Question

Explain how cell signaling pathways in prokaryotes and eukaryotes demonstrate conservation of major features over time

Answer 1

Eukaryotic cells and prokaryotic cells are distant living things as they have differences even on the cellular level (i.e. the presence of a nuclear membrane, rRNA differences). Although even with these differences, the molecular biology especially for cellular metabolism and signaling pathways are conserved. One of the more common signaling pathway that is seen in both prokaryotes and eukaryotes is the G-protein pathway which involves a seven pass or serpentine protein with an intrinsic GTPase activity (hence the name) which then signal either the production of cAMP or IP3/DAG wherein these second messengers will activate certain protein kinases that will phosphorylate specific proteins and enzymes and regulate cells’ function.

Answer 2

Cellular structures and lifestyles are much diversified. In spite of these differences, the same basic molecular mechanisms govern the lives of both prokaryotes and eukaryotes, the general classes of proteins involved in signal transduction are conserved all over living cell. This is manifested through the re-used of protein receptors, protein kinases, phosphoprotein phosphates, and ion channel receptors.