8.2
After absorbing the energy from light, chlorophyll in the reaction center becomes
a strong electron donor
process of carbon fixation
carbon dioxide is incorporated into a molecule of ribulose biphosphate forming an unstable 6 carbon intermediate that immediately splits into two 3-carbon molecules.
During the light dependent reactions of photosynthesis, an excited electron is transferred from chlorophyll in the reaction center to an acceptor molecule; this stage in the thylakoid reactions is also known as
charge seperation
ATP is synthesized during the fourth stage of the thylakoid reactions, also known as the
chemiosmosis stage
Which of the following are used to synthesize carbohydrates in photosynthesis?
co2 NADPH, ATP
Protons are pumped across the thylakoid membrane of the chloroplast during the _________ __________ stage of the thylakoid (or light-dependent) reactions.
electron transport
In the reaction center of a photosystem, which of the following excited subatomic particles are transferred to an acceptor
electrons
Glyceraldehyde 3-phosphate formed during the Calvin cycle is an important compound in which of the following stages of cell respiration?
glycolysis
A key difference between PSII and PSI is
how they transfer their electrons how their pigments receive electrons
what light reaction occurs in the thylakoid membrane
light dependent reaction
In the reaction center of PSII, chlorophyll removes an electron from an atom of ______________ which in turn removes an electron from an _______________ atom in a water molecule.
manganese, oxygen
In chloroplasts, electrons ejected from the photosystems do not return to them, which is known as:
noncyclic photophosphorylation.
Roughly equal amounts of NADPH and ATP are generated in
noncyclic photophosphorylation.
The path of electrons from water through PSII and PSI and ultimately to NADPH is also know as
noncyclic photophosphorylation.
During the primary photoevent ___________ of light is captured by a pigment.
photon
Similar to ATP synthesis in mitochondria, ATP synthesis in chloroplasts is achieved by a chemiosmotic mechanism called
photophosphorylation
Which photosystem's main function is to generate high-energy electrons for the synthesis of ATP?
photosystem II
Almost all photosynthetic organisms capture light using:
photosystems
The reaction center in chloroplasts is a transmembrane _____________-pigment complex.
protein
The abbreviation, RuBP, stands for ___________ 1,5-bisphosphate.
ribulose
As protons pass through the ATP synthase channels, ADP is phosphorylated to ATP and released into the ___________ of the chloroplast.
stroma
Most plants combine glucose and fructose to produce ________ which is the major transport sugar
sucrose
Most plants transport the fixed carbon in the form of the transport sugar:
sucrose
In the chloroplasts of green plants, the splitting of water, the transfer of high energy electrons from PSII to PSI, and the formation of NADPH all contribute to Blank______.
the generation of a H+ gradient
The excited chlorophyll in the reaction center transfers its electron to
the primary acceptor
The ATP synthase enzymes of chloroplasts are located in the:
thylakoid membrane
How many bacteriochlorophyll a molecules are located in the reaction center of purple photosynthetic bacteria?
two
What is the net gain of the Calvin cycle?
two molecules of g3p
1. Primary photo event 2. .charge seperation 3. electron transport 4. chemiosmosis
1. A photon of light is captured by a pigment. The primary photoevent excites the electron with the pigment 2. charge separation- this exception energy is transferred to the reaction center, which transfers an energetic electron to an acceptor molecule, initiating electron transport 3. electron transport- the excited electrons are shuttled along a series of electron carrier molecules embedded within in photosynthetic proton gradient. the electrons are used to reduce the final acceptor, NADPH 4. Chemiosmosis- the proton gradient is a form of potential energy that can be used by and ATP synthase enzyme that catalyzes the reaction of ADP and Pi to form ATP. This enzyme is evolutionarily related to the mitochondrial enzyme with the same function
Order the phases of the Calvin cycle in the correct order from first (on top) to last.
1. carbon fixation 2. reduction carbohydrate production 3. regeneration of ribulose bisphosphate
Consider the net equation that describes the Calvin cycle. How many NADPH are needed to synthesize the two net G3P molecules that can be used to make a glucose molecule
12
When you take into account the net equation of the Calvin cycle, how many ATP molecules are needed to synthesize two G3P molecules?
18
How many molecules of reduced ferredoxin are needed to make one molecule of NADPH during photosynthesis in plants?
2
If the Calvin cycle is performed 12 times, it will produce ______ net molecule(s) of G3P.
4
During the splitting of water by PSII, ______ manganese atoms and ______ water molecules are bound to the reaction center.
4, 2
photosystem 1 absorption peak is ______ photosystem 2 absorption peak is __________
700 nm, 680 nm
Plant cells can produce additional amounts of ____________ to fuel the Calvin cycle in a process known as cyclic photophosphorylation.
ATP
Photophosphorylation produces ________ which stores chemical energy that can be used for the Calvin cycle. Carbon fixation also requires reducing power, which is provided by ___________ produced by photosystem I.
ATP, NADPH
The electron transport chain directly associated with photosystem II is used to generate ______, while the electron transport chain directly associated with photosystem I is used to generate ______.
ATP, NADPH
What occurs during the charge separation stage of the thylakoid reactions
An excited electron is transferred out of the photosystem.
In a photosystem the ___________ complex captures light energy and passes it to the ________________ center where electrons are transferred out of the photosystem.
Antenna, reaction (the two components a photosystem consists of)
If the light-dependent reactions produce roughly equal amounts of ATP and NADPH, how can plant cells ensure that there is enough ATP for the Calvin cycle?
By using cyclic photophosphorylation
In the light reactions, ATP is generated via
Chemiosmosis
Choose all three statements about Rubisco.
It is a large enzyme made of 16 subunits. It might be the most abundant protein on Earth. It works very slowly.
How is the reaction center positioned in the membrane?
It is a transmembrane complex
Which of the following happens to the molecule formed by the addition of carbon dioxide to ribulose bisphosphate?
It is immediately split into 2 more stable three carbon molecules
that catalyzes the reduction of NADP+ to NADPH in chloroplasts is called
NADP reductase
During the electron transport stage of the thylakoid reactions electrons are shuttled along a series of electron carrier molecules, eventually reaching the final acceptor. This final acceptor is
NADPH
Which of the following is the source of electrons used to reduce C—O bonds in the Calvin cycle?
NADPH
Which product of the light reactions of photosynthesis is the source of electrons in the Calvin cycle?
NADPH
In all photosynthetic organisms studied to date, except one class of photosynthetic bacteria, light is captured by clusters of chlorophyll and accessory pigment molecules, which together are called
Photosystems
In the Calvin cycle CO2 is attached to an organic molecule abbreviated as
RUbP
The enzyme that catalyzes the transfer of CO2 to a molecule of RuBP is called:
Rubisco.
Which of the following processes contribute to the generation of a proton electrochemical gradient during photosynthesis
The movement of electrons from PSII to PSI The splitting of water
Which of these statements are true about the relationship between photosynthesis and cell respiration?
The products of cell respiration are the reactants of photosynthesis. The products of photosynthesis are the reactants of cell respiration.
