Chapter 9
During which phase of photosynthesis is ATP and NADPH synthesized?
light-dependent phase
A chlorophyll molecule has a porphyrin ring containing a single atom of:
magnesium
What are the reactants of the light-dependent reactions of photosynthesis?
H2O, ADP, and NADP+
A group of thylakoid discs make up what part of a chloroplast?
granum
What are the major events that occur during the light-dependent reactions of photosynthesis?
light capture, oxidation of water, reduction of NADP+, and formation of ATP
The graph in the accompanying figure represents the:
absorption spectra for chlorophylls a and b
Which plant keeps its stomata open only at night?
orchid
The synthesis of ATP during photosynthesis or respiration occurs as a result of what process?
phosphorylation of ADP
Which process not only yields electrons during photosystem I and II, but also is the source of almost all the oxygen in Earth's atmosphere?
photolysis
The energy of a(n) ____ is inversely proportional to its wavelength.
photon
What are the packets of kinetic energy in light called?
photons
Which photosynthetic unit consists of a pair of chlorophyll a molecules with an absorption peak of 700nm?
photosystem I
By definition, substances that absorb visible light are called:
pigments
Which part of the chlorophyll molecule is responsible for absorbing light?
porphyrin ring
Each antenna complex absorbs light energy and transfers it to its reaction center, which consists of chlorophyll molecules and ____.
proteins
According to the graph in the accompanying figure, chlorophyll absorbs light most strongly in what region of the electromagnetic spectrum?
red and blue wavelengths
A proton gradient is established across the thykaloid membrane when protons diffuse from ________.
stroma to, thykaloid lumen
What color does chlorophyll reflect?
green
If the energy source for the light-dependent reaction of photosynthesis is sunlight, then what energy is needed to fuel the carbon fixation reaction?
ATP and NADPH
How many carbon fixation reactions make up the Calvin cycle?
13
How many reactions take place during the Calvin cycle?
13
How many electrons are needed to reduce one molecule of NADP+ to NADPH?
2
Carbon is fixed in which part of the accompanying diagram?
4
Which best summarizes the overall reactions of photosynthesis?
6 CO2 + 12 H2O → C6H12O6 + 6 O2 + 6 H2O
Which is the correct reaction for photosynthesis?
6CO2 + 6H2O → C6H12O6 + 6O2
Thylakoid membranes are involved in ____ synthesis.
ATP
Why do algae in our oceans play an important role in climate change?
Algae helps reduce CO2 in the atmosphere to utilize in photosynthesis.
The enzyme rubisco combines ribulose bisphosphate with carbon from what molecule?
CO2
What is the first step in the Calvin cycle?
CO2 attaches to RuBP
What is the ultimate source of electrons for noncyclic electron transport, and thus photosynthesis?
water
What is an end product of photosystem I?
NADPH
What is a metabolic difference between a photoautotoph and a photoheterotroph?
Photoheterotrophs do not carry out carbon fixation.
Why does red and blue light support the highest rates of photosynthesis?
These wavelengths are absorbed by chlorophyll more than any other wavelength.
ATP synthesis during the light-dependent reactions occurs by which process?
chemiosmosis
The primary pigment needed for photosynthesis is ________.
chlorophyll a
Which type of electromagnetic waves have the shortest wavelength?
gamma waves
Engelmann concluded that chlorophyll in the chloroplasts is responsible for photosynthesis based on the which of the following results?
he action spectrum of photosynthesis matched the maximum production of oxygen by Spirogyra, with the greatest accumulation of bacteria in the blue and red regions of the spectrum.
ATP is formed when ____ the thylakoid lumen.
hydrogen ions leave
Photosystem I and photosystem II take place during what part of photosynthesis?
light-dependent reaction
In C3 plants, the ____ are typically closed at night and open during the daytime to allow for gas exchange.
stomata
In which part of the chloroplast do the carbon fixation reactions take place?
stroma
The carbon fixation reaction occurs in what part of a chloroplast?
stroma
What is the fluid-filled sac within the inner membrane of a chloroplast called?
stroma
Where is the electron transport chain of photosynthesis located?
thylakoid membrane
What type(s) of wavelengths is emitted by the sun?
visible, ultraviolet and infrared waves