BIOL 1050 Lecture Notes - Lecture 20: Nitrate, Electrochemical Gradient, Solar Tracker

• School: University of Guelph
• Department: Biology
• Course: BIOL 1050
• Professor: Steve Bowley

Document Summary

Action spectrum in uv-a and blue region. Shoulder at 425, major peak 450, minor peak 470 nm. Blue light is used for: cryptochromes. Animals also use this light thing: phototropins. Alter growth in response to light (grow towards light: zeaxanthin (a xanthophyll) A blue response limited to guard cells. O(cid:373)e pla(cid:374)ts (cid:272)a(cid:374) (cid:272)o(cid:374)ti(cid:374)uousl(cid:455) adjust lea(cid:448)es to (cid:271)e pe(cid:396)pe(cid:374)di(cid:272)ula(cid:396) to su(cid:374)"s (cid:396)a(cid:455) (cid:894)+/- 15degrees) Increase photosynthesis in early and late periods of the day: reorients before, dawn. Examples of plants that do this: alfalfa and other legumes: sensor inpulvinus (petiole-blade junction, sunflower younger parts of stem. O(cid:455)(cid:271)ea(cid:374), su(cid:374)flo(cid:449)e(cid:396)s, la(cid:373)(cid:271)"s (cid:395)ua(cid:396)te(cid:396)s pla(cid:374)ted so (cid:396)o(cid:449)s (cid:449)e(cid:396)e pe(cid:396)fe(cid:272)tl(cid:455) o(cid:396)ie(cid:374)ted east-west. Sun rises in east, sets in west. As the day prog(cid:396)esses a(cid:374)d the su(cid:374) (cid:373)o(cid:448)es, the pla(cid:374)t"s lea(cid:448)es (cid:373)o(cid:448)e to follo(cid:449) the su(cid:374) Many processes oscillate through the day: legumes close/lower their leaflets at night, plant gene expression. Some genes increase during night, some are repressed during night. 30% have circadian rhythms: circadian rhythm.