Chapter 10 Flashcards
Photosynthesis
Conversion of light energy to chemical energy stored in organic compounds
Autotrophs
Organisms that get food without eating other organisms
What type of autotrophs are plants
Photoautotroph
Heterotrophs
Organism that is fueled by eating other organisms
Mesophyll cells
Leaf cells specialized for photosynthesis
What cells are chloroplast found
Mesophyll cells
Stomata
Microscopic pore surrounded by guard cells which allow for gas exchange
Chlorophyll
Green pigment found in thylakoid membrane of chloroplast
Formula for photosynthesis
6(CO2)+6(H2O)+light➡️ C6H12O6+6O2
What is reduced in photosynthesis
Carbon dioxide which is reduced to glucose
What is oxidized in photosynthesis
H2O which is oxidized to Oxygen
How is carbon dioxide reduced in photosynthesis
Electrons from water is transferred to it
Light reactions
Converts solar energy to chemical energy releasing oxygen
Calvin cycle
Fixation of atmospheric CO2 and reducing it to carbohydrate
NADP
NAD with phosphate group attached to it
NADP+
Oxidized form of NADP which accepts electrons
NADPH
reduced form of NADP which stores and donates energized electrons
Photophosphorylation
Process of making ATP using chemiosmosis across thylakoid membrane in light reactions
Carbon fixation
Initial incorporation of carbon from CO2 into organic molecules by autotrophic organisms
Wavelength
Distance between crest of waves
Photons
quantity of light energy that behaves as if it were a particle
Pigments
Substances that absorb light
What colors are absorbed by chlorophyll
Violet-blue & red light
Absorption spectrum
Range of pigments ability to absorb various wavelengths of light
Chlorophyll a
Main pigment in chlorophyll which is directly involved in light reactions
The 2 Accessory pigments
Chlorophyll b & carotenoids
Photosystem
Light capturing unit in membrane consisting of a reaction-center complex surrounded by light harvesting units
Reaction center complex
Complex of proteins with a pair of chlorophyll a molecule & primary electron acceptor
Light harvesting complex
Complex of proteins associated with pigment molecules that capture light & transfer it to reaction center pigments in photosystems
Function of primary electron acceptors in photosystems
Capture excited electrons of chlorophyll a
Photosystem 2
Has 2 molecules of P680 chlorophyll at reaction center
Photosystem 1
Contains 2 molecules of p700 chlorophyll a at its reaction center
Linear electron flow
Route of electrons flow during light reactions that involves both photosystems
What are the products in linear electron
ATP,NADH, & oxygen
Cyclic energy flow
Route of electrons in light reactions which involve only one photosystem; only produces ATP
Where does cyclic energy flow occur
Photosystem 1
Direction of H+ during chemiosmosis in chloroplast
H+ diffuse from thylakoid space to stroma through ATP synthase
How many molecules of CO2 is used to produce 1 G3P
3 CO2
Rubisco (ribulose bisphosphate carboxylase-oxygenase)
The enzyme that catalyzes CO2 and RuBP reaction
How much NADPH and ATP is used in the calvin cycle
9 ATP and 6 NADH
What causes O2 to build up in C3 plants
In hot temperatures stomata closes to conserve water. This builds up O2 but loses CO2
C3 plants
Plant that uses the initial steps of rubisco adding CO2 to ruBP in the calvin cycle
Photorespiration
Metabolic pathway that uses O2 & ATP, releasing CO2 reducing photosynthetic output
When does photorespiration most likely occur
Hot days
C4 plants
Plants that form 4-carbon compound as its first molecule
Bundle sheath cells
Cells arranged into tightly packed sheath ls around the veins of a leaf
PEP carboxylase features
Higher affinity for CO2 than rubisco and no affinity for O2
PEP carboxylase
Enzyme that adds CO2 to PEP to make oxalacetate in mesophyll cells of C4 plants
Crassulacean acid metabolism
Plants fix CO2 into variety of organic acid at night and release organic molecules at day
