Ib bio 2.9 Flashcards
what colour of light does chlorophyll absorb and reflect?
-absorbas red and blue
-reflects green
What are the functions of O2 in photosynthesis?
-photolosysis in photsystem 11 for electron
Effects of photosynthesis on the earth?
-changes to the earths atmosphere, oceans, and rock disposition
-rise in the O2 conc in atmosphere(release in photosynthesis)
-great oxidation event
-glaciation due to greenhouse effect
-decrease of CO2. Conc
-oxidation from O2 conc in oceans cuased dissolved iron in water to fall onto the sea bed rock formation was produced
Limiting factors
- temp
-co2 conc
-light intensity
What will low light limit in photosynthesis?
-ATP and NADPH
-in Calvin cycle when we need ATP + NADPH to convert glycerin-3-phosphate into triose phosphate
What will the CO2 conc limit in photosynthesis?
-Carbon fixation will be limited cuz g3p will be limited production
-as a result have atp and NADPH accumulating
What will the temp limit in photosynethsis?
-Calvin cycle
- when carbon being fixed (when rubisco use)
-low= reactions wont happen enough
-high= denature the enzyme
What is the diff between light dependent and independent reactions?
-takes place in intermebnrane of thylakoid in stoma
-Ind: takes place in dark for phew seconds cuz has energy from photosystems
-dep: generate ATP and NADPH for ind reaction
Blue light nanometers
450-500
Green nanomètres
525-575
Red nanometers
650-700
Do shorter wavelengths contain more or less energy?
Higher energy
Longer wavelengths contain… energy
Lower energy
Absorption vs action spectra
Absorption: shows % of light absorbed at each wavelength by pigment
Action: graphs shows rate of photosynthesis at each wavelength of light
Is the production of carbs exo or en do
Exothermic
Photon gradient
-PS11
-as electron pass in ETC, energy is released and used to pump protons across thylakoid membrane into space and inside thylakoid
What does CEPS stand for in a basic leaf structure
C-cuticle
E-epidermis
P-palisade mesophyll
S-spongy mesophyll
What do the “viens” or vesicular tissue contain in a plant?
-phloem
-xylem
Explain the process of transpiration
-where water travels from root to leaves and excites through stomata as water vapour
-xylem carries water to various parts of plant, which is needed for photosynthesis
-carries other small minerals along w water
-water lost on leaves through evaporation that needs to be replaced by roots
How much h20 taken in by roots is lost as transpiration?
90%
What is a function that transpiration helps the plant?
-cooling down the plant when h20 evaporates from stomata (just like sweating)
Where does the water in transpiration evaporate from?
The stomata
What does the loss of water in transpiration result in?
-negative pressure and a pull on water from xylem
What are the H+ ions used for in photosystems?
-to be a co-transporter for sucrose to move across cell
-for the NADPH (reduced NADP)
In plants are there a higher conc of H+ ions in or out of the cell? Why?
-outside the cell
-accumulate from splitting of water (photolysis), originally for electron replacement (non-cyclic phototphosporalytion)
