photosynthesis Flashcards
Photosynthesis takes place…
inside a chloroplast in a plant cell
There are two stages of photosynthesis … where do each occur
the first are the light dependent reactions and the light interdependent reactions or the Calvin cycle. Light reactions occur in the thylakoid membrane and the Calvin cycle happens in the stroma.
what happens to water in the light reactions
In the light reactions water is split into two H+ ions two electrons and ½ 02 the oxygen gas formed in the light reactions is a waste product
draw and label a chloroplast
thylakoid membrane outer membrane inner membrane intermembrane space stroma thylakoid granum
what are the three fates when light meets matter
The electron returns to its ground state by emitting a less energetic photon (fluorescence) or by releasing energy as thermal energy
The electron returns to its ground state and the energy released is transferred to a different electron in a neighboring pigment molecule
The high energy electron is accepted by an electron accepting molecule the primary acceptor
The absorption spectrum…..
is a graph
the amount of light energy at various wavelengths that a substance can absorb (chlorophyll and carotenoids)
the action spectrum….
is a graphy of the effectiveness of light energy of different wavelengths in a driving chemical process (photosynthesis)
define a photosystem
a photosystem is a collection of pigment proteins that includes chlorophyll a and absorbs light at the 700nm wavelength (photosystem 1) or 680nm wavelength (photosystem II) mechanism in plants by which chlorophyll absorbs light energy for photosynthesis
where are photosystems located
the photosystems are located on the thylakoid membrane which is where the light reactions occur
what are photosystems made up of
photosystems are made of a protein complex called a reaction centreThese absorb light, promoting an electron to a higher energy level within the pigment. Which is surrounded by several light harvesting complexes. Each light harvesting complex has various pigment molecules (which may include chloraphyll a chloraphyll b and coratanoids) bound to protiens. The number and variety gives them greater surface area and portion of the spectrum
the difference between PSI and PSII
the difference between PSI and PSII is that PSI absorbs best at 700nm wavelengths and PSII absorbs best at 680nm wavelengths
Photolysis
Photolysis is the process by which water is split into oxygen, which is released into the atmosphere, and hydrogen. The hydrogen then becomes bonded to the coenzyme NADP to form NADPH and is transferred to the Calvin Cycle along with ATP.
what does CO2 bind to at the begining of the calvin cycle and what enzyme is needed
co2 binds to RuBP at the begining of the calvin cycle
and the enzyme needed is rubisco
the energy source for these reactions in the calvin cycle are….
ATP, and high-energy electrons and hydrogen ions from the NADPH
the products of each of reactions of the calvin cycle
from the carbon fixation every 3 molecules of Co2 that are produced, 3RuBP are carboxylated forming 6 molecules of 3-PG, from the reduction stage for every 3 Co2 that enter the calvin cycle 6 g3p are produced but the net gain is only one because the other five go to regenerate RuBP, lastly from the regeneration of RuBP it takes those same 5 g3p molecules which turns into 3RuBP molecules. For the formation of G3P the calvin cycle must turn three times to produce one and for the formation of glucose it takes two g3p to make so it takes six full turns
