What is the actual "signal" being transduced in a signal transduction pathway? How is this "signal"passed from outside to inside the cell? - Questions? -> Textbook chapters/pages to review

Question 2: What is the actual "signal" being transduced in a signal transduction pathway?Answer: In a signal transduction pathway, the "signal" being transduced is typically a chemical signal, such as a hormone or neurotransmitter. This signal is received by a receptor protein on the cell surface or inside the cell, which triggers a series of biochemical reactions within the cell.Explanation: Signal transduction is the process by which a chemical or physical signal is transmitted through a cell as a series of molecular events, most commonly protein phosphorylation catalyzed by protein kinases, ending with a cellular response. Proteins responsible for detecting stimuli are generally termed receptors, although in some cases the term sensor is used. The changes elicited by ligand binding (or signal sensing) in a receptor give rise to a signaling cascade, which is a chain of biochemical events along a signaling pathway.Question 3: How is this "signal" passed from outside to inside the cell?Answer: The signal is passed from outside to inside the cell through a process called signal transduction. The signal, such as a hormone or neurotransmitter, binds to a specific receptor on the cell surface. This binding triggers a change in the shape of the receptor, which allows it to activate other proteins inside the cell. These proteins then trigger a series of reactions that lead to the desired response within the cell.Explanation: Signal transduction pathways are major mechanisms by which cells receive and respond to external stimuli. Each signal transduction pathway operates as a relay system: an extracellular signaling molecule (the signal) binds to a receptor embedded in the cell membrane, which triggers a chain of events inside the cell, leading to a response. The response could be almost anything: a change in the cell's metabolism, shape, gene expression, or ability to divide. Many drugs and poisons exert their effects by altering signal transduction pathways.Highlighted Answers:- The actual "signal" being transduced in a signal transduction pathway is typically a chemical signal, such as a hormone or neurotransmitter.- The signal is passed from outside to inside the cell through a process called signal transduction. The signal binds to a specific receptor on the cell surface, triggering a change in the shape of the receptor, which allows it to activate other proteins inside the cell. These proteins then trigger a series of reactions that lead to the desired response within the cell.