Final answer:
Intracellular signaling proteins, through processes such as phosphorylation, are responsible for modifying target proteins, triggering the appropriate cellular responses that follow the reception of a signal by cell surface receptors.
Step-by-step explanation:
Intracellular signaling proteins are responsible for the modification of target proteins, resulting in a cellular response.
In the process of signal transduction, a signal received by a receptor on the surface of a cell triggers a cascade of events involving various intracellular signaling proteins. These proteins often change the function of target proteins through the process of phosphorylation, which alters their shape and activity. Enzymatic modifications, like those carried out by kinases, lead to a broad range of cellular responses. These responses include changes in gene expression, metabolism adjustments, growth regulation, and even programmed cell death or apoptosis.
The regulation of these pathways is crucial to ensure proper activation and termination of cellular responses, thus maintaining cellular health and function. Phosphatases can deactivate pathways by removing phosphate groups, highlighting the dynamic nature of these signaling processes.