AP BIOLOGY

Detailed explanation-1: -The ligand crosses the plasma membrane and binds to the receptor in the cytoplasm.

Detailed explanation-2: -Paracrine signaling Often, cells that are near one another communicate through the release of chemical messengers (ligands that can diffuse through the space between the cells). This type of signaling, in which cells communicate over relatively short distances, is known as paracrine signaling.

Detailed explanation-3: -Signaling molecules bind to the extracellular domain of two nearby tyrosine kinase receptors, which then dimerize. Phosphates are then added to tyrosine residues on the intracellular domain of the receptors and can then transmit the signal to the next messenger within the cytoplasm.

Detailed explanation-4: -The steroid hormones diffuse across the plasma membrane and bind to nuclear receptors, which directly stimulate transcription of their target genes.

Detailed explanation-5: -Hydrophobic signaling molecules ( ligands ) can diffuse through the plasma membrane and bind to internal receptors.