UPDATE 2026
Chloroplast - Answers Responsible for Photosynthesis
Green due to high chlorophyll, but can have other pigments
Thylakoid - Answers Where light rxn occurs
Light RXN - Answers Pigment captures ligth energy
H2O spilts and O2 evolved
High energy e- from H2O to O2 used to produce ATP and NADPH
Stroma - Answers Where Calvin Cycle occurs
Aqueous fluid surrounding thylakoid
Calvin Cycle - Answers CO2 is fixed using ATP and NADPH formed in light rxn
Principal Pigments - Answers Drive photosynthetic electron transport
Needed for photosythesis
Ex: Chlorophyll a, bacteriochlorophyll
Accessory Pigments - Answers Absorb photons and donate to principal
Protect organism from excess light
Xanthophylls - Answers Type of carotenoid pigments (accessory)
Protects from photoinhibition
Functions through xanthophyll cycle
Uses excess light energy to produce heat
Antenna complex/ light harvesting complex (LHC) - Answers Pigments molecules
cooperate to harvest light energy
Transfers light energy to RXN center complex
Size, # pigment molecules, type of pigment depend on light quality
RXN center complex - Answers Chlorophyll molecules that receive light from
antenna complex
Converts ligtht energy to chemical energy using oxidation-reduction rxns
Organization of light absorbing pigments in antenna complex - Answers Highest
excitation energy at top
Ensures efficient transer of light energy to rxn center complex
Some of energy transfered down released as heat, the rest of energy used in
photosynthetic rxns
Photosystem I (P700) - Answers Low energy (high redox potential)