📚 Year 11 OCR Science: Core Knowledge Organiser | Year 11 OCR 科学：核心知识点梳理
Mastering the Year 11 OCR Science curriculum means connecting the big ideas across Biology, Chemistry and Physics. This organiser covers the essential knowledge you need, from cells and inheritance to atomic structure, chemical reactions, forces and electricity. Each section is designed to help you focus on key concepts and recall them with confidence.
掌握 Year 11 OCR 科学课程意味着将生物学、化学和物理学中的核心概念联系起来。本知识梳理涵盖你需要的关键知识，从细胞与遗传到原子结构、化学反应、力与电。每一节都旨在帮助你聚焦核心概念，自信地进行知识回顾。
1. Cell Structure and Specialisation | 细胞结构与特化
All living organisms are built from cells. Eukaryotic cells, such as those in animals and plants, contain a nucleus, cytoplasm, cell membrane, mitochondria and ribosomes. Plant cells also have a rigid cell wall, a permanent vacuole and chloroplasts for photosynthesis. Prokaryotic cells, like bacteria, are much smaller and lack a nucleus; their DNA floats freely in the cytoplasm as a single loop and they may carry extra plasmids.
所有生物体都由细胞构成。真核细胞，例如动物和植物细胞，含有细胞核、细胞质、细胞膜、线粒体和核糖体。植物细胞还拥有坚硬的细胞壁、一个中央大液泡以及进行光合作用的叶绿体。原核细胞，例如细菌，要小得多，没有细胞核；它们的 DNA 以单环形式游离在细胞质中，并可能携带有额外的质粒。
Specialised cells are adapted to perform specific functions. Sperm cells have a long tail and many mitochondria for movement; root hair cells increase surface area for water absorption; xylem vessels are hollow tubes reinforced with lignin to transport water and support the plant.
特化细胞能够适应并执行特定功能。精细胞拥有长长的尾巴和大量线粒体以供运动；根毛细胞增大表面积以吸收水分；木质部导管是空心管状结构，由木质素加固，用于运输水分并支撑植物。
2. Enzymes and Digestion | 酶与消化
Enzymes are biological catalysts that speed up metabolic reactions without being used up. They have an active site with a specific shape, allowing only a particular substrate to bind – the lock and key model. Enzyme activity is affected by temperature and pH; extreme conditions can denature the enzyme, permanently changing the shape of the active site.
酶是生物催化剂，能够加速代谢反应而自身不被消耗。酶分子上有一个形状特定的活性位点，只允许特定的底物结合——这就是锁钥模型。酶的活性受温度和 pH 的影响；极端条件会使酶变性，永久地改变活性位点的形状。
During digestion, large insoluble molecules are broken down into smaller soluble ones. Carbohydrases such as amylase break down starch into sugars; proteases break down proteins into amino acids; lipases break down lipids into glycerol and fatty acids. Bile, produced by the liver, neutralises stomach acid and emulsifies fats to provide a larger surface area for lipase action.
在消化过程中，大分子不溶性物质被分解为较小的可溶性物质。碳水化合物酶如淀粉酶将淀粉分解为糖；蛋白酶将蛋白质分解为氨基酸；脂肪酶将脂类分解为甘油和脂肪酸。由肝脏产生的胆汁能够中和胃酸并乳化脂肪，为脂肪酶的作用提供更大的表面积。
3. The Circulatory System | 循环系统
The human circulatory system consists of the heart, blood vessels and blood. The heart is a double pump: the right side pumps deoxygenated blood to the lungs, while the left side pumps oxygenated blood around the body. Valves prevent backflow of blood. Arteries carry blood away from the heart under high pressure and have thick, muscular walls. Veins return blood to the heart and contain valves. Capillaries are extremely thin, allowing efficient diffusion of gases and nutrients.
人体循环系统由心脏、血管和血液组成。心脏是一个双泵：右侧将缺氧血泵入肺部，左侧将含氧血泵送到全身。瓣膜能够防止血液倒流。动脉将血液在高压下带离心脏，管壁厚且肌肉发达。静脉将血液送回心脏，内部含有瓣膜。毛细血管极薄，能够高效地进行气体和营养物质的扩散。
Blood is composed of plasma, red blood cells, white blood cells and platelets. Red blood cells contain haemoglobin, which binds to oxygen in the lungs and releases it in tissues. White blood cells defend against pathogens, while platelets help blood clot to prevent excessive bleeding.
血液由血浆、红细胞、白细胞和血小板组成。红细胞含有血红蛋白，能在肺部与氧气结合，并在组织处释放氧气。白细胞负责抵抗病原体，血小板则帮助血液凝固，防止过度出血。
4. Genetic Inheritance | 遗传与变异
DNA is a polymer made of two twisted strands forming a double helix. A gene is a small section of DNA that codes for a particular sequence of amino acids to build a specific protein. The entire set of genetic material in an organism is called the genome. Understanding the human genome helps scientists identify genes linked to diseases and develop new treatments.
DNA 是由两条缠绕的链组成的双螺旋聚合物。基因是 DNA 上的一小段，编码特定的氨基酸序列以构建特定的蛋白质。生物体的整套遗传物质称为基因组。了解人类基因组有助于科学家识别与疾病相关的基因并开发新的治疗方法。
During sexual reproduction, alleles from both parents combine. Some alleles are dominant and others recessive. A Punnett square can be used to predict the probability of offspring inheriting certain traits. In monohybrid inheritance, if both parents are heterozygous for a trait (Aa), the offspring have a 75% chance of showing the dominant characteristic and a 25% chance of showing the recessive characteristic.
在有性生殖过程中，来自父母双方的等位基因组合在一起。一些等位基因是显性的，另一些是隐性的。旁纳特方格可用于预测后代继承某一性状的概率。在单基因遗传中，如果双亲均为杂合子 (Aa)，后代表现出显性性状的概率为 75%，表现出隐性性状的概率为 25%。
5. Atomic Structure and Bonding | 原子结构与化学键
Atoms contain a tiny central nucleus made of protons and neutrons, surrounded by electrons orbiting in shells. The atomic number identifies an element by its number of protons, while the mass number is the total of protons and neutrons. Isotopes are atoms of the same element with different numbers of neutrons. Ions form when atoms gain or lose electrons to achieve a full outer shell.
原子包含一个由质子和中子构成的微小中心核，核外电子在电子层上绕核运动。原子序数通过质子数来确定元素种类，质量数则是质子数与中子数的总和。同位素是质子数相同但中子数不同的同种元素的原子。当原子得到或失去电子以达到稳定的最外层时，就会形成离子。
Ionic bonding occurs between metals and non‑metals, where electrons are transferred creating oppositely charged ions held by strong electrostatic forces. Covalent bonding involves the sharing of pairs of electrons between non‑metal atoms. Metallic bonding features a sea of delocalised electrons surrounding positive metal ions, giving metals their characteristic conductivity and malleability.
离子键发生在金属与非金属之间，电子发生转移，形成被强大静电力维系的正负离子。共价键涉及非金属原子之间共用电子对。金属键的特征是离域电子海包围着带正电的金属离子，这赋予了金属特有的导电性和延展性。
6. The Mole and Quantitative Chemistry | 摩尔与定量化学
n grams is equal to its relative formula mass Mᵣ. This allows chemists to calculate reacting masses: mass = moles × Mᵣ. Conservation of mass means the total mass of products equals the total mass of reactants in a closed system.
摩尔是物质的量的单位。一摩尔物质精确含有 6.02 × 10²³ 个粒子（阿伏伽德罗常数）。一摩尔物质的质量（以克为单位）等于其相对式量 Mᵣ。这使得化学家能够计算反应质量：质量 = 摩尔数 × Mᵣ。质量守恒定律表明，在封闭体系中，产物的总质量等于反应物的总质量。
is essential for titration calculations. Atom economy evaluates how much of the reactants end up in the desired product, while percentage yield compares the actual mass obtained to the theoretical maximum.
溶液的浓度以 g/dm³ 或 mol/dm³ 计量。等式 摩尔数 = 浓度 × 体积（以 dm³ 计）对于滴定计算至关重要。原子经济性评估有多少反应物最终进入了目标产物，而产率百分比则比较实际获得的质量与理论最大产量。
7. Energy Changes in Reactions | 反应中的能量变化
Exothermic reactions transfer energy from the reacting chemicals to the surroundings, causing a temperature rise. Examples include combustion, neutralisation and respiration. Endothermic reactions absorb energy from the surroundings, resulting in a temperature drop. Thermal decomposition and the reaction of citric acid with sodium hydrogencarbonate are endothermic.
放热反应将能量从反应物转移至周围环境，导致温度升高。例子包括燃烧、中和反应和呼吸作用。吸热反应从周围环境中吸收能量，导致温度下降。热分解以及柠檬酸与碳酸氢钠的反应都是吸热反应。
ulated using bond energies: ΔH = total energy to break bonds − total energy released when bonds form. Reaction profile diagrams show the activation energy barrier and whether the reaction is exothermic or endothermic.
断键需要吸收能量（吸热），成键则会释放能量（放热）。反应的总能量变化可以利用键能计算：ΔH = 断裂所有键所需的总能量 − 成键所释放的总能量。反应历程图展示了活化能势垒，并标明反应是放热还是吸热。
8. Motion and Forces | 运动与力
n. Velocity is speed in a given direction. Acceleration is the rate of change of velocity: a = (v − u) / t. On a distance– ing line indicates constant speed, while a horizontal line means the object is stationary.
标量，如速度和距离，只有大小。矢量，如速率和力，既有大小也有方向。速率是给定方向上的速度。加速度是速度的变化率：a = (v − u) / t。在距离–时间图中，一条倾斜的直线表示匀速运动，水平线则表示物体处于静止状态。
nks force, mass and acceleration: F = m × a. The third law states that for every action there is an equal and opposite reaction. Stopping distance is the sum of thinking distance and braking distance, and is affected by speed, alcohol, drugs and road conditions.
牛顿第一定律指出，若无合力作用，物体将保持静止或匀速直线运动状态。牛顿第二定律将力、质量和加速度联系在一起：F = m × a。第三定律指出，每一个作用力都有一个大小相等、方向相反的反作用力。制动距离是反应距离与刹车距离的总和，受速度、酒精、药物以及路况的影响。
9. Electric Circuits | 电路
red across a component and drives the current through it. Resistance opposes the flow of current: V = I × R. In series circuits, current is the same through all components and the total resistance is the sum of individual resistances. In parallel circuits, the current splits across branches while the potential difference is the same across each branch.
电流是电荷流动的速率。在单一闭合回路中，各处电流相等。电势差（电压）是在元件两端测量的，驱动电流通过该元件。电阻会阻碍电流的流动：V = I × R。在串联电路中，通过所有元件的电流相同，总电阻等于各电阻之和。在并联电路中，电流在各支路中分流，而各支路两端的电势差相同。
Components such as thermistors and LDRs (light‑dependent resistors) change their resistance with temperature and light. In a thermistor, resistance decreases as temperature rises; in an LDR, resistance falls as light intensity increases. These properties make them useful in sensor circuits for automatic night lights and thermostats.
热敏电阻和光敏电阻 (LDR) 等元件的电阻会随温度和光照发生变化。热敏电阻的电阻随温度升高而降低；光敏电阻的电阻随光照强度增大而减小。这些特性使它们在自动夜灯和恒温器等传感器电路中非常有用。
10. Waves and Radiation | 波与辐射
amples include electromagnetic waves and water ripples. In longitudinal waves, oscillations are parallel to the direction of energy transfer, like sound waves. The wave equation is v = f × λ, where v is wave speed, f is frequency and λ is wavelength.
波传递能量而不传递物质。在横波中，振动方向与能量传递方向垂直；例子包括电磁波和水波纹。在纵波中，振动方向与能量传递方向平行，例如声波。波动方程为 v = f × λ，其中 v 表示波速，f 表示频率，λ 表示波长。
The electromagnetic spectrum is a continuous family of transverse waves, all travelling at the same speed in a vacuum. In order of decreasing wavelength and increasing frequency: radio waves, microwaves, infrared, visible light, ultraviolet, X‑rays and gamma rays. Each region has distinct uses and hazards; for example, ultraviolet can ionise skin cells, and X‑rays can penetrate soft tissues but are absorbed by bone.
电磁波谱是一组连续的横波家族，所有波在真空中都以相同的速度传播。按照波长递减、频率递增的顺序排列：无线电波、微波、红外线、可见光、紫外线、X 射线和伽马射线。每个波段都有独特的用途和危害；例如，紫外线可使皮肤细胞电离，X 射线能穿透软组织但被骨骼吸收。
Radioactive decay is entirely random and occurs when an unstable nucleus emits ionising radiation. Alpha particles (helium nuclei) are highly ionising but weakly penetrating; beta particles (high‑speed electrons) are moderately ionising and penetrating; gamma rays are electromagnetic waves with low ionisation power but very high penetration. Half‑life is the time for half the nuclei in a sample to decay.
放射性衰变是完全随机的，发生于不稳定原子核放射出电离辐射之时。α 粒子（氦原子核）电离能力强，但穿透力弱；β 粒子（高速电子）电离能力和穿透力均中等；γ 射线是电离能力弱但穿透力极高的电磁波。半衰期是指样品中一半原子核发生衰变所需的时间。
Published by TutorHao | 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