bio chp. 8
chloroplast
(in green plant cells) a plastid that contains chlorophyll and in which photosynthesis takes place.
Proton gradient
According to the chemiosmotic hypothesis, what provides the energy that directly drives ATP synthesis?
These pigments are able to absorb more wavelengths of light (and thus more energy) than chlorophyll a alone can absorb. As part of light-harvesting complexes in photosystems, they broaden the range of light that can be used in the light reactions.
An action spectrum plots the rate of photosynthesis at various wavelengths of visible light, and it shows that blue light with a wavelength of about 490 nm is effective in driving photosynthesis. Based on this information and the absorption spectra shown at left, what role may chlorophyll b and carotenoids play in photosynthesis?
435 nm
Approximately what wavelength of light is best absorbed by chlorophyll a, the pigment that participates directly in the light reactions?
One cannot tell from this graph, but because chlorophyll a does absorb red light, we can predict that it would be effective in driving photosynthesis.
Can you tell from these absorption spectra whether red light is effective in driving photosynthesis?
photosystems
Chlorophyll can be found in _____.
ATP will not be produced because there is no ADP and inorganic phosphate in the solution.
Chloroplast membrane vesicles are equilibrated in a simple solution of pH 5 . The solution is then adjusted to pH 8 . Which of the following conclusions can be drawn from these experimental conditions?
thylakoid
Each of a number of flattened sacs inside a chloroplast, bounded by pigmented membranes on which the light reactions of photosynthesis take place, and arranged in stacks or grana.
photosystem I
Energized electrons from ____ enter an electron transport chain and are then used to reduce NADP+.
The graph indicates that chlorophyll a absorbs very little blue light, so we can predict that blue light would not be effective.
If only chlorophyll a were involved in the light reactions, would blue light (wavelength about 490 nm) be effective in driving photosynthesis?
water ... NADPH
The light reactions of photosynthesis use _____ and produce _____.
false
True or false? The chemiosmotic hypothesis states that the synthesis of ATP generates a proton gradient that leads to electron flow through an electron transport chain.
false
True or false? The region of ATP synthase that catalyzes the production of ATP from ADP and inorganic phosphate spans the chloroplast membrane.
6 CO2 + 6 H2O → C6H12O6 + 6 O2
What is the equation for photosynthesis?
stroma
Where does the Calvin cycle occur?
protons
Which of the following particles can pass through the ATP synthase channel?
ATP synthase phosphorylates ADP.
Which of these phosphorylates ADP to make ATP?
Photophosphorylation
Which term describes ATP production resulting from the capture of light energy by chlorophyll?
455 nm
Which wavelength of light is best absorbed by chlorophyll b?
They absorb blue/green light and reflect yellow and red wavelengths of light.
You obtain the pigments called carotenoids in your diet when you eat carrots. Why do carotenoids appear yellow and orange?
red, green
_____ has a longer wavelength than _____.
electrons
_____ releases energy that is used to pump hydrogen ions from the stroma into the thylakoid compartment.
photosystem II
_____ splits water into 1/2 O2, H+, and e- .
