BIOLOGY 172 Chapter Notes - Chapter 9.1-9.3: Autocrine Signalling, Cytosol, Action Potential
Document Summary
Activities of virtually all cells are influenced by their surroundings. Sources of information: physical environment, neighboring cells, nearby cells, distant cells. Cells communicate using chemical signals that bind to specific receptors. Signaling cells are the source of the signaling molecules. Signaling molecules vary immensely and include peptides, lipids, and gases; carry info from one cell to the next; binds to a receptor protein on or in responding cell. By taking up dna from environment, bacterial cells can acquire genes with advantageous properties such as antibiotic resistance. Quorum sensing is a process by which bacteria are able to determine where they are at high or low population density and then turn on specific genes. Signaling involves receptor activation, signal transduction, responses, and termination. Receptor activation is the turning on of a receptor, which often occurs when a signaling molecule binds to a receptor on a responding cell: usually activates receptor by causing conformational changes.
