要点 酶是生物催化剂，能通过降低反应的活化能加快反应速度，但不改变反应的平衡点。绝大多数酶的化学本质是蛋白质，具有催化效率高、专一性强、作用条件温和等特点。
equilibrium［ˌi:kwi'libriəm］n. 平衡，均衡；平静
例句 1. Mature natural environments are usually in equilibrium. 成熟的自然环境通常都是有均衡性的。
2. The rate of movement might be very slow: in the Indus plain, the movement of saline ground waters has still not reached equilibrium. 运动的频率可能非常缓慢：在印度河平原，含盐地下水的运动尚未达到平衡。
extend［ik'stend］v. 延长，延伸；舒展
例句 1. Offshore drilling platforms extend the search for oil to the ocean's continental shelves — those gently sloping submarine regions at the edges of the continents. 海底钻探平台延伸到海洋大陆架去寻找石油——即大陆边缘缓慢倾斜的海底区域。
2. It extends the scientist's thinking over the known facts. 这超越了科学家对已知事实的理解。
fluid［'flu:id］n. 液体，流体 a. 流动的
例句 1. Fluids in the lungs of the fetus keep yawning from occurring which disproves the developmental theory of yawning. 胎儿肺部的液体阻止了哈欠，这反驳了哈欠的发展理论。
2. The lungs of a fetus secrete a liquid that mixes with its mother's amniotic fluid. 胎儿的肺分泌出一种液体，和母体的羊水混合。
3. There's some kind of fluid with a strong smell on the balcony floor. 阳台的地板上有一种气味很浓的液体。
要点 注意区别：fluid主要指具有流动性的液体，而liquid指的就是液体。
fracture［'frækʧər］n./v.（使）断裂
例句 Fracture on tools also shows that a majority of ancient people were right-handed. 工具上的破裂处也表明古时大部分人都用右手。
frontal［'frʌntl］n. 额骨；额部 a. 正面的；前额的；锋面的
例句 1. Maturation of the frontal lobes of the brain is important for the long-term memory of motor activities instead of verbal descriptions. 成熟的大脑额叶对肌动活动而不是口头描述的长期记忆十分重要。
2. Frontal lobe function of the brain may need to develop before memory retrieval can occur. 大脑的额叶功能也许需要在找回记忆之前就发展好。
同义 anterior（a. 前面的）
gender［'ʤendər］n. 性别；（语法中的）性
搭配 gender differences 性别差异
例句 Gender inequality in pastoral societies is comparatively mild because wealth is relatively evenly distributed and women also learn the same skills as men do. 在田园社会性别不平等的情况相对缓和，因为财富分配相对均衡，而且女人可以学习和男人一样的技能。
gene［ʤi:n］n. 基因
例句 Gene therapy involves the process of inserting copies of a normal allele into the chromosomes of an individual who carries a faulty allele. 基因治疗需要将一个正常的等位基因嵌入到携带有缺陷的等位基因的患者的染色体中。
genetic［ʤə'netik］a. 基因的，遗传（学）的
搭配 genetic code 遗传密码；genetic engineering 遗传工程（学）
例句 1. In Texas, a lot of attention is being paid to genetic engineering because it is there that the most critical situation exists. 在德克萨斯州，遗传工程受到了广泛的关注，因为那是一些重要情况发生的领域。
2. What type of amber is probably the most valuable for genetic research? 哪种类型的琥珀可能对基因研究最有价值？
handedness［'hændidnis］n. 用右手或左手的习惯
例句 From the 158 stencils in the French cave of Gargas, we know that right-handedness was heavily predominant. 从法国加尔加斯洞穴中的158个模型可以知道，习惯使用右手的人占大多数。
hemisphere［'hemisfir］n.（天体的）半球；大脑半球
例句 1. The study showed that the individual had a left hemisphere slightly bigger than the right, and the same was found in another group of people. 该研究显示，这一个体的左脑半球相对于右脑更大，同样的现象在另一组人当中也有发现。
2. Detractors argue that geological forces depressed the activity of the northern hemisphere of Mars, therefore the terraces could not be formed by water. 反对者争论到地质力量削弱了火星北半球的活动性，因此阶地不可能是由水形成的。
hormone［'hɔ:rmoun］n. 激素；荷尔蒙
例句 1. Normally, the constantly changing levels of an animal's activity, for example sleeping, feeding, moving, reproducing, metabolizing, and producing enzymes and hormones, are well coordinated with environmental rhythms. 通常，动物不断变化的活动水平——比如睡觉、喂食、移动、繁殖、新陈代谢以及酶和荷尔蒙的产生都与环境的节奏相协调。
2. The short child of tall parents very likely had a hormone deficiency early in life. 高个子父母的孩子如果身材矮小，很有可能是小时候缺乏荷尔蒙。
要点 荷尔蒙源于希腊文，就是“激素”，是人体内分泌系统调节生理平衡的激素总称。
immune［i'mju:n］a. 免疫的，有免疫力的；不受影响的
搭配 immune system 免疫系统
例句 1. In vertebrates, the immune system supplies a multiple defense against internal parasites. 脊椎动物的免疫系统提供多重防御，来抵抗内部的寄生虫。
2. They were immune to drought. 他们未受旱灾影响。
要点 immune表示描述的事物不受其他事物的影响，例如：The surviving rabbits were increasingly immune to the virus. 幸存的兔子对病毒越来越具有免疫力。
impediment［im'pedimənt］n. 妨碍，阻碍（物）；身体上的某类残疾
例句 In densely-wooded environments, sound is the best means of communication over distance because it passes with little impediment from trees and other vegetation in comparison with light. 在茂密的树林环境中，声音是最好的远距离通信方式，因为和光相比，它几乎可以无障碍地穿过树木和其他植被。
同义 obstacle（n. 障碍）
inactivity［ˌinæk'tivəti］n. 静止，休止状态；不活泼
例句 The frequency of yawning will increase during extended periods of inactivity. 如果持续保持不活动，打哈欠的频率就会增加。
同义 stillness（n. 静止）
indefinite［in'definət］a. 无限期的；不确定的，不明确的
例句 The winter population fluctuates around approximately 320,000 deer, which will yield about 65,000 of either sex and any age annually for an indefinite period. 冬季（鹿群的）数量在32万只左右波动，而在一段不明确的时期内，每年将产生大约65000只性别和年龄都不确定的鹿。
要点 indefinite出现时表示作者不确定的信息，阅读的时候一定要注意，例如：indefinite number“不确定的数量”。
infant［'infənt］n. 婴儿 a. 婴儿的；初期的
例句 New techniques about the study of infant perception have improved the accuracy with which researchers observe and quantify infant responses. 研究婴儿感知力的新技术提高了精准性，使研究人员可以观察并量化婴儿的反应。
要点 注意infant可以引申为“初期的”。在阅读中见到infant time/period可以按字面理解为“婴儿时期”，但在特定环境下可能意为“初期阶段”。
inhale［in'heil］v. 吸入，吸气
例句 When you inhale, you breathe in oxygen and a variation of other gases, and when you exhale, you breathe out carbon dioxide. 吸气时，你会吸入氧气和其他各种气体，而呼气时，你会呼出二氧化碳。
同义 inbreathe（v. 吸入）
instinct［'instiŋkt］n. 本能，直觉；天性
例句 1. The instinct always forces green turtles to return to the beach where they were hatched. 本能驱使绿海龟总是回到它们被孵化出来的海滩。
2. Of course, in trying to explain the Roman phenomenon, one would have to place great emphasis on this almost instinct for the territorial imperative. 当然，在尝试解释罗马现象时，人们必须十分重视这种几乎是与生俱来的占有领地的天性。
intact［in'tækt］a. 无损伤的；完整的
例句 1. Within the well-preserved Messel fossils are insects with iridescent exoskeletons, frogs with skin and blood vessels intact, and even entire small mammals with preserved fur and soft tissue. 在保存完好的曼塞尔化石内部是有着闪光外骨骼的昆虫，皮肤和血管完好无损的青蛙，甚至是皮毛和软组织都完整的小型哺乳动物。
2. The ice shelf had kept intact for centuries despite the weather. 尽管天气变化，历经了几个世纪，冰架依然完好无损。
同义 undamaged（a. 无损伤的；完整的）
intensity［in'tensəti］n. 强烈，剧烈；强度
例句 The actual level of heat-island intensity depends upon such factors as the physical layout, population density, and productive activities of a metropolis. 热岛效应的强度取决于诸如城市布局、人口密度，以及大都市的生产活动这类因素。
要点 通常intensity用来表示强度，强调程度之深，比如：the intensity of hunger“饥饿程度”。
irregular［i'regjələr］a. 不规则的，不整齐的；变化的
搭配 an irregular coast line 曲折的海岸线
例句 1. The amount of air exchanged is even lower in REM (Rapid Eye Movement) than NREM (Non-rapid Eye Movement), because breathing is more irregular in REM, with brief episodes of shallow breathing or absence of breathing. 空气交换量在快速眼动睡眠时期比在非快速眼动时期甚至还要低一些，因为在快速眼动时期的呼吸是不规律的，伴有短暂的浅呼吸甚至呼吸停止现象。
2. The constituents of Allende are the refractory inclusions: irregular white masses that tend to be larger than chondrules. 阿连德陨星的成分是耐火的杂质：比陨石球粒还要大的不规则白色物体。
irritant［'iritənt］n. 刺激物 a. 有刺激性的；引起发炎的
例句 The irritant that caused the itching is very small, so it disturbs only a few nerve endings. 引起痒感的刺激物很小，因此只能使少数神经末梢产生感觉。
派生 irritation（n. 刺激）
lung［lʌŋ］n. 肺
例句 A complete diverse theory holds that yawning assists in the physical development of the lungs early in life, but has no biological function in adults. 一个完全不同的理论表明，打哈欠对于生命初期肺部的发育是有帮助的，但对于成年人来说并没有这种生理功能。
maturation［ˌmæʧu'reiʃn］n. 成熟；化脓
例句 The level of physiological maturation of the brain may support these types of memories but not the ones that explicit verbal descriptions were needed. 大脑的生理成熟程度或许可以支持这些类型的记忆，而不支持需要详细的口头描述的记忆。
同义 ripeness（n. 成熟）
metabolic［ˌmetə'bɑ:lik］a. 新陈代谢的
例句 1. The automatic, metabolic system may increase its dependence on air exchanges. 无意识的新陈代谢系统也许会增加其自身对气体交换的依赖。
2. Sea cucumbers have the ability to become quiescent and live at a low metabolic rate. 海参能够静止不动，并以很低的新陈代谢率生存。
metabolism［mə'tæbəlizəm］n. 新陈代谢，代谢（作用）
例句 Leatherbacks do not generate internal heat the way we do, or the way birds do, as a by-product of cellular metabolism. 棱皮龟产生内部热量的方式与我们和鸟类都不同，产热是它们细胞新陈代谢的副产品。
monitor［'mɑ:nitər］n. 显示器；监视器；班长 v. 监控
例句 1. Heart and respiration monitors supply the investigator with the number of heartbeats or breaths taken when a new stimulus is presented. 当一种新的刺激出现时，心脏和呼吸监视器可以给研究人员提供心跳或呼吸的数据。
2. Film analysis of the infant's responses, heart and respiration rate monitors, and sucking devices are used as effective tools in understanding infant perception. 婴儿反应的影像分析、心率和呼吸频率的监视器以及吮吸设备都是理解婴儿感知能力的有效工具。
muscle［'mʌsl］n. 肌肉；力量；实力
例句 When researchers measured the heart rate, muscle tension and skin conductance of people before, during and after yawning, they did notice some changes in skin conductance following yawning, indicating a slight increase in physiological activity. 研究人员测定了人在打哈欠之前、之中和之后的心跳、肌肉张力以及皮肤传导性，确实发现打哈欠时皮肤传导性会发生一些变化，这表明生理活动略有增加。
同义 brawn（n. 发达的肌肉）
narrow［'nærou］a. 狭窄的；勉强的 v.（使）变窄；（使）缩小
例句 1. Without this muscular action, inhaling is like sucking air out of a balloon and making the narrow passages tend to collapse. 如果没有这种肌肉活动，吸气就像从一个气球中向外吸气一样，会使狭窄的通道易于破裂。
2. With elevation increases, narrow and deep channels of water form throughout the marsh. 随着海拔升高，整个沼泽里就会形成窄而深的海峡。
要点 narrow除了可以形容空间的狭窄以外，还可以表示身体方面的狭窄，比如narrow shoulders“狭窄的肩部”。
neonate［'ni:ouneit］n. 初生儿
例句 Sophisticated techniques that have aided the discoveries in the neonate continue to be indirect. 对新生儿研究起到帮助作用的复杂技术仍然是间接措施。
nutrient［'nu:triənt］n. 滋养物，营养品 a. 滋养的，有营养的
例句 1. Some plants are able to tolerate comparatively low levels of certain minerals, but such plants are of little use for recycling nutrients back into depleted soils. 一些植物在某些矿物质水平相对较低的情况下可以存活，但这类植物几乎不能把营养物再循环到贫瘠的土地中去。
2. Much of the research on nutrient deficiencies is grounded on growing plants hydroponically. 大部分关于营养不足的研究都是基于用营养液培植的植物。
同义 nourishment（n. 营养品）
olfactory［oul'fæktəri］a. 嗅觉的
例句 His olfactory nerves were damaged by the poisonous gas. 他的嗅觉神经被毒气破坏了。
parasite［'pærəsait］n. 食客；寄生虫
例句 The tachinid fly is a parasite of harmful insects. 寄蝇是一种有害昆虫的寄生物。
periodic［ˌpiri'ɑ:dik］a. 周期的，定期的
例句 1. In some places, the water table is declining at a rate of a meter a year, necessitating the periodic deepening of wells and the use of ever-more-powerful pumps. 在某些地区，水位以每年1米的速度下降，使水井不得不建得越来越深，还要使用更强有力的泵。
2. This periodic extinction might be due to intersection of the Earth's orbit with a cloud of comets. 这种周期性灭绝可能是因为地球轨道和彗星云的交叉造成的。
同义 regular（a. 定期的）
rear［rir］n. 后部；臀部 v. 抚养 a. 后部的
例句 1. By moving the rear parts of their bodies up and down, modern whales swim in a different way from the way Ambulocetus swam. 现代鲸鱼通过身体后部的上下摆动来游泳，这有别于古陆行鲸游泳的方式。
2. They developed a technique for feeding the larvae and rearing them to spat. 他们研究出一种喂养幼虫并将其养成蚝卵的技术。
resistance［ri'zistəns］n. 反抗；抵抗力；阻力
例句 Parasitic relationships contain the interplay of aggression by the parasite and resistance and adaptation by the host. 寄生关系包括寄生虫之间的相互攻击和抵抗以及对寄主的适应。
respiration［ˌrespə'reiʃn］n. 呼吸
例句 This machine measures biomedical data, for example heart rate and respiration, and alerts the doctors if the patient's condition worsens. 这台机器测量诸如心率和呼吸的生物医学数据，而且当病人的情况恶化时，它会向医生发出警报。
respiratory［'respərətɔ:ri］a. 呼吸的，呼吸用的
例句 1. Other respiratory regulating mechanisms apparently cease functioning during sleep. 睡觉时，其他呼吸调节机制显然会停止工作。
2. Not only are there differences in the level of the functioning of respiratory systems, there are even changes in how they function. 不仅呼吸系统的运作水平存在差异，甚至连它们运转的方式都发生了变化。
rib［rib］n. 肋骨；翅脉；（叶）脉
例句 During sleep, movements of the rib cage for breathing are reduced, making the contractions of the diaphragm more important. 睡觉时，呼吸引起的胸腔运动会减少，这使隔膜的收缩作用更显重要。
shallow［'ʃælou］a. 浅的；浅薄的
例句 The conventional theory states when people are bored or sleepy, they often experience a drop in blood oxygen levels as a result of their shallow breathing. 传统的理论表明，当人感到无聊或有困意时，他们的血氧水平会下降，而这是由于他们的浅呼吸造成的。
同义 superficial（a. 浅的）
skeleton［'skelitn］n. 梗概；骨架；框架
例句 The skeleton of a warrior, buried 2,000 years ago and excavated last month, had multiple healed fractures to the skull, the left arm, and the ribs. 这具于2000年前埋葬、上个月被挖掘出来的武士的骨架上有多处被治愈的骨折痕迹，包括头骨、左臂和肋骨。
同义 sketch（n. 梗概）；framework（n. 框架）
要点 skeleton不仅可以表示人或动物的骨架，还可以表示事物的梗概或框架。
skull［skʌl］n. 颅骨；头脑
例句 The fossil consists of a complete skull of a Pakicetus, which is an extinct ancestor of modern cetaceans. 化石包含巴基鲸的完整头骨，它是现代鲸目动物已经灭绝的祖先。
spine［spain］n. 脊椎；（动植物的）刺；中心
例句 Vertebral column, or commonly called the backbone or spine, is named for its spinous processes. 脊柱，或者通常所说的脊椎，是由于它的棘突而得名的。
stimulus［'stimjələs］n.［pl. stimuli］刺激（物），激励
搭配 sensory stimulus 感官刺激；stimulus to 促进…，刺激…
例句 An animal's response to a stimulus is coordinated by their central nervous system, which gathers information about, and responds to, changes in the environment. 动物对刺激的反应是通过它们的中央神经系统的协调而完成的，中央神经系统会收集与环境变化相关的信息，并对这些变化作出回应。
strain［strein］n. 拉力；扭伤；菌株 v. 扭伤；使紧张；拉紧
搭配 strain one's shoulder 扭伤肩膀
例句 1. The deadliest strains of the virus perished with their hosts simultaneously as natural selection favored strains that could infect hosts but not kill them. 最致命的毒株与它的寄主一同死亡，因为自然选择更偏向那些能使寄主感染，而不是杀死寄主的菌株。
2. Genetic engineering also may supply a partial solution, as new strains of drought-resistant crops continue to be developed. 随着抗旱作物的新品种被继续培养，遗传工程也许会提供一个不完全的解决方案。
同义 sprain（n./v. 扭伤）
suppress［sə'pres］v. 抑制，阻止
例句 1. If the theory was correct, breathing air with extra carbon dioxide should have triggered yawning, while breathing pure oxygen should have suppressed yawning. 如果这个理论是正确的，那么，吸入二氧化碳过多的空气应该引起哈欠，而吸入纯氧则能抑制哈欠。
2. The high costs of converting to sound and the early limitations of sound technology were among the factors that suppressed innovations or retarded advancement in these other areas. 转换声音的高成本和早期声音技术的局限性是抑制创新或延缓其在其他领域发展的因素。
同义 restrain（v. 抑制）
symptom［'simptəm］n. 症状；征兆
例句 1. Mineral deficiencies often can be detected by specific symptoms. 矿物质缺乏经常能通过特殊的症状被发现。
2. Much of the focus of the lecture was on the recognition of vitamin deficiency symptoms. 这场讲座的大部分重点是识别缺乏维生素的症状。
同义 sign（n. 征兆）
synchronization［ˌsiŋkrənə'zeiʃn］n. 同步，同时性
例句 In spite of the fact that the external cue has synchronization with the period of the internal cycle, the animal's timer itself continues to have its own genetically built-in period close to 24 hours. 尽管这些外部信号与动物自身的生命周期具有同步性，动物本身的生物钟也会维持一个由基因决定的生物周期，这个周期接近24小时。
toddler［'tɑ:dlər］n. 学步的小孩
例句 Physiological immaturity may be part of why infants and toddlers do not form extremely enduring memories, even when they hear stories that promote such remembering in preschoolers. 心理不成熟也许是婴儿和学步孩童没能形成长期记忆的部分原因，就算当他们听到那些促进学龄前儿童记忆的故事时也是如此。
traumatic［trau'mætik］a. 创伤的；痛苦的，不愉快的
