🌞 光合作用：植物把阳光做成饭🌞 Photosynthesis: Cooking with Sunlight
上一片讲酶——细胞里的化学反应都靠它提速。这一片看地球上最大的一场“做饭”：植物用阳光、水和二氧化碳做出糖，还顺手送出氧气。🦠 小细胞带你进厂参观。Last leaf was about enzymes — the accelerators behind every reaction in a cell. This leaf is about the planet's biggest kitchen: plants use sunlight, water and CO₂ to cook sugar — and give off oxygen while they're at it. 🦠 Little Cell takes you on a factory tour.
第 1 步：叶绿体，太阳能食品厂Step 1: The chloroplast, a solar food factory
原料从哪来，产品又是什么？Where do the ingredients come from — and what comes out?
阳光照进叶片，根吸来的水、气孔吸进的二氧化碳一起送上流水线，出来的产品是甜甜的葡萄糖，废气是氧气——对人来说却是宝贝。这座工厂叫叶绿体，绿色来自里面的叶绿素，它专门负责“抓光”。配方一句话：二氧化碳 + 水 —(光·叶绿体)→ 葡萄糖 + 氧气。Sunlight streams into the leaf; water from the roots and carbon dioxide from the air ride the same conveyor line. The product is sweet glucose, and the “exhaust” is oxygen — which for us is treasure. This factory is the chloroplast; its green colour comes from chlorophyll, the molecule that catches light. The recipe in one line: CO₂ + water —(light · chloroplast)→ glucose + oxygen.
这么长一条流水线，是一口气干完的吗？Is such a long line done in one single pass?
第 2 步：两个工段：抓光 + 拼糖Step 2: Two work zones: catch light + build sugar
流水线分两个工段。光反应工段：叶绿素抓住阳光，把水拆开，放出氧气，还造出小小的“能量电池”。暗反应工段：不直接需要光，拿着能量电池把二氧化碳一块块拼成葡萄糖。怎么证明真的放氧？把水草扣在漏斗下放到阳光下，会不停冒气泡；收集起来能让快熄灭的火柴复燃——那就是氧气。The line has two zones. The light reactions: chlorophyll catches sunlight, splits water, releases oxygen and charges little “energy batteries”. The dark reactions: they don't need light directly — they spend those batteries to snap CO₂ building blocks together into glucose. Proof that oxygen really comes out? Put pondweed under a funnel in sunlight and bubbles rise non-stop; collected, they make a fading match flare up again — that's oxygen.
那地球上这么多氧气，都是谁造出来的？So who makes all the oxygen on Earth?
第 3 步：地球氧气从哪来Step 3: Where Earth's oxygen comes from
陆地森林和大草原贡献一部分，但更大的头在海洋：数不清的浮游植物（藻类等）像一片看不见的森林，源源不断地产氧。它们和陆地植物一起，撑起了我们能呼吸的空气。所以保护森林、保护海洋，就是在保护地球的“氧气工厂”。Forests and grasslands chip in, but the bigger share comes from the ocean: countless phytoplankton (algae and friends) form an invisible forest that keeps pumping out oxygen. Together with land plants, they keep the air breathable. Protecting forests and oceans means protecting Earth's “oxygen factories”.
🎮 你来当工厂主管（30 秒）🎮 Your turn: factory manager (30 seconds)
道理讲完了。拖动光照和 CO₂ 滑块，看葡萄糖和氧气的产量表怎么变；再完成 4 张生产单。Theory done. Drag the light and CO₂ sliders to watch the glucose/oxygen output table — then finish 4 production orders.
一句话记住它：光合作用 = 叶绿体把光能装进葡萄糖，同时放出氧气；光照和 CO₂ 缺谁都不行。Remember it in one line: photosynthesis packs light energy into glucose and releases oxygen — and it stalls if either light or CO₂ runs short.
原料：水和二氧化碳；产品：葡萄糖 + 氧气；场所：叶绿体（叶绿素抓光）Ingredients: water and CO₂; products: glucose + oxygen; site: the chloroplast (chlorophyll catches light)光反应拆水放氧、充好能量电池；暗反应用它把 CO₂ 拼成葡萄糖Light reactions split water, release oxygen and charge the batteries; dark reactions spend them to build glucose地球氧气来自森林和海洋浮游植物；夜里没光，光合就停工Earth's oxygen comes from forests and ocean phytoplankton; with no light at night, photosynthesis stops
内容参考 OpenStax 等公开教材，多来源核对 · AI 生成、人工审核 · 发现错误欢迎指正，帮这片叶子长得更好。Based on OpenStax and other open textbooks, cross-checked across sources · AI-generated, human-reviewed · Spotted a mistake? Tell us — help this leaf grow.
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