BioChem Final Review Photosynthesis/Calvin cycle
What supplies the electrons to the Calvin cycle?
NADPH
Which substances from the light-dependent reactions of photosynthesis is a source of energy for the Calvin cycle?
NADPH
Two interdependent processes which comprise photosynthesis are (1) the formation of carbohydrates from CO2 and (2) the formation of what?
NADPH and ATP
What are the reactants in the Calvin cycle?
NADPH, G3P, ATP, CO2
How many PGALs are needed to create one glucose?
2
How many carbons does G3P have?
3
What is the product of the reaction catalyzed by rubisco in the Calvin cycle?
3-phosphoglycerate
Photosystem II absorbs maximally at what?
680 nm
Photosystem I absorbs maximally at what?
700 nm
Describe the Calvin cycle.
ATP and NADPH produced by the light reactions are used by the Calvin cycle to make carbohydrates.
What supplies the electrons to photosystem I?
Electron transport from photosystem II
True or False, Chlorophyll is found in the mitochondria.
False
True or False, Most plants are heterotrophic.
False
True or False, Oxygen and water, in the presence of sunlight, will react to form glucose and carbon dioxide gas.
False
True or False, Plant cells have a large vacuole instead of a Golgi apparatus.
False
True or False, The only difference between a plant cell and an animal cell is that plant cells have chloroplasts.
False
True or False, oxygen is a reactant of the Calvin cycle.
False
In plants, light energy channeled to PSII and PSI drives electron transport through a series of electron carriers. At the same time, protons are translocated into the what?
Lumen
In cacti what accumulates in the cell vacuoles at night that is released in the day and decarboxylated?
Malate
The initial reactions of the C4 pathway occur in the what?
Mesophyll cells
The nocturnal fixation of carbon dioxide in cacti helps what?
Minimize water loss
A structure within a cell that performs a specific function is called a what?
Organelle
As a result of photosynthesis, what is released into the atmosphere?
Oxygen
Photosynthesis enables plants to produce most of the glucose that they need. What is not required for photosynthesis to take place?
Oxygen
The major atmospheric byproduct of photosynthesis is what?
Oxygen
What are the products of photosynthesis?
Oxygen and Glucose
What does RuBP stand for?
Ribulose bisphosphate
When carbon first enters the Calvin cycle, what molecule does it combine with?
RuBP
The enzyme ______ joins RuBP to CO2
Rubisco
What is the enzyme used in C3 Calvin Cycle?
Rubisco
What is the name of the enzyme that fixes carbon in photosynthesis?
Rubisco
What happens in RuBP regeneration?
Some G3P molecules that are produced go on to make glucose, and others must be recycled to regenerate the RuBP acceptor for the Calvin cycle to continue.
Where do the light-independent reactions occur?
Stroma
Where does the Calvin cycle occur?
Stroma
Where in a chloroplast does the light-independent reaction take place?
Stroma
What is the benefit of the CAM adaptation?
Temporal separation of carbon fixation and Calvin cycle
What is the main advantage for plants that use the C4 pathway in addition to the Calvin cycle for the fixation of carbon dioxide?
The C4 pathway aids in the avoidance of the oxygenation of ribulose 1,5-bisphosphate.
The photosynthetic dark reactions do what?
convert carbon dioxide to carbohydrates
The formation of ATP is a what reaction in plants?
light dependent
Photorespiration in plants involves the ________.
light-dependent uptake of O2 catalyzed by rubisco, followed by the release of CO2
Which molecule is the CO2 acceptor in the first step of the Calvin cycle?
ribulose 1,5-bisphosphate
Which reactant of photosynthesis is used in the light independent reactions?
CO2
What are the two reactants of carbon dioxide fixation?
CO2 and ribulose bisphosphate
Carbon dioxide is used in the what?
Calvin cycle
Takin in CO2 from the atmosphere and turning it into glucose is called what?
Carbon Fixation
To bring in CO2 and use it to make organic compounds is called what?
Carbon Fixation
What is not a product of the Calvin Cycle?
Carbon dioxide
What happens in Carbon reduction?
Carbon dioxide is fixed and reduced in order to form G3P.
Name the reactions that occur during the Calvin cycle.
Carbon reduction, RuBP regeneration and Carbon fixation.
Give the correct order for the stages in the Calvin cycle.
Carboxylation -> Reduction -> Regeneration
What is the correct order of the organization of structures in living things, from simplest to most complex? ( tissues, cells, organs, systems, organisms, organ systems)
Cells, Tissues, Organs, Organ Systems, Organism
Which of the following is able to build fuel molecules without use of light energy (using energy sources such as H2S, NH3, or Fe+2)?
Chemoautotrophs
Two activators must be present in order for photosynthesis to take place in green plants. The activators are what?
Chlorophyll and Sunlight
What is not a photosynthetic pigment found in plants? (Chlorophyll a, b, or c)
Chlorophyll c
The organelles in plant cells that contain a green pigment and are associated with photosynthesis are the what?
Chloroplasts
The reactions that allow plants such as cacti and orchids to assimilate carbon at night are referred to as what?
Crassulacean act metabolism
When ATP runs short, a chloroplast why revert to what to generate a few additional ATP to balance out the stoichiometry of the reaction?
Cyclic Phosphorolation
What is the benefit of the C4 adaptation?
Decrease photorespiration
What represents the relationship between the light reactions and the Calvin cycle?
The light reactions provide ATP and NADPH to the Calvin cycle which returns ADP, Pi, and NADP+
Within the chloroplasts, grana are what?
The storma
Based on the cycle of photosynthesis and cellular respiration, one can say that the ultimate original source of energy for all living things on Earth is what?
The sun
What limits the Calvin Cycle?
Amount of carbon dioxide
What limits light reactions?
Amount of light
Is photosynthesis catabolic or anabolic?
Anabolic
A mutation occurs in the chloroplasts of a lettuce plant, causing its thylakoid membranes to becomes more permeable to charged ions. How might this mutation affect the Calvin cycle?
Fewer carbohydrates would be produced by the Calvin cycle. Less carbon fixation would occur in the treated chloroplasts because less ATP would be created due to the weaker proton gradient across the thylakoid membrane.
What sugar is produced by the Calvin Cycle?
G3P
Stomata are the sites of the what?
Gas exchange
What is the name of the simple sugar that is produced in photosynthesis?
Glucose
Most plants don't absorb ________ light.
Green
Organs associated with photosynthesis are what?
Green leaves
In the Z scheme describing electron flow in photosynthesis the electron donor to P680 is _______, while the electron donor to P700 is ________.
H2O; plastocyanin
How did Van Niel track atom movements of photosynthesis?
Isotope labeling and Mass spectroscopy
Sunlight is used in the what?
Light reactions
What replaces rubisco in a C4 reaction?
Pep carboxylase
The initial carbon dioxide acceptor of the C4 pathway is what?
Phosphoenolpyruvate
The process whereby plants capture energy and make complex molecules is known as what?
Photosynthesis
The production of O2 from water supplies an electron first for what?
Photosystem II
Which type of cells can undergo photosynthesis?
Plant cells
Electron carriers between activated P680 and P700 photosystems include what?
Plastoquinones and Pheophytin
What allows chlorophyll to absorb light energy (photons)?
Porphyrin ring
What is the purpose of cyclic electron flow?
Produce more ATP
The primary electron acceptor is a __________ molecule.
Quinone
In the C3 cycle, PGA is reduced or oxidized into PGALs
Reduced
The Calvin cycle is considered light-independent because it can occur in darkness. However, most often the Calvin cycle takes place in sunlight. Explain why this happens.
The Calvin cycle requires ATP and NADPH which requires sunlight ti be produced.
The primary function of roots is what?
The absorption of water and minerals
Light reactions occur in the ______ while the calvin cycle occurs in the _______.
Thylakoid membrane, stroma
What is the main purpose of the light reactions?
To provide the energy and electrons for the Calvin cycle
Photosynthetic organisms are what?
Trees
True or False, All organisms require energy to carry out life processes.
True
True or False, Bromothymol blue solution will change form blue to yellow when carbon dioxide gas is added.
True
True or False, NADP+ is not required to activate rubisco.
True
True or False, Photosynthesis is a process that takes place in autotrophs.
True
True or False, The major light-absorbing pigment in plants in chlorophyll.
True
True or False, the Calvin cycle can happen at night.
True
True or False, the Calvin cycle can happen during the day.
True
Plant cells have large membrane-bound spaces in which water, waste products, and nutrients are stored. These places are known as what?
Vacuoles
What is not a product of light reactions?
Water
What supplies the electrons to photosystem II?
Water
Give the correct sequence for the following components in photosynthesis as described by the Z scheme?
Water -> P680 -> cytochrome bf complex -> P700 -> NADPH
The two main reactants of photosynthesis are what?
Water and CO2
