Final answer:
Signal transduction metabolites like cyclic-AMP are important for signal amplification within cells, and for activating kinase cascades that modify target proteins to elicit cellular responses.
Step-by-step explanation:
Two fundamental properties of signal transduction metabolites, such as cyclic-AMP or fructose-2,6-bisphosphate, are:
- Signal Amplification - These molecules serve to amplify the signal received by the cell. For example, cyclic-AMP is created from ATP by the enzyme adenylyl cyclase in response to hormonal signals. A single hormone-receptor interaction can lead to the synthesis of many cyclic-AMP molecules, thus amplifying the original signal.
- Activation of Kinases - Metabolites such as cyclic-AMP activate a cascade of protein kinases. Specifically, cyclic-AMP activates the cAMP-dependent protein kinase (PKA), which then phosphorylates serine and threonine residues on target proteins, modulating their activity.
These properties are crucial for cells to convert extracellular signals into appropriate cellular responses.