Unit 3 Photosynthesis Flashcards
What part of the plant is responsible for the intake of solar energy?
Leaves (maximize surface area)
What part of the plant is responsible for the intake of water?
Roots (uptake) and stomata (transpiration)
What part of the plant is responsible for the intake of nutrients?
Roots (uptake via capillary action)
What part of the plant is responsible for the intake of CO2?
Stomata
Where do light reactions occur?
Light reactions occur in the thylakoid.
What do light reactions do?
Light reactions convert solar energy (photons) to chemical energy (ATP and NADPH).
What do light reactions lead to?
Light reactions lead to photophosphorylation.
What is photophosphorylation?
Photophosphorylation is the light-dependent formation of ATP by chemiosmosis in photosynthesis.
How many photosystems are present in light dependent reactions?
Two
Where are the photosystems located?
Photosystems are located in the thylakoid membranes.
What do the photosystems contain?
Photosystems contain pigments.
What is the purpose of accessory pigments?
Accessory pigments absorb and pas energy to chlorophyll a (the reaction site).
What happens when 2 electrons become excited in chlorophyll A?
The electrons are transferred to the Electron Transport Chain.
What do the electrons falling from PSII replace?
The electrons falling from PSII replace electrons lost to the ETC.
What does the Energy produced by the transfer of fallen PSII electrons to chlorophyll a produce?
The energy produced by the transfer reduces NADP+ to NADPH.
Which occurs first, PSI or PSII?
PSII occurs first.
What is the purpose of PSII?
PSII generates ATP via chemiosmosis as electrons pass down its transport chain.
What is the purpose of PSI?
PSI generates NADPH when electrons reach the end of its electron transport chain?
Photolysis of water occur?
Photolysis occurs when chlorophyll a (the reaction center) lacks an electron.
Which enzyme catalyzes the splitting of water in photolysis?
Enzyme Z catalyzes the splitting of water into photolysis.
What does water split into?
Water becomes O, H ions, and a pair of electrons for replacement of the ones missing from chlorophyll a.
How is O released?
O is released as O2.
What are the four steps of cyclic photophosphorylation?
- PSI electrons go to the first electron carrier.
- The electrons pass to the PSII chain.
- Their energy is used to generate ATP.
- The electrons are returned to PSI.
What is the equation of photosynthesis?
6CO2 + 6H2O + Light energy → C6H12O6 + 6O2
How does water move out of the plant?
Transpiration: the loss of water vapour from plant tissues, primarily through stomata.
What does evaporation of water create?
Evaporation of water from leaves creates a transpirational pull which helps move water, minerals and other substances from the roots to the leaves and other parts of the plant. Also provides cooling effect.
What happens in terms of CO2 and O2 movement, and the rate of photosynthesis when the stomata are open?
CO2 can diffuse into the leaf quickly (less CO2 in plant because it is used up in photosynthesis. O2 can diffuse quickly out of the leaf (more in the plant because it is a product of photosynthesis).
The rate of photosynthesis is high.
What controls stomatal action?
The concentration gradient created by the active pumping of K+ ions into the guard cells controls stomatal action.
What happens when water diffuses into the guard cells?
When water diffuses in, the turgor pressure increases and the guard cells swell and subsequently buckle, opening the stomata.