The Biosphere 2 project, in Tucson, Arizona, was an experiment involving a large sealed
terrarium with humans and photosynthetic plants living in balance. Why did the project have to
be interrupted after only a few months?
Levels of CO2 rose to dangerous levels.
The humans ran out of food.
The plants stopped producing oxygen.
The rate of photosynthesis was too high correct answers Levels of CO2 rose to dangerous levels
The __________ is driven directly by photo- ns from the sun in photosynthesis light reactions.
pumping of protons
synthesis of ATP
transfer of electrons
synthesis of glucose correct answers transfer of electrons
Heme and chlorophyll have similar overall structures. What is common between the two
molecules?
color
hydrophobic tail
polycyclic planar structure
metal ion found at their center correct answers polycyclic planar structure
Chlorophyll absorbs light energy efficiently because of the
metal ion in the center of the molecule.
ring structure.
planar structure.
alternating double and single bonds. correct answers alternating double and single bonds
Which of the following is a photosynthetic light harvesting pigment?
FeS cluster
NADPH
plastoquinone
β-carotene correct answers β-carotene
Approximately how many light-harvesting chromophores are found per photosystem enzyme,
such as in PSI or PSII?
2
about a dozen
about 100 to 200
,about 1000 to 2000 correct answers about 100 to 200
The following picture is an example of what phenomenon?
resonance energy transfer
electron transfer
photoexcitation
fluorescence correct answers resonance energy transfer
Which of the following is an electron transfer molecule in photosynthesis light reactions?
plastoquinone
photon
paraquat
ATP correct answers plastoquinone
The photosynthetic Z scheme describes the
synthesis of glucose from CO2.
movement of electrons driven by the absorption of light energy.
production of O2.
reduction of NADPH. correct answers movement of electrons driven by the absorption of light
energy
The primary difference between ATP synthesis during the photosynthetic light reactions and
ATP synthesis in the mitochondrial electron transport chain is the
cellular location of the proton motive force.
enzyme catalyzing the ATP synthesis.
number of ATP produced per 360 rotation of the F1 subunit of ATP synthase.
number of NADPH required to produce ATP. correct answers cellular location of the proton
motive force
In the chloroplasts, photosystem I (PSI) and photosystem II (PSII) are known to localize in
different regions. PSI generally localizes in the __________, whereas PSII localizes in the
__________.
thylakoid lumen, thylakoid grana
thylakoid lamellae, thylakoid grana
stroma, thylakoid lumen
thylakoid grana, thylakoid lamellae correct answers thylakoid lamellae, thylakoid grana
In what location of the cell does the Calvin cycle occur?
chloroplast grana
thylakoid lumen
chloroplast stroma
,cytoplasm correct answers chloroplast stroma
The Calvin cycle requires which species from the light reactions?
ATP and NADPH
reducing electrons
CO2 and ATP
NADH and FADH2 correct answers ATP and NADPH
The first stage of the three-stage Calvin cycle
generates CO2.
uses ATP and NADPH from the light reactions.
occurs in the plant cell cytoplasm.
is catalyzed by the enzyme rubisco. correct answers is catalyzed by the enzyme rubisco
The formation of one net glyceraldehyde-3-phosphate during the net Calvin cycle reactions
requires __________ NADPH and __________ ATP.
3, 3
3, 6
6, 6
6, 9 correct answers 6, 9
What is the name of the enzyme that catalyzes the reaction shown below?
ribulose bisphosphate carboxylase
acetyl-CoA carboxylase
glyceraldehyde-3-phosphate dehydrogenase
pyruvate carboxylase correct answers ribulose bisphosphate carboxylase
Transketolase requires the coenzyme
cobalamin (vitamin B12).
pyridoxal phosphate.
tetrahydrofolic acid.
thiamine pyrophosphate. correct answers thiamine pyrophosphate
Which cell type in C4 plants is isolated from O2 exposure as they perform Calvin cycle
reactions?
Hatch-Slack cells
bundle sheath cells
guard cells
mesophyll cells correct answers bundle sheath cells
, Which of the following is true of the glyoxylate cycle?
It allows plants to produce glucose from fats and two-carbon molecules like acetate.
It occurs in plant cells as an alternative to photosynthesis.
It bypasses all regulated steps of the TCA cycle.
It results in a net production of ATP and NADH without proceeding through the TCA cycle.
correct answers It allows plants to produce glucose from fats and two-carbon molecules like
acetate
The glyoxylate cycle reaction shown below is catalyzed by which enzyme class?
lyase
hydrolase
transferase
oxidoreductase correct answers lyase
Which of the following is classified as a monosaccharide?
sucrose
glucose
lactose
maltose correct answers glucose
One of the functions of simple sugars includes
enzymatically removing glycans through hydrolysis reactions.
functioning as a structural component in invertebrate exoskeletons.
acting as metabolic intermediates in energy conversion pathways.
enzymatically linking glycans to proteins and lipids. correct answers acting as metabolic
intermediates in energy conversion pathways
Which of the following oligosaccharides are found in high abundance in some types of
vegetables and have been known to cause intestinal distress?
lacto-N-tetraose
verbascose
amylose
amylopectin correct answers verbascose
The product Beano contains __________, which helps humans digest raffinose-series
oligosaccharides.
a-galactosidase
B-galactosidase
lactase
amylase correct answers a-galactosidase