BSC 196 Lecture Notes - Lecture 29: Morphine, Coleoptile, Auxin
Document Summary
There are multiple ways in which a stationary plant with no nerves or muscles assesses and responds to its surroundings. Internal and external signals are detected by receptors, proteins that change in response to specific stimuli. Second messengers transfer and amplify signals from receptors to proteins that cause responses: response. A signal transduction pathway leads to regulation of one or more cellular activities. In most cases, these responses to stimulation involve increased activity of enzymes. Transcriptional regulation to increase or decrease the production of an enzyme. Specific transcription factors bind directly to specific regions of dna and control transcription of genes. The second messengers such as cgmp and ca2+ activate protein kinases directly: protein phosphatases (cid:862)switch off(cid:863) the signal transduction pathways by dephosphorylating proteins. Exposure to light: de-etiolation - shoots and roots grow normally. Plant hormones are chemical signals that modify or control one or more specific physiological processes within a plant.
