📚 GCSE WJEC Science: High-Frequency Topics Summary | GCSE WJEC 科学：高频考点总结
This article summarises the most frequently examined topics in the GCSE WJEC Science (Double Award) specification. Covering Biology, Chemistry, and Physics, we highlight core concepts, key equations, and common question types to help you focus your revision effectively.
本文总结了 GCSE WJEC 科学（双奖）大纲中最高频的考点。涵盖生物、化学和物理，我们突出核心概念、关键方程和常见题型，帮助你高效复习。
1. Cell Structure & Microscopy | 细胞结构与显微镜
Plant cells possess a rigid cell wall, a large permanent vacuole, and chloroplasts for photosynthesis, all of which are absent in animal cells.
植物细胞具有坚硬的细胞壁、一个中央大液泡和进行光合作用的叶绿体，而这些结构在动物细胞中都不存在。
Eukaryotic cells (e.g. plant and animal cells) contain a distinct nucleus, whereas prokaryotic cells (e.g. bacteria) lack a membrane-bound nucleus and have free-floating DNA.
真核细胞（如动植物细胞）具有明显的细胞核，而原核细胞（如细菌）没有膜包围的细胞核，DNA游离在细胞质中。
To find the magnification of a specimen, use the relationship between image size and actual size:
Magnification = Image size ÷ Actual size
计算放大倍数时，用图像大小除以实际大小：放大倍数 = 图像大小 ÷ 实际大小。
Movement of substances across membranes occurs by diffusion (passive, down a gradient), osmosis (water through a partially permeable membrane), and active transport (against a gradient, requiring energy).
物质穿过细胞膜的方式有扩散（被动顺浓度梯度）、渗透（水通过半透膜）和主动运输（逆浓度梯度并消耗能量）。
2. Digestion and Enzymes | 消化与酶
Enzymes are protein molecules that act as biological catalysts, each specific to a particular substrate, explained by the lock-and-key model.
酶是起生物催化剂作用的蛋白质分子，每种酶对特定底物具有专一性，这可以用锁钥模型解释。
Enzyme activity rises with temperature to an optimal point, beyond which the enzyme denatures; pH also has an optimum – for instance, pepsin works best in the acidic stomach at pH 2.
酶活性随温度升高达到最适点后变性失活；pH 也有最适值，例如胃蛋白酶在胃中的酸性环境 pH 2 时活性最高。
During digestion, carbohydrases (such as amylase) break starch into sugars, proteases into amino acids, and lipases into fatty acids and glycerol. Bile neutralises stomach acid and emulsifies fats.
消化过程中，淀粉酶将淀粉分解为糖，蛋白酶分解为氨基酸，脂肪酶分解为脂肪酸和甘油。胆汁能中和胃酸并乳化脂肪。
Standard food tests: iodine solution turns blue-black with starch; Benedict's solution gives a brick-red precipitate with reducing sugars when heated; Biuret reagent turns purple in the presence of protein.
标准食物检测：碘液遇淀粉变蓝黑色；本尼迪克特试剂与还原糖加热后变砖红色；双缩脲试剂遇蛋白质变紫色。
3. Photosynthesis and Plant Transport | 光合作用与植物运输
The overall word equation for photosynthesis is carbon dioxide + water → glucose + oxygen, using light energy trapped by chlorophyll.
光合作用的总文字方程式为：二氧化碳 + 水 → 葡萄糖 + 氧气，利用叶绿素捕获的光能。
6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂
6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂
The rate of photosynthesis is limited by light intensity, carbon dioxide concentration, and temperature; the factor in shortest supply determines the rate.
光合作用速率受光照强度、二氧化碳浓度和温度的限制；最缺乏的因素会成为限制因子。
In plants, xylem vessels transport water and dissolved minerals upwards from the roots, while phloem tubes carry sugars (translocation) from leaves to growing or storage tissues.
植物中，木质部导管将水和矿物质自根部向上运输，而韧皮部筛管将糖（有机物运输）从叶片运往生长或储存的组织。
Transpiration is the evaporation of water vapour from the leaf surface, creating a pull that draws water up through the plant; it is affected by light, temperature, wind and humidity.
蒸腾作用是水蒸气从叶片表面蒸发的过程，产生拉力使水向上运输；它受光照、温度、风和湿度的影响。
4. Atomic Structure and the Periodic Table | 原子结构与周期表
) arranged in shells. Atomic number = number of protons; mass number = protons + neutrons.
原子由含质子（+1）和中子（0）的原子核以及
Published by TutorHao | GCSE Science Revision Series | aleveler.com
更多咨询请联系16621398022（同微信）
或截图后用「扫一扫 → 相册」选择本图