Chapter 6
Cell Signaling
Despite the protective membrane that separates a cell from the environment, cells need the ability to detect and respond to environmental changes.…
Bacterial signaling can occur within bacteria (intracellular) or between bacteria (intercellular). At times, a group of bacteria behaves like a…
Yeasts are single-celled organisms, but unlike bacteria, they are eukaryotes (cells with a nucleus). Cell signaling in yeast is similar to signaling…
Contact-dependent signaling, as the name suggests, requires that communicating cells be in direct contact with each other. This is achieved either…
Autocrine signaling is one of the many signaling mechanisms that function inside multicellular organisms to carry out intercellular communication. In…
Paracrine signaling allows cells to communicate with their immediate neighbors via secretion of signaling molecules. Such a signal can only trigger a…
Neurons communicate at synapses, or junctions, to excite or inhibit the activity of other neurons or target cells, such as muscles. Synapses may be…
G-protein coupled receptors are ligand binding receptors that indirectly affect changes in the cell. The actual receptor is a single polypeptide that…
Many cellular signals are hydrophilic and therefore cannot pass through the plasma membrane. However, small or hydrophobic signaling molecules can…
Endocrine cells produce hormones to communicate with remote target cells found in other organs. The hormone reaches these distant areas using the…
Because many receptor binding ligands are hydrophilic, they do not cross the cell membrane and thus their message must be relayed to a second…
Once a ligand binds to a receptor, the signal is transmitted through the membrane and into the cytoplasm. The continuation of a signal in this manner…
The movement of ions like sodium, potassium, and calcium into and out of the cell is essential to maintain the electrochemical gradient in living…
Enzyme-linked receptors are proteins that act as both receptor and enzyme, activating multiple intracellular signals. This is a large group of…
Pharmacological regulation of Toll-like receptor (TLR) responses holds great promise in the treatment of many inflammatory diseases. However, there…
Protection against infectious diseases is mediated by the immune system 1,2. T lymphocytes are the master coordinators of the immune system,…
Cells dying by apoptosis, also referred to as regulated cell death, acquire multiple new activities that enable them to influence the function of…
