Photosynthesis Flashcards
what are photons
wave packets of electromagnetic radiation
what are the two steps of photosynthesis
light dependent and light independent reactions
where does light dependent reactions occur
thylakoid membrane
where does light independent reactions occur?
stroma
what are the three stages of light reactions
photo excitation
electron transport
chemiosmosis
what is photo excitiation
the first stage of light reactions
one of the chlorophyll’s electrons gets excited by a photon
what is electron tranpsort
the second stage of light reaction
along a series of carriers creating a hydrogen ion resevoir
what is chemiosmosis
protons move throughout ATP synthase to make ATP
where is starch stored
in roots and chloroplasts
what is photorespiration
the reaction of oxygen with rubisco in a process that reverses carbon fixation and reduces the efficiency of photosynthesis
(O2 takes the place of CO2, so that the calvin cycle cannot occur)
where does the calvin cycle occur
in the stroma
how is glucose formed through the calvin cycle
2G3P merge to form 1 glucose molecule
explain the steps in photoexcitation
- photon is absorbed into photosystem II
- it bounces around from pigment to pigment until it reaches chlorophyll a molecule
- an electron from the chlorophyll a gets excited and goes to the primary electron acceptor
- it pulls apart H2O to take the electron back, releasing O2
explain the steps of electron transport
- after the electrons are pulled apart, they get moved to the electron acceptor
- then transported to the electron carrier protein which brings it to B6-F complex
- the B6-F complex pushes out the H+ to form an electron gradient which is needed for chemiosmosis
- meanwhile the same stuff occurs in photosystem I except the electrons needed to balance the chlorophyll a comes from the electron carrier
- the NADP reductase norms NADPH
explain the steps of chemiosmosis
the electron gradient formed by the b6-f complex aids in the function of the ATP synthase, which pumps H+ through, turning ADP into ATP
what is different about C4 plants
they have seperate areas where O2 and CO2 reside
where do C4 plants typically grow
tropical areas where it’s always hot
what are the two cells in C4 plants and their order
mesophyll cell – where co2 enters and is converted to malate
bundle-sheath cell – where calvin cycle occurs
explain the difference process in C4 plants
- CO2 reacts with pop to form oxaloacetate
- oxaloacetate to malate (NADPH to NADP+)
- malate to CO2 and pyruvate
- pyrivate to pep (ATP to AMP)
where do CAM plants grow
tropical areas
hot days, cold nights
explain how CAM plants work
- they take in he CO2 overnight, when it’s not dangerous to have open stomata (lower risk of losing water)
- converts it to oxaloacetate and then malate to be stored
- in the day, when the sun is shining, the malate is converted back to CO2 to do the krebs cycle
what are autotrophs
self feeders
they sustain themselves without eating anything derived from other living beings
what are photoautotrophs
a type of autotrophs that use light for energy
what are heterotrophs
unable to make their own food; they live on compounds produced by other organisms
