Chapter 4 Flashcards
Give the general equation for photosynthesis
6CO2 + 6H2O + LIGHT ENERGY = C6H12O6 + 6 O2
what are the 2 basic reactions to photosynthesis, and where do they occur?
Light reaction: occurs in thylakoids. Splits water, release oxygen, produce ATP and NADPH
The Calvin Cycle: occurs in the stroma and cytosol. forms sugar from CO2, using ATP for energy and NADPH for electrons.
If seaweed appears to be red to us, what colors are being absorbed and which are reflected?
reflecting red light and absorbing blue light
what are the three categories of pigments that algae use?
chlorophylls, carotenoids, phycobiliproteins
Chlorophylls:
water insoluble, fat/lipid soluble. non-polar
Carotenoids:
water insoluble, fat/lipid-soluable (non polar)
carotene (red-orange), xanthophylls (brown-yellow)
fucoxanthin, diadinoxanthin, peridinin
Phycobiliproteins:
water soluble, fat insoluble (polar)
phycocyanin (blue-green) phycoerythrin (red)
photosynthesis:
converts solar energy into chemical energy
who are the producers of marine ecosystems?
algae and seagrasses
who are the producers of fresh water ecosystems?
algae and macrophytes
what are the three components of a chloroplast?
thylakoids, grana, stroma
where does the light reaction occur?
in the thylakoids
where does then calvin cycle occur?
in the stroma or cytosol (blue green algae in cytosol, b/c of no thylakoids)
which has less energy, long or short waves?
long wavelengths
PAR
photosynthetically active radiation
why cant you see shadows under water?
because water is light scattering
what angle of incidence is critical for 100%?
90degrees
what three things can happen when light meets matter?
absorb, reflected, transmitted
Pigments:
substances that absorb visible light
what measure of wavelength has the most transmittance?
550nm
how can algae respond to low/high light levels?
can produce more/ lose pigments, or create protective pigments
What is the photosystem comprised of?
a reaction center surrounded by a number of light harvesting complexes
what are the ‘light harvesting complexes’ found within the photosystem?
pigment molecueles bound to particular proteins, who funnel energy to reaction center.
name some types of chlorophyll pigments:
a, b, c1, c2, d
name some types of carotenoid pigments
carotene (red-orange), xanthophylls (brown-yellow), fucoxanthin, diadinoxanthin, peridinin
name some phycobilliprotein pigments
phycocanin (blue-green), phycoerythrin (red)
what is chromatic adaptation?
the ability to adjust their concentration of pigments. Respond to high vs low light, tremendous phenotypic plasticity
what are the three G’s of algae photosynthetic products?
Glucose polymers: amylose, starch, cellulose
Glucans: laminarin, chrysolaminarin
Galactans: agar, carageenan
How deep can you find Rhodophyta?
in over 800m of water
Whad to you call a short daylight photoperiod responce?
foliose phase
what do you call a long daylight photoperiod responce?
conchocelis phase
Photoautotroph
use the energy of sunlight to make organic molecules from water and carbon dioxide
Chloroplasts:
organelles of photosynthesis consist of thylakoids, grana, stroma
Pigments:
cubstances that absorb visible light (phycobilliproteins, carotenoids, chlorophylls)
Acessorty Pigments:
Absorb different wavelengths of light and pass the energy to chlorophyll-a
Photoperiod responses:
control some aspect of a life cycle by the timing of light and darkness
what are the three phases that occur in the STROMA?
- carbon fixation (adding carbon from carbon dioxide to a molecule)
- Reduction: (addition of electrons from ATP and NADPH molecules)
- REGENERATION of the CO2 acceptor molecule
Absorption spectrum
The range of frequencies of electromagnetic radiation readily absorbed by a substance by virtue of its chemical composition
Photic Zone
is the depth of the water in a lake or ocean that is exposed to sufficient sunlight for photosynthesis to occur.
Reaction Center
Surrounded by several light harviesting complexes, the reaction center is an organized association of proteins holding a special pari of chlorophyll molecules.
Cyclic Electron Flow
a route of electron flow during the ight reactions of photosynthesis that involves only photosystem 1 and that produces ATP but not NADPH or O2
ATP synthase
a complex of several membrane proteins that functions in chemiosmosis with adjacent electron transport chains, using the energy of a hydrogen ion concentration gradient to make ATP. ATP synthases are found in the inner mitrochondrial membranes of eukaryotic cellls and in the plasma membranes of prokaryotes.
Carbon Fixation
the initial incorporation of carbon from CO2 into an organic compound by an autotroic organism ( a plant, another photosynthetic organism, or a chemoautotrophic prokaryote).
