Final answer:
GTP binding proteins play crucial roles in signal transduction and protein synthesis, acting as molecular switches to regulate cellular processes such as vision, taste, and immune response.
Step-by-step explanation:
GTP binding proteins serve critical roles in cellular function, particularly in signal transduction and protein synthesis. These proteins act as molecular switches that turn on or off signaling pathways when they bind GTP and hydrolyze it to GDP. For example, during the cell signaling process involving G-protein-linked receptors, GTP binding induces a shape change in the G-protein, which releases GDP and picks up GTP. This leads to the dissociation of the G-protein subunits and the activation of other proteins within the cell. Another example is the role of GTP in the GNAT superfamily proteins, where it is important for binding CoA-SH and tRNA.
Globular proteins, such as enzymes like trypsin, have compact, nearly spherical shapes and are often involved in cellular transport and metabolism. These proteins can also act as GTP binding proteins that trigger physiological processes, including those related to vision, taste, immune system regulation, and inflammation. The hydrolysis of GTP to GDP by these proteins ultimately terminates the signaling response, ensuring proper regulation of cellular activity.