Which equation shows how cells use the energy stored in an energy carrier?
A. [tex]$NADPH \rightarrow NADP ^{+}+ H ^{+}$[/tex]
B. [tex]$NADP ^{+}+ P \rightarrow$ ATP[/tex]
C. [tex]$ATP \rightarrow ADP + NADPH$[/tex]
D. [tex]$ADP + H ^{+} \rightarrow ATP$[/tex]
Answer (2)
The correct option that shows how cells utilize energy stored in energy carriers is Option C: A TP → A D P + N A D P H . This option represents the breakdown of ATP, which releases energy needed for cellular activities, even though it is not entirely accurate. The focus is on the energy release from ATP, which is how cells perform work.
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Cells use energy by breaking down ATP.
Option A shows NADPH releasing electrons, not direct energy use.
Options B and D show ATP formation (energy storage).
Option C, though not perfectly accurate, best represents ATP breakdown, so the answer is C .
Explanation
Understanding Energy Use in Cells We need to identify the equation that demonstrates how cells utilize the energy stored in an energy carrier. The key is to recognize that cells use energy by breaking down ATP (adenosine triphosphate).
Analyzing the Options Let's analyze each option:
A. N A D P H i g h t ha r p oo n u pN A D P + + H + : This equation represents the oxidation of NADPH. While NADPH is an energy carrier, this equation shows it releasing electrons, not directly powering cellular work.
B. N A D P + + P i g h t ha r p oo n u p A TP : This equation shows the formation of ATP, which is energy storage, not energy use.
C. A TP i g h t ha r p oo n u p A D P + N A D P H : This equation is incorrect . The correct breakdown of ATP is A TP i g h t ha r p oo n u p A D P + P i (inorganic phosphate) + energy. While this option is not perfectly accurate, it's the closest to showing ATP being broken down.
D. A D P + H + i g h t ha r p oo n u p A TP : This equation also shows the formation of ATP, which is energy storage, not energy use.
Determining the Correct Answer The best answer is the one that shows the breakdown of ATP to release energy, even if the products are not entirely correct. Therefore, the closest and thus the correct option is C.
Examples
Think of ATP as the cell's currency. Just like you spend money to buy goods or services, cells 'spend' ATP to power various processes like muscle contraction, protein synthesis, and nerve impulse transmission. The equation that shows ATP breaking down into ADP and releasing energy is like showing you spending money.
