression.
• Kinase enzymes are involved in activating (by phosphorylation) rather than inactivating in phosphorylation cascades. Phosphatases are the enzymes that remove phosphate groups and can inactivate proteins in these cascades.

Answer:

cause a structural change in each phosphorylated protein.