Biochemistry : Photosynthesis
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Example Question #1 : Light Reaction Energetics
In photosynthesis, what is the purpose of absorbing light into chloroplasts?
The energy from the absorbed light generates NADPH from the electrons of water molecules, ultimately leading to the creation of carbon dioxide
The energy from the absorbed light generates NADPH from the electrons of water molecules, ultimately setting up a proton gradient
The energy from the absorbed light causes all of the electrons in the chloroplast to jump to higher energy levels
The energy from the absorbed light moves the electrons from NADPH to water molecules, ultimately setting up a proton gradient
The energy from the absorbed light causes the generation of NADH from the electron of water molecules, ultimately setting up a proton gradient
The energy from the absorbed light generates NADPH from the electrons of water molecules, ultimately setting up a proton gradient
In photosynthesis, light is absorbed in order to move electrons from water molecules to NADPH. The reduction of 
Example Question #1 : Light Reactions
Photosynthesis consists of a light phase and a dark phase. The light phase precedes the dark phase and supplies it with __________.
During photosynthesis, the light phase is responsible for creating 
Example Question #1 : Other Light Reaction Concepts
In photosynthesis, if photosystem II absorbs 12 photons, how many molecules of 
Absorbing four photons by photosystem II creates one oxygen molecule, so absorbing 12 would produce 3 molecules of 
Example Question #2 : Light Reactions
During photosynthesis there is both a light phase and a dark phase. If the light phase were to continue unabated, but the dark phase came to a halt, which of the following is most likely to occur?
A proportional decrease in 
Decrease in the level of
An increase in the production of carbohydrates
Decreased sensitivity of the chloroplast to incoming light
Increased sensitivity of the chloroplast to incoming light
Decrease in the level of
During photosynthesis, the dark phase follows the light phase. The light phase produces 
Carbohydrate production is a result of the dark phase working properly, so their levels would decrease in this instance. The sensitivity of the chloroplast to light would not change.
Example Question #1 : Calvin Cycle
What happens during stage 1 of the Calvin cycle?
Carbon dioxide and ribulose 1,5-bisphosphate react to form 3-phosphoglycerate
2 ATP molecules react with 3-phosphoglycerate to form 1,3-bisphosphoglycerate
NADPH and 1,3 bisphosphoglycerate react to form glyceraldehyde-3-phosphate
Fructose-6-phosphate becomes ribulose 5-phosphate
ATP reacts with ribulose 5-phosphate to become ribulose 1,5-bisphosphate
Carbon dioxide and ribulose 1,5-bisphosphate react to form 3-phosphoglycerate
All of the answer choices are steps in the Calvin cycle, but the only one that describes the first stage - fixation - is 
Example Question #4 : Carbohydrate Metabolism
What are the three stages of the Calvin cycle?
Fixation, carboxylation, and regeneration
Fixation, reduction, and regeneration
Reduction, oxidation, and regeneration
Fixation, oxidation, and regeneration
Carboxylation, reduction, and regeneration
Fixation, reduction, and regeneration
The stages of the Calvin cycle in the order that they occur are fixation, reduction, and then regeneration. While carboxylation does occur as a part of the first stage, it is not what defines that stage.
Example Question #2 : Carbohydrate Metabolism
Which of the following is not true of the Calvin cycle?
NADPH and ATP are required to initiate the Calvin cycle
All of these are true of the Calvin cycle
The Calvin cycle does not need light to function
The Calvin cycle occurs in the stroma of a chloroplast
The first step of the Calvin cycle is carbon fixation
The Calvin cycle does not need light to function
Despite the Calvin cycle's other name (light independent reactions), light is indirectly required for this process to function. All other choices are true of the Calvin cycle.
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