---
title: "Light reactions of photosynthesis Template | MolDraw"
url: https://www.moldraw.com/templates/biopath-light-reactions/
description: "Light reactions of photosynthesis template: PSII (P680) with water splitting, plastoquinone, cytochrome b₆f (Q cycle), plastocyanin, PSI (P700), ferredoxin…"
lang: en
publisher: Scidart Academy
generated: 2026-10-28
---
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# Light reactions of photosynthesis template

![Light reactions of photosynthesis template: PSII (P680) with water splitting, plastoquinone, cytochrome b₆f (Q cycle), plastocyanin, PSI (P700), ferredoxin and FNR making NADPH; protons pumped into the lumen drive CF₀CF₁ ATP synthase. Plastoquinone/plastoquinol structures.](https://www.moldraw.com/templates/biopath-light-reactions.webp)

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PSII (P680) with water splitting, plastoquinone, cytochrome b₆f (Q cycle), plastocyanin, PSI (P700), ferredoxin and FNR making NADPH; protons pumped into the lumen drive CF₀CF₁ ATP synthase. Plastoquinone/plastoquinol structures.

## What the template shows

- Linear electron flow from water to NADP⁺ through two photosystems, coupled to ATP synthesis in the thylakoid
- Thylakoid membrane: the Z scheme laid flat
- Proton numbers per O₂ released (4 e⁻)
- Stroma · low [H⁺]
- thylakoid membrane
- NADP⁺ reductase
- ATP synthase
- ADP + Pᵢ → ATP
- Mn₄CaO₅ cluster
- NADP⁺ + H⁺ → NADPH
- Thylakoid lumen · high [H⁺]
- Plastoquinone is reduced at PSII and oxidised at cytochrome b₆f
- R = isoprenoid tail (9 isoprene units, PQ-9)
- plastoquinol (PQH₂)
- Electron path: H₂O → PSII → PQ → cyt b₆f → plastocyanin (PC) → PSI → ferredoxin (Fd) → FNR → NADPH.
- Per O₂: 2 H₂O split by the Mn₄CaO₅ cluster, 8 photons (4 at each photosystem), 2 NADPH, ≈ 12 H⁺ into the lumen and ≈ 3 ATP.
- Cyclic flow around PSI (Fd → cyt b₆f → PC) makes ATP but no NADPH, adjusting the ATP : NADPH ratio.
- The ATP and NADPH made here drive the Calvin cycle in the stroma.

Drawn with 22 atoms, 1 arrow, 69 shapes – every one editable in MolDraw.

## Sources

- [Nelson & Cox, Lehninger Principles of Biochemistry, 8th ed., 2021](https://openlibrary.org/isbn/9781319228002) Textbook
- [Berg, Tymoczko, Gatto & Stryer, Biochemistry, 9th ed., 2019](https://openlibrary.org/isbn/9781319114657) Textbook
- [Voet & Voet, Biochemistry, 4th ed., Wiley 2011](https://openlibrary.org/isbn/9780470570951) Textbook

## How to use this template

1. Press **Edit in MolDraw**. The template opens on the canvas of the free MolDraw editor.
2. Change anything: move structures, edit atoms and labels, recolour highlights or delete what you do not need.
3. Add your own structures, arrows and text next to it, or combine several templates on one page.
4. Export the drawing as PNG, SVG or PDF for slides, worksheets, theses and papers.

## Frequently asked questions

### Is the Light reactions of photosynthesis template free?

You can preview the Light reactions of photosynthesis template here and open and edit it in MolDraw for free. Downloading or exporting it is part of MolDraw Pro, together with the other premium templates.

### Can I edit the Light reactions of photosynthesis template?

Yes. It opens as an ordinary MolDraw drawing, so every structure, arrow, label and colour can be changed, and you can add your own content around it.

### Is the chemistry checked?

Every structure is checked with RDKit and every curly arrow passes MolDraw’s electron-flow audit. The sources used are listed on this page.

### Are the biochemical pathways drawn with structures?

Yes. Pathway templates show the intermediates as structures, with enzymes and cofactors (NAD⁺, FAD, ATP) on the arrows.

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