Chapter 10 - Photosynthesis Flashcards
Define photosynthesis
Capturing energy stored in light and converting it into chemical energy in glucose
Auto troughs versus heterotrophs
Autotroph’s produce organic molecules from an organic raw materials and CO2, heterotrophs nutrition
Producers, consumers, and decomposers
What organisms are photoautotrophs
Plants, algae, non-algal unicellular eukaryotes, cyanobacteria prokaryotes, other prokaryotes
Endo symbiotic theory: how did chloroplasts evolve
The outer membrane of an organism were enfolded and eventually created independent organelles, bacteria
Parts of the plant: mesophyll stomata stroma thylakoid chlorophyl
- tissue in interior of leaf
- microscopic pores on leaf, carbon dioxide enters and oxygen exits
- dense fluid, cytoplasm of the chloroplast
- third membrane, socks, stacked in grannum occasionally
The product of oxygen in photosynthesis comes from which reactant? Which reactant is reduced and which is oxidized? Where does each element of the reactance go of the products?
Comes from splitting of water, carbon dioxide is reduced, water is oxidized
Carbon to glucose, oxygen of carbon dioxide to glucose and water, hydrogen to water and glucose, oxygen and water to oxygen waste.
Photosynthesis is separated into which two processes
Light reactions and Calvin cycle
Light reactions capture light energy, Calvin cycle synthesizes organic molecules
What is photophosphorylation
Chemiosmosis powered by light reactions of ADP to make ATP
What is carbon fixation
Incorporating carbon into organic compounds
What powers the energy needed in Calvin cycle
NADPH from the light reactions and ATP from light reactions
Where do light reactions occur? Where does the Calvin cycle occur? Where is NADPH and ATP released? Where is concentration of hydrogen and where is the ATP synthase?
I’ll Coit and buy liquid membrane, all rest stroma,
How does wavelength correlate with energy?
Smaller wavelength higher energy, Violet light almost 2 times more energy than red light
Electromagnetic spectrum: what’s the range of visible light, what are the wavelength measurements, where are the colour is situated?
380 nm 759 nm, purple is 380 red is 750
What’s a photon
Particle of light energy with specific wavelengths, particle and wave properties
What range on the electromagnetic spectrum does photosynthesis use? Explain the action spectrum for chloroplasts using the three pigments of chlorophyl a, chlorophyl B, and carotenoids.
Visible light
Chlorophyl a absorbs purple and orange light, chlorophyl be absorbs purple blue and orange red light, carotenoids absorb purple blue blueish green light. Green light is not absorbed and reflected so plants appear green.
Theodore W Engleman experiment of action spectrum for chloroplasts
Used aerobic bacteria growth on the filament of algae to determine oxygen output for determining amount of photosynthesis happening at specific wavelengths
What’s the difference between chlorophyl a and chlorophyl B
Chlorophyll eight is a blue green cloth B is olive green, chlorophyll a absorbs less than chlorophyll bees range. Chlorophyll eight is the key like caption pigment, chlorophyll B is an accessory pigment.
What role do carotenoids play in photoprotection
They absorb anticipate excessive light energy that would otherwise damage chlorophyl or form reactive oxidative molecules when interacting with oxygen, also protective role in human eye
What happens when chlorophyl absorbs light
One electron is elevated to an orbital with more potential energy, pigment is in excited state. Ground state is original electron location. Excited state is highly unstable, most electrons drop back down releasing energy as heat, photons given off creating florescence (red yellow glow)
Explain the structure of a photosystem
Reaction centre complex: special pair of chlorophyll a molecules, primary electron acceptor, chlorophyl boost electron to higher level
Harvesting complex: various pigment molecules bound to proteins (antenna), pigments transfer their energy to other pigments instead of boosting electron
How are deoxidized pair of chlorophyl molecules in the reaction centre complex a photosystem one replenished
By the splitting of water, it gets its electrons with hydrogen
What are the reaction centre chlorophyl is a photosystem one and photosystem two
Photosystem two is P6 80 photosystem one is P 700, those are the best wavelengths for absorption
Briefly summarize the steps of linear electron flow
- photon excites electron in pigment of light harvesting complex of PS2 boosting at a higher level drops giving energy to a neighbour pigment. Finally reaches P 60 pair of chlorophyl a and PS 2 Reaction Centre complex, excites into higher energy state
- P680 passes off electron is left oxidized as P680+
(Enzyme catalyzed water splitting: two electrons to hydrogen ions in an oxygen atom) - 680+ pear takes each electron, strongest oxidizing agent known in bio, The separate oxygen produced from two water molecules splitting combine to make O2
- electron transport chain between PSII and PSI, Electron carrier Pq (plastoquinone), sacrum complex, proteins Pc (plastocyanine): electron to drop in potential energy pumps hydrogen to eventually power ATP synthase
- light excites light harvesting complexes of PSI, P700 loses electrons to primary electron acceptor, P700+ draws electron from ECT
- PSII’s bottle excited electrons go through second ETC, use protein ferredoxin (Fd), no proton gradient no ATP made. Enzyme NADP+ reductase transfer e- fro Fd to NADPH (remove H+ from stroma too) (NADPH later use in Calvin cycle.
Explain cyclic electron flow
- photosystem one not two
- electrons cycle back from Fd to first cytochrome complex the back to P700 chlorophyll in reaction-center complex
- generates ATP in ETC, but no NADPH or O2
- evolutionary leftover, possibly photoprotective (low light good)
