Chapter 21
Principles of Cell Signaling

Despite the protective membrane that separates a cell from the environment, cells need the ability to detect and respond to environmental changes.…

In multicellular organisms, many molecules transmit signals between cells to pass information. These signals vary in complexity and include small…

Many cellular signals are hydrophilic and cannot pass through the plasma membrane. However, small or hydrophobic signaling molecules can cross the…

Multiprotein signaling complexes are formed in a dynamic process involving protein-protein interactions at the cytoplasmic domain of transmembrane…

Many receptor binding ligands are hydrophilic; they do not cross the cell membrane but bind to cell-surface receptors. Thus, their message must be…

When a ligand binds to a cell-surface receptor, the receptor's intracellular domain changes shape, which may either activate its enzyme function…

Positive and negative feedback loops are crucial for regulating biological signaling systems. These feedback loops are processes that connect output…

Plant cells communicate to coordinate their cycle of growth, flowering and fruiting, and activities in roots, shoots, and leaves in response to the…

Aberrant cell signaling plays a central role in cancer development and progression. Most novel targeted therapies are indeed directed at proteins and…

Plants respond to mechanical stresses such as wounding and herbivory by inducing defense responses both in the damaged and in the distal undamaged…