Photosynthesis Flashcards
(12 cards)
Photosynthesis
- carried out by different organisms, and occurs in the chloroplasts of plants and some protists
- involves using energy from sunlight to form carbohydrates through many enzyme catalyzed reactions
Chloroplasts
membrane bound organelles in plant and algal cells that carry out photosynthesis
Chlorophyll
absorbs light energy and begins the process of photosynthesis
Thylakoid
a system of interconnected flattened membrane sacs forming a separate compartment within the stroma of a chlorplast
Grana
a stack of thylakoids
Light Reactions (light dependent)
- photoexcitation; absorption of a photon by an electron of chlorophyll
- ETC; transfer of excited electrons to create NADPH and a concentration gradient of H+ (occurs in thylakoid membrane)
- chemiosmosis; movement of protons (H+) through ATP synthase to create ATP
C4 Plants
plants that live in hot tropical climates where photorespiration would otherwise convert more than half of the glucose back to CO2 (e.g sugar cane and corn)
CAM Plants
plants that live in hot/dry conditions (desert) where there is the need to conserve water (e.g cacti and pineapples)
Calvin Cycle
series of reactions that convert carbon dioxide into carbohydrates (occurs in the stoma of chloroplasts)
- Carbon Fixation
- Reduction
- Regeneration
Non-Cyclic and Cyclic Electron Flow
- in noncyclic electron flow, electron are transferred to photosystem I and then ultimately transfered to NADP+ to produce NADPH (therefore the electrons are lost, only being replaced by the splitting of water)
- in cyclic electron flow, electrons from photosystem I are transferred back P700, the photochemical reaction center of photosystem I, supplying more ATP but no NADPH
Photorespiration
oxidation of RuBP by rubisco and oxygen in light to form glycolate, which subsequently releases carbon dioxide
Dark Reaction (light independent)
Calvin Cycle
