AP Biology Chapter 10 Quiz Flashcards
Photosynthesis Equation
6CO2 + 6H2O + Energy -> C6H12O6 + 6O2
Stages of Photosynthesis and Location
- Light Reactions (Dependent): Thylakoid membrane of chloroplasts
- Convert solar energy to the chemical energy of ATP and NADPH
- O2 is released
- Calvin Cycle “Dark Reactions”: Stroma of chloroplasts
- Involves atmospheric CO2 fixation and reduction of carbon into carbohydrate
- Glucose molecule is released
Roles of Pigments
- Substance that absorbs and reflects light
- Chlorophyll: Green
- Chlorophyll a: Blue green
- Chlorophyll b: Yellow-green
- Carotenoids: Red-orange
- Absorption at the higher points of the line
- Reflection at the lower points of the line
ATP Cycle
ATP —-> Exergonic (Energy for cellular work) —-> ADP + Pi (+ heat) —-> Endergonic (Energy from cellular respiration)
Thylakoid Structure
- Thylakoid: Disk-shaped sacs in the stroma of a chloroplast
- Thylakoid Membrane: Photosynthetic membrane within a chloroplast that contains light gathering pigment molecules and electron transport chains
- Thylakoid Space: A fluid-filled interior space enclosed by the thylakoid membrane
- Granum: Stack of thylakoids; increase surface area to volume ratio
Light Reactions: Electron donor and final destination
- Electron Donor: Water in photosystem II
- Splits into O2, protons, and electrons
- Electrons are supplied to the P680
- Oxidation of water
- Final Destination: NADPH
- Electrons end up being captured by the electron carrier NADPH
Purpose of Cyclic Electron Flow
- More ATP can be made without NADH
- Calvin Cycle consumes more ATP than NADH
- Cyclic flow occurs if ATP is low
- Electrons are reused rather than flowing from one component of the light reaction to another
- Goes back to photosystem I
Light Reaction Diagram
Light —-> Photosystem II (light strikes pigment molecule until it reaches the reaction center) —-> Plastoquinone —->Cytochrome C —-> Plastocyanin —-> Photosystem I (with light) —-> Ferrodoxin —-> NADP+ reductase —-> NADPH H+
- Undergoes oxidation reduction
NADP+/NADPH
- Electron acceptor that temporarily stores energized electrons produced during light reactions
- A compound that donates one hydrogen aton and two electrons to another molecule, to reform NADP+; it is an electron donor
G3P
- Phase 2: Reduction in the Calvin Cycle forms the glucose molecule
- Final glucose produced in photosynthesis
- Three carbon sugar
RuBP
- Phase 3: Regeneration of the CO2 Acceptor in the Calvin Cycle
- Regenerates RuBP with some help from ATP
Rubisco
Enzyme that catalyzes the first step of the Calvin Cycle
CAM Adaptation
- Adaption of photosynthesis in arid conditions
- Dehydrated plants in the desert
- Stomata (pores in the plants) let out water
- Want the stomata closed during the day because you do not water the water to vaporize
- Photosynthesis only occurs in the daytime
- But you need CO2
- Subset of C4 plants
- Keep their stomata open during the night letting in CO2
- Produces malate which is stored in other organelles (CO2 storage)
- CO2 is released from the malate and enters the Calvin Cycle