AP BIOLOGY

Detailed explanation-1: -Transduction: When the signaling molecule binds the receptor it changes the receptor protein in some way. This change initiates the process of transduction. Signal transduction is usually a pathway of several steps. Each relay molecule in the signal transduction pathway changes the next molecule in the pathway.

Detailed explanation-2: -Signal transduction (also known as cell signaling) is the transmission of molecular signals from a cell’s exterior to its interior. Signals received by cells must be transmitted effectively into the cell to ensure an appropriate response. This step is initiated by cell-surface receptors.

Detailed explanation-3: -The most common signal transduction process is protein phosphorylation, where proteins are catalyzed by enzymes known as protein kinases. Signal transduction results in a desired cellular response. This can depend on the type of cell itself. Major pathways include the MAPK/ERK pathway and the cAMP-dependent pathway.

Detailed explanation-4: -Signal transduction pathway involves the binding of extracellular signaling molecules and ligands to receptors located on the cell surface or inside the cell that trigger events inside the cell, to invoke a response. The response can then alter the cell’s metabolism, shape, and gene expression (Krauss, 2006).

Detailed explanation-5: -As already noted, all signaling molecules act by binding to receptors expressed by their target cells. In many cases, these receptors are expressed on the target cell surface, but some receptors are intracellular proteins located in the cytosol or the nucleus.