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Example Questions
Example Question #1 : Cellular Energetics
Given the hydrolysis of 1 mole of , which reaction could be driven by hydrolyzing 2 moles of ATP?
Given that the hydrolysis of 1 mole of ATP has delta G of , if 2 moles of ATP are hydrolyzed, delta . Reaction D has a delta G of ; when coupled with the hydrolization of 2 moles of ATP, delta G will be . As this is negative, it is indicated that this will be a spontaneous reaction, or can proceed without input of energy.
Example Question #2 : Cellular Energetics
ATP coupling describes the process through which hydrolysis of ATP can drive a __ reaction
thermodynamically unfavorable
exothermic
spontaneous
thermodynamically favorable
thermodynamically unfavorable
ATP coupling is the process where hydrolysis of ATP (a thermodynamically favorable, negative delta G, or spontaneous reaction) is coupled with a thermodynamically unfavorable reaction (a reaction that cannot proceed without energy input).
Example Question #3 : Cellular Energetics
Which of the following is an endergonic reaction?
Na+/K+ pump
Cellular respiration
Catabolism
Hydrolysis of ATP
Na+/K+ pump
An endergonic reaction requires input of energy; delta G will be positive. Hydrolysis of ATP, cellular respiration, and catabolism (breakdown of a large molecule) are exergonic processes. The Na+/K+ pump is endergonic, as it requires energy. This process is coupled with ATP hydrolysis to allow it to proceed.
Example Question #4 : Cellular Energetics
Which is true of an exergonic reaction?
Energy is required
The reaction will always be endothermic
The reaction will not occur spontaneously
Energy is released
Energy is released
Exergonic reactions are reactions that release energy. Endergonic reactions are reactions that require energy to proceed. Exergonic reactions can occur spontaneously, or are thermodynamically favorable. Endergonic reactions cannot occur spontaneously, or are thermodynamically unfavorable.
Example Question #5 : Cellular Energetics
ATP phosphorylation (ADP+ Pi-> ATP+ H2O) is what type of reaction?
spontaneous
exergonic
endergonic
catabolic
endergonic
ATP hydrolysis is exergonic. ATP phosphorylation is the reverse of ATP hydrolysis, and thus is endergonic.
Example Question #6 : Cellular Energetics
If the reaction for ATP hydrolysis is coupled with the reaction glucose+ sucrose-> fructose,, what is the net delta G?
Through ATP coupling, the hydrolysis of ATP can allow the second, thermodynamically unfavorable reaction to proceed. . As the resulting delta is negative, this will be thermodynamically favorable.