2.3

autotrophs

• “self feeders”

• producers- generate food from non living sources (like CO2)

photoautotrophs

use light energy to synthesize organic compounds

heterotrophs

• “other feeders”

• consumers- live on compounds produced by other organisms

types of photosynthetic autotrophs

plants (land; forest plants)

photosynthetic protists (aquatic; kelp)

photosynthetic bacteria (aquatic; cyanobacteria)

photosynthesis

• captures light energy, stores in stable forms (light → carbohydrates)

• smaller molecules are combined using energy from light

cellular respiration

• converts energy from stable to versatile forms (carbohydrates → ATP)

• breaking down larger molecules releases energy captured as ATP

endosymbiosis

one organism living inside another

eukaryotic ancestor engulfed prokaryotes

O2 using → mitochondrion

photosynthetic → chloroplast

evidence of endosymbiosis

• double membrane

• own DNA, ribosomes and proteins (prokaryote-like)

• autonomous growth/replication, energy production

photosynthesis ___ energy, respiration ___ energy

requires, releases

photosynthesis chemical equation

6CO2 + 12H2O + Light → C6H12O6 + 6O2 +6H2O

cellular respiration

[CH2O]n + O2 +ADP + P → CO2 + H2O + ATP

chloroplast- 3 membrane bound

(sites of photosynthesis)

• inter-membrane

• stroma

• thylakoid space

photosynthesis light reaction

“photo”

where: thylakoid

what: convert solar to chemical energy

calvin cycle dark photosynthesis recation

“synthesis”

where: stroma

what: transform chemical energy into storable forms

one goal of light reactions

transferring electrons from water to NADPH