Biology 2483A Lecture Notes - Lecture 4: Vascular Bundle, C4 Carbon Fixation, Photorespiration

• School: Western University
• Department: Biology
• Course: Biology 2483A
• Professor: Graeme Taylorand Sheila Macfie

Document Summary

Lecture 4 coping with environmental variation, part ii: energy. Key concept # 1: organisms obtain energy from sunlight, inorganic compounds and through consumption of organic compounds: trade-off: if organisms don"t have the resources they won"t reproduce [until they have energy, maintenance and growth] Lettuce sea slug: autotrophic: light energy penetrates body to chloroplast, most sea slugs are not autotrophic. Heterotrophs: herbivores, predators, omnivores, detritivores detritus = dead organisms, parasites i. ) ii. ) iii. ) Hemi-parasitic plants: obtain water and nutrients from a host plant but can also photosynthesize i. e. mistletoe. Lichen: symbiosis between green algae or cynanobacteria (autotrophs) and a fungus (heterotroph) Key concept # 2: radiant and chemical energy captured by autotrophs is converted into stored energy in c-c bonds. Photosynthesis: solar radiation + water (e-) atp & nadph + co2 = organic molecules. 3 because 1 carbon becomes a 3 carbon molecule.