AP BIOLOGY

Detailed explanation-1: -Receptors are generally transmembrane proteins, which bind to signaling molecules outside the cell and subsequently transmit the signal through a sequence of molecular switches to internal signaling pathways.

Detailed explanation-2: -In a gap junction, the lipid bilayer of adjacent cells is pierced through by proteins called connexons. These proteins group together and effectively form a group of communication tunnels between adjacent cells.

Detailed explanation-3: -Signals Pass From Protein to Protein Signals most often move through the cell by passing from protein to protein, each protein modifying the next in some way. Collectively, the proteins that relay a signal to its destination make up a signaling pathway. A signaling pathway can have few or many steps.

Detailed explanation-4: -Cells typically communicate using chemical signals. These chemical signals, which are proteins or other molecules produced by a sending cell, are often secreted from the cell and released into the extracellular space. There, they can float – like messages in a bottle – over to neighboring cells.

Detailed explanation-5: -Chemical signals between cells are called ligands. A ligand is a molecule that binds another specific molecule. In the case of cell signaling, the ligand binds a receptor, a protein in or on the target cell. Examples of ligands include hormones and neurotransmitters.