Guanosine triphosphate (GTP) is a nucleotide that plays a crucial role in cellular processes. It consists of a guanine base, a ribose sugar, and three phosphate groups. GTP is essential for protein synthesis and acts as an energy source, similar to adenosine triphosphate (ATP). In addition to its role in energy transfer, GTP is involved in signaling pathways within cells. It serves as a substrate for the synthesis of RNA during transcription and is also important in the function of G-proteins, which help transmit signals from outside the cell to its interior.