Question

the chemical formula for glucose, a simple sugar, is c6h12o6. when a glucose molecule is assembled during photosynthesis, the process takes up 12 hydrogen ions from the stroma of the chloroplast.

what process adds 12 hydrogen ions to the chloroplast?
standard addressed:

other sugar molecules reacting with oxygen in the chloroplast
12 water molecules splitting apart during the light-independent reactions
6 water molecules splitting apart during the light-dependent reactions
12 water molecules splitting apart during the light-dependent reactions

Explanation:

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"concepts_used": [
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"new_concepts": [
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"Photosynthesis Reactions",
"Light-Dependent Reactions",
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"Photosynthetic Stoichiometry"
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<reasoning>

Identify the source of hydrogen ions

Using the Photosynthesis Reactions knowledge point
\[
2\text{H}_2\text{O}
ightarrow 4\text{H}^+ + 4e^- + \text{O}_2
\]

Calculate the required water molecules

Using the Light-Dependent Reactions knowledge point
\[

$$\begin{aligned} &\text{Ratio: } \frac{2\text{ H}_2\text{O}}{4\text{ H}^+} = \frac{1\text{ H}_2\text{O}}{2\text{ H}^+}\\ &x\text{ H}_2\text{O} = 12\text{ H}^+ \times \frac{1\text{ H}_2\text{O}}{2\text{ H}^+} = 6\text{ H}_2\text{O} \end{aligned}$$

\]

Determine the correct reaction phase

The splitting of water molecules (photolysis) occurs during the light-dependent reactions in the thylakoid membrane, releasing oxygen, electrons, and hydrogen ions (protons). Therefore, 6 water molecules must split during the light-dependent reactions to yield 12 hydrogen ions.
</reasoning>

<answer>
<mcq-option>other sugar molecules reacting with oxygen in the chloroplast</mcq-option>
<mcq-option>12 water molecules splitting apart during the light-independent reactions</mcq-option>
<mcq-correct>6 water molecules splitting apart during the light-dependent reactions</mcq-correct>
<mcq-option>12 water molecules splitting apart during the light-dependent reactions</mcq-option>
</answer>

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Answer:

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<reasoning>

Identify the source of hydrogen ions

Using the Photosynthesis Reactions knowledge point
\[
2\text{H}_2\text{O}
ightarrow 4\text{H}^+ + 4e^- + \text{O}_2
\]

Calculate the required water molecules

Using the Light-Dependent Reactions knowledge point
\[

$$\begin{aligned} &\text{Ratio: } \frac{2\text{ H}_2\text{O}}{4\text{ H}^+} = \frac{1\text{ H}_2\text{O}}{2\text{ H}^+}\\ &x\text{ H}_2\text{O} = 12\text{ H}^+ \times \frac{1\text{ H}_2\text{O}}{2\text{ H}^+} = 6\text{ H}_2\text{O} \end{aligned}$$

\]

Determine the correct reaction phase

The splitting of water molecules (photolysis) occurs during the light-dependent reactions in the thylakoid membrane, releasing oxygen, electrons, and hydrogen ions (protons). Therefore, 6 water molecules must split during the light-dependent reactions to yield 12 hydrogen ions.
</reasoning>

<answer>
<mcq-option>other sugar molecules reacting with oxygen in the chloroplast</mcq-option>
<mcq-option>12 water molecules splitting apart during the light-independent reactions</mcq-option>
<mcq-correct>6 water molecules splitting apart during the light-dependent reactions</mcq-correct>
<mcq-option>12 water molecules splitting apart during the light-dependent reactions</mcq-option>
</answer>

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