Concepedia

Abstract

Cells adjust their behavior continuously in response to changing environmental conditions. Stimuli include a wide range of chemicals, such as amino acids, peptides, sugars, oxygen, phosphate, ammonia, pheromones, hormones, and neurotransmitters, as well as parameters such as electrochemical potential, temperature, pressure, and light. Responses include regulation of gene expression, changes in metabolism, altered membrane permeability, and cell motility. One of the major unsolved problems in molecular biology is to understand how information from such a large number of sensory inputs is used to formulate an appropriate array of response strategies.