BIOCHEMISTRY
ENZYMES AND METABOLISM
|
Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
|
|
|
larger molecules are made from smaller starting molecules
|
|
|
endergonic reactions are coupled to exergonic reactions from the release energy from NADPH and ATP
|
|
|
overall, the synthesis of sugar from CO2 is endergoncic
|
|
|
100% of the energy in ATP and NADPH is converted into stored energy in glucose
|
Detailed explanation-1: -The dark reactions use the ATP and NADPH produced during the light reactions for energy, since these reactions do not use any energy from sunlight. The Calvin cycle, which is another name for the dark reactions of photosynthesis, consists of three steps: carbon fixation, reduction, and regeneration.
Detailed explanation-2: -Some Calvin cycle reactions require ATP (adenosine triphosphate), a compound that functions in energy transfer, and NADPH (reduced nicotinamide adenine dinucleotide phosphate), a source of hydrogen atoms for reduction reactions. ATP and NADPH are formed during light-energized reactions of photosynthesis.
Detailed explanation-3: -ATP and NADPH produced by the light reactions are used in the Calvin cycle to reduce carbon dioxide to sugar. The Calvin cycle is similar to the Krebs cycle in that the starting material is regenerated by the end of the cycle.
Detailed explanation-4: -In the second stage, ATP and NADPH are used to convert the 3-PGA molecules into molecules of a three-carbon sugar, glyceraldehyde-3-phosphate (G3P). This stage gets its name because NADPH donates electrons to, or reduces, a three-carbon intermediate to make G3P.