Chapter 11 introduce to cell communication. This chapter presents the following content: External signals are converted to responses within the cell; reception: a signal molecule binds to a receptor protein, causing it to change shape; transduction: cascades of molecular interactions relay signals from receptors to target molecules in the cell;. | Chapter 11 Cell Communication Overview: The Cellular Internet Cell-to-cell communication Is absolutely essential for multicellular organisms Biologists Have discovered some universal mechanisms of cellular regulation Figure Concept : External signals are converted into responses within the cell Evolution of Cell Signaling Yeast cells Identify their mates by cell signaling factor Receptor Exchange of mating factors. Each cell type secretes a mating factor that binds to receptors on the other cell type. 1 Mating. Binding of the factors to receptors induces changes in the cells that lead to their fusion. New a/ cell. The nucleus of the fused cell includes all the genes from the a and a cells. 2 3 factor Yeast cell, mating type a Yeast cell, mating type a/ a a Figure Signal transduction pathways Convert signals on a cell’s surface into cellular responses Are similar in microbes and mammals, suggesting an early origin Local and Long-Distance Signaling Cells in a multicellular organism Communicate via chemical messengers Animal and plant cells Have cell junctions that directly connect the cytoplasm of adjacent cells Plasma membranes Plasmodesmata between plant cells Gap junctions between animal cells Figure (a) Cell junctions. Both animals and plants have cell junctions that allow molecules to pass readily between adjacent cells without crossing plasma membranes. Figure (b) Cell-cell recognition. Two cells in an animal may communicate by interaction between molecules protruding from their surfaces. In local signaling, animal cells May communicate via direct contact In other cases, animal cells Communicate using local regulators (a) Paracrine signaling. A secreting cell acts on nearby target cells by discharging molecules of a local regulator (a growth factor, for example) into the extracellular fluid. (b) Synaptic signaling. A nerve cell releases neurotransmitter molecules into a synapse, stimulating the . | Chapter 11 Cell Communication Overview: The Cellular Internet Cell-to-cell communication Is absolutely essential for multicellular organisms Biologists Have discovered some universal mechanisms of cellular regulation Figure Concept : External signals are converted into responses within the cell Evolution of Cell Signaling Yeast cells Identify their mates by cell signaling factor Receptor Exchange of mating factors. Each cell type secretes a mating factor that binds to receptors on the other cell type. 1 Mating. Binding of the factors to receptors induces changes in the cells that lead to their fusion. New a/ cell. The nucleus of the fused cell includes all the genes from the a and a cells. 2 3 factor Yeast cell, mating type a Yeast cell, mating type a/ a a Figure Signal transduction pathways Convert signals on a cell’s surface into cellular responses Are similar in microbes and mammals, suggesting an early origin Local and Long-Distance .
