chap8 凝集素(2)
2025年湖南长沙青竹湖湘一外国语校中考冲刺(2)英语试题试卷含答案
2025年湖南长沙青竹湖湘一外国语校中考冲刺（2）英语试题试卷注意事项：1．答卷前，考生务必将自己的姓名、准考证号填写在答题卡上。
2．回答选择题时，选出每小题答案后，用铅笔把答题卡上对应题目的答案标号涂黑，如需改动，用橡皮擦干净后，再选涂其它答案标号。
回答非选择题时，将答案写在答题卡上，写在本试卷上无效。
3．考试结束后，将本试卷和答题卡一并交回。
Ⅰ. 单项选择1、–– He looks ________. What has happened to him?–– He thought he could get good grades in the test, but failed.A．upset B．happy C．excited2、Singing is a form of expression that can be understood by everyone. Also, some songs can cheer people up when they_______ in trouble.A．will be B．aren’t C．are3、Life is ________ /fʊl/ of happiness and pain. You never know what will happen next.A．fall B．fill C．feel D．full4、My brother moved to Korea with his family last year. I haven’t heard from him until now, which makes me worried about him.A．had contact with B．had a chat withC．telephoned D．received letters from5、I __________ to Canada twice. It’s so beautiful.A．won’t go B．have goneC．don’t go D．have been6、---Has Jim known the good news?--Not yet. I will tell him about it ________ he comes back.A．while B．until C．as soon as D．since7、— What did you see in the crime scene?— On a table pushed __________ a wall there were bottles of beer and wine.A．above B．across C．against D．around8、—Can you spare time to come to our Thanksgiving party?—Well, I don’t knowA．that I can finish my work by thenB．if can I finish the work by thenC．whether I can finish the work by then9、—Can I join you? —Sure , we are discussing ______.A．why we like the movie B．who should we go withC．how can we get there D．when shall we go for a picnic10、Most of us check our smart phones 47 times on an average(平均)day, and ______ double between the ages of 18 and 24.A．hardly B．nearly C．mostly D．widelyⅡ. 完形填空11、There was a time when Whitney didn't have a lot of friends. She was a bit shy and didn’t 1 much. She never really wanted to be popular, 2 she did want to have someone to share secrets and laughs with. All through high school, though, she didn't find a lot of 3 ．When it came time to go to college, Whitney was quite nervous. She was going to room with someone she didn't 4 and live in a town 300 miles away from home. There wouldn't be any person she knew in town. She had no idea 5 she was going to make friends in this new environment.The first week of classes, 6 happened and it changed Whitney's life forever. In her English Composition class, every student was 7 to share a little about herself. Whitney told everyone where she called home and all of 8 things that students share in such situations．The final question for each student was always the 9 ：“What is your goal for this class?”Now, most of the students said it was to get a good grade, pass the exam or something 10 that, but for some reasons, Whitney said something very different. She said that her goal was to make just one good 11 .While 12 of the students sat quietly, one student came to Whitney and held out her hand and introduced herself. The girl asked 13 she would be her friend. The whole room was silent--all eyes looked at Whitney and the hand extended (延伸的)just in front of her. She smiled and reached her hand out to take the girl’s hand and a friendship was formed. It was a friendship that 14 all through college and many years after that. It was a friendship that brought two people together. Whitney learned the power of asking for what she wanted, being 15 and taking actions.1．A．speak B．tell C．say D．talk2．A．but B．and C．so D．because3．A．friendship B．knowledge C．money D．happiness4．A．like B．want C．know D．tell5．A．how B．why C．when D．where6．A．nothing B．anything C．everything D．something7．A．asked B．taught C．warned D．ordered8．A．the other B．any other C．others D．the others9．A．different B．similar C．same D．difficult10．A．as B．with C．together D．like11．A．classmate B．friend C．sister D．brother12．A．most B．all C．every D．each13．A．when B．how C．why D．if14．A．lasted B．made C．broke D．had15．A．happy B．kind C．honest D．strongⅢ. 语法填空12、Millie :Have you heard about the pop star Nancy? It's said that she has got cancer.Sandy:I 1．(hear) about it last week. It's very sad because she 2．(be) so kind.Millie: I heard that Nancy once donated ~100,000 to people who 3．(suffer) great loss in the earthquake in Wenchuan. Sandy: Yes. She is a generous girl.Millie: Now Nancy 4．(receive) medical treatment in Belling. An operation5．(do) on her yesterday and it was a success.Sandy . That's great. I really hope Nancy 6．(get) well again soon.Ⅳ. 阅读理解A13、One morning Fan Xing discovered that her classroom had changed. The 13-year-old saw that the desks were no longer in rows(排), but pushed together to make six bigger desks.The new arrangement(排列) was part of a reform(改革) at Fan's school, Changsha Daotian Middle School in Hunan. About five weeks ago, more than 2,000 junior students at the school began studying in this way, with six to eight students sitting in groups."This reform is designed to provide students with easier ways to study and more chances for discussion,"said Liu Xu,na school head teacher. "Our school hopes it can improve students' abilities(能力) for self-study as well as teamwork."The new arrangement took some time for students to get used to."I was too curious(好奇) about it for the first two days," said Fan. But soon she and her classmates got used to it." Now our class is quieter because we can stop loud students with some simple gestures(手势),"said Fan. "What's more,we can express our own ideas and learn others' through discussion. It's a better way to study."Feng Yu likes this new classroom arrangement very much and has made some progress studying. The 14-year-old said, "Group members first discuss,and then explain the solutions or answers to difficult questions in front of the whole class.""The discussion gives us more confidence to make speeches,"said Feng."We can also improve our friendships."The reform has asked for more from teachers.They have no more than 15 minutes to teach in class."It is a big challenge to teach in such short time the lessons which should be taught in 45 minutes,"English teacher Wang Jing said."We have to improve methods to teach better. We must prepare some interesting topics and exercises before class so that students can discuss them."Wang said that some students always talk. The teachers have to move continuously in the classroom to keep them quiet and get them to concentrate on class."It demands more, but I believe it will pay off,"Wang added.1．From the first paragraph of the passage, we know________.A．Fan Xing was a 13-year-old studentB．Fan Xing's classroom was changed in rowsC．Fan Xing's desk was no longer in her classroom2．The purpose of the new classroom arrangement is to________.A．make the students feel fresh and interestedB．provide students with more chances for teamworkC．divide big classes into small classes3．How did the new classroom arrangement help the students' study according to the passage?A．By stopping loud students using simple gestures.B．By giving students more chances to work in groups.C．By making students explain difficult questions after school.4．What is the big challenge for the teachers in classroom teaching in the reform?A．The teachers have to improve their studying methods.B．The teachers must prepare more interesting topics for exercises.C．The teachers are only given 15 minutes to teach in one period(节) of the class.5．Which of the following is NOT true according to the passage?A．The students in Changsha Daotian Middle School are sitting in groups when having classes.B．The reform in the school is aimed at improving the students' abilities for self-study.C．Studying in groups gives the students more confidence to concentrate on class.B14、Students in western Ohio(俄亥俄州) have to say “bye-bye” to snow days. Snow may fall, but students won’t be able to spend the days sledding(滑雪橇). Classes will continue online. Officials say that holding electronic workdays(e-days) will help students keep up with their studies. It will also prevent requiring students to make up schooldays later in June.Which would you prefer: spending a cold day on a computer, or sitting in school in June when you should be on vacation? Jordan Dewar, a student reporter, holds the opinion that having online work on a snow day is the better choice. “You would be working on a day that you already planned on having schoolwork.”“Havi ng extra days of school in summer can interfere with(妨碍) families’ vacation plans. Besides, what if your school does not have air-conditioning? Imagine sweating through seven hours at school on a hot June day when you could have been relaxing by a pool wit h your family. Doesn’t an e-day sound better than that?” Jordan Dewar said.For some students, it would be easier to concentrate(专注) on e-days than on makeup days. “You can do a little workonline, go play, and then come back later,” says Rachel Meyers, 12. “But on June days you would just have to sit there for seven hours, thinking about how you could be outside, so you lose focus.”There are some students arguing that it’s not fair to ditch snow days, however. They say that snow days give them a much-needed break. They also note that missing a day here and there is not enough to put them behind. Most students in Silver Valley School think one problem of e-days is that sometimes siblings(兄弟姐妹们) have to share computers at home. In addition, it punishes the students who don’t have computers at home. When school starts again after e-days, these students will be left behind and have to work double-time to catch up with others.“School budget cuts(预算削减) across the country are expected to continue into the 2017-2018 school year.” the American Association of School Administrators(AASA) Web site states. “The school wouldn’t be able to afford both online classes and taking care of the school,” Austin Krewson, an eighth grader, says.Moreover, electricity is likely to be cut off during snowstorms. If kids don’t have power at home, the money and the time in running the new program would be wasted.1．What can we learn from Paragraph 1?A．Officials suggest students should have more schooldays in June.B．Officials believe snow days put students behind in their studies.C．Students have to end snow days earlier than planned.D．Students won’t have sleddin g classes at school.2．The student reporter, Jordan Dewar, believes that _____.A．siblings can help each other with their studies on e-daysB．students can learn better on e-days than on makeup daysC．having e-days in winter will save the cost of air-conditioningD．students should study online when it snows heavily on weekdays3．What does the word “ditch” in Paragraph 5 probably mean?A．give up B．put off C．carry out D．pay for4．The writer mentions the statements on the AASA Web site to _____.A．explain the reason to hold the e-day programB．show the difficulty of running the e-day programC．suggest government should spend more money on educationD．stress why some students can’t afford computers for online classesC15、No Car Day was first started by 34 cities in France on September 22, 1998. It was started to protect the environment. Bynow, more than 1,000 cities around the world have had a No Car Day.The first No Car Day in China was in Chengdu in 2001. Other cities including Taipei, Shanghai and Wuhan, also support the day.In Beijing, more and more people are taking part in the activity. It asks drivers to leave their cars at home for one day each month and walk or ride a bike to work. It also calls on Beijingers not to use cars on June 5th (World Environment Day). The slogan for the day is, “If we drive for one less day, we can have one more nice day.”So far, more than 200,000 drivers have shown their support. "We can't control the weather, but we can choose not to drive," said Wu Zhonghua, a car club chairman. Beijing is trying to have 238 blue sky days this year. In the first quarter of 2007, Beijing only had 52 blue sky days. This was 11 days less than the number for the same period last year. Much of the dust(尘土) comes from the desert, but cars cause most of the air pollution. We must do more for No Car Day.1．No Car Day was started _______.A．to save moneyB．to control the weatherC．to make the air cleaner2．The No Car Day activity asks Beijing drivers _______.A．not to work on World Environment DayB．to ride a bike or walk instead of driving to work once a monthC．to leave their cars at home for a week each month3．When is World Environment Day?A．On July 5th.B．On June 5th.C．On September 22nd.4．Which of the following about No Car Day is WRONG?A．It was started in France in September, 1998.B．It is supported by over 1,000 cities around the world.C．It was first started by a car club chairman in Beijing.5．cause most of the air pollution.A．Dust. B．Cars C．BeijingersD16、1．You can ________ in the African village.A．watch an old dance B．enjoy the village lifeC．find sea animals D．try the future life2．People in the old village live a ______ life.A．rich B．poor C．happy D．simple3．If Tomwants to know the life in the future, he can go to ________.A．The Future Tower B．The Wonder LandC．The Old Village D．The Underwater WorldE17、For this little boy,it was the coldest winter.In that winter,his father lost a leg in an accident. He couldn’t go out to work again.From then on,his father became another person. He often lost his temper and beat him.One night, the boy was walking slowly lonely on the street. He passed a lovely small shop, He looked at some nice packages(包) of coffee quietly for a long time. An idea came into his mind .He knew his father loved coffee and he knew stealing was no good.But all he could think of was his father’s smile.He soon put a package of coffee into his jacket and ran back home.He ga ve the coffee to his father,who gave a smile that the boy had missed for so long.But,unfortunately,before his father could taste the coffee,the shopkeeper broke in and caught the boy. His father beat him again.Years later, he became a successful businessman. One day, his mother called and said his father wanted to see him. Busy working, he refused. Weeks later, he heard the sad news that his father had______When he went through the relics（衣物）,he found an old box.Inside the box was the coffee that he had stolen from the shop.On the cover was his father’s handwriting:“Th egift from my son.”There was also a letter:“Dear son,I’m a failure as a father. But I also have a dream—to own a coffee shop, where I can make cups of coffee for you. I’m sorry I didn’t make it.”Sadness suddenly occupied him. He regretted not meeting his father for the last time, and decided to complete hi s father’s dream. After quitting his own job, he started a coffee business.The coffee business is now a huge success. And the little boy is Howard Schultz—the owner of the multinational corporation Starbucks.1．Why did the boy’s father become a different person？A．Because the boy didn’t study very hard.B．Because he lost a leg and couldn’t support the family.C．Because he lost an arm in an accident.D．Because it was the coldest winter.2．From the second passage, we could infer that________________.A．the boy wanted to taste the delicious coffeeB．the boy liked stealing thingsC．the boy wanted to make his father happyD．the boy’s mother liked drinking coffee3．What did the boy regret most?A．Not meeting his father for the last time.B．Stealing coffee in a coffee shop.C．not completing his father’s dream.D．Getting troubling for his family.4．What does the underlined part “pass away” mean?A．出国B．通过C．外出D．去世5．The writer wants to tell us _____________.A．Howard Schultz started a coffee business to co mplete his father’s dreamB．the father was kind to the boy and never beat himC．the little boy is Howard Schultz—the owner of KFCD．the boy’s mother loved his coffee so much that she kept it in an old boxF18、Nina felt nervous this morning. She couldn’t b elieve that she decided to try out for a talent show. She loved to sing but she disliked singing in front of other people.Taking a deep breath, she pushed open the door of the theater and went inside.The room was filled with laughing children. Nina saw Luz, James and others from her class. The bright, sunny room left her no place to hide. A few teachers sat on chairs. They waited for the children to become quiet.“Hi, Nina!” Luz called out. “I didn’t think you would try out. You are so timid(胆怯的) in front of people.”“That’s not true,” Nina said. “I’m not shy at all.”“Yeah, right,” Luz chuckled(轻声地笑) and ran off to find a seat.One by one the students got up on the stage(舞台) and did their acts.“Nina Martinez!” a voice called out. It was Mrs. Brent, the m usic teacher. Nina rose from her chair. She felt small as she walked to the huge, empty stage. Her face was hot and her shaking hands were as cold as ice.“I-I-” Nina began, and then stopped. “I can’t,” she said softly.“Close your eyes,” said Mrs. Brent gently. “Forget about everyone else. Just sing.”Nina felt silly, but she gave it a try. She closed her eyes and raised her voice and sang out. Her hands stopped shaking. The song was so nice that everybody enjoyed it.Nina heard Mrs. Brent clap (鼓掌) loudly at the end of her song. “That’s the first time I have really heard your voice,” she said. “You are in the show!”Nina let out a big sigh(叹息) and smiled happily.1．What was the weather like that day?A．Sunny. B．Rainy. C．Snowy. D．Cloudy.2．Why did Luz laugh as he ran off to his seat? Because .A．he thought Nina looked sillyB．he thought Nina was very funnyC．he did not believe Nina was telling the truthD．he did not believe Nina had a good music teacher3．When Nina walked to stage, her face was hot and her hands were cold. That’s becauseshe was .A．very excited B．badly illC．too nervous D．so happy4．Mrs. Brent told Nina to just sing for herself. It showed that Mrs. Brent .A．wanted Nina to do wellB．thought Nina’s voice was too softC．did not think Nina would be in the showD．did not think Nina would remember the song5．Which word best describes Nina at the end of the story?A．Silly. B．Lucky. C．Proud. D．Terrible.Ⅴ.书面表达19、践行文明礼仪从我做起，下周五要举办＂文明礼仪伴我成长＂为主题的英文征文比赛，请根据下面要点写一篇英文短文参赛。
高考生物大一轮复习 第四单元 第3讲 细胞的分化衰老凋亡和癌变练习
闪堕市安歇阳光实验学校第3讲细胞的分化、衰老、凋亡和癌变一、选择题1．下列关于人体细胞增殖、分化、衰老、凋亡和癌变的叙述，正确的是( ) A．细胞的分化程度越高，全能性越强B．癌细胞具有细胞增殖失控的特点C．正常细胞的衰老凋亡必将使个体衰老死亡D．幼年个体生长需细胞增殖，成年后不需细胞增殖解析：细胞分化的程度越低，细胞的全能性越强，A错误；癌细胞是不受机体控制的、连续进行分裂的恶性增殖细胞，B正确；人是多细胞生物，正常细胞的衰老凋亡与个体的衰老死亡不是同步的，C错误；成年个体中细胞的更新也需要细胞增殖，D错误。
答案：B2．(2019·河北衡水调研)关于细胞凋亡的叙述，不正确的是( )A．胚胎细胞中存在与细胞凋亡有关的基因B．被病原体感染的细胞的清除属于细胞凋亡C．细胞凋亡的过程中有新蛋白质的合成D．细胞坏死是有害基因选择性表达造成的解析：人体正常细胞中都存在与细胞凋亡有关的基因，A正确；被病原体感染的细胞的清除是机体主动免疫的结果，对机体有利，属于细胞凋亡，B正确；细胞凋亡是由基因控制的，而基因表达过程中合成了与细胞凋亡有关的蛋白质，C正确；细胞坏死是在种种不利因素的影响下引起的，不受基因控制，D不正确。
答案：D3．下列关于细胞分化、衰老、凋亡和癌变的叙述，不正确的是( )A．细胞分化是基因选择性表达的结果，细胞分化成熟后一般不再分裂B．个体发育过程中细胞的衰老过程对于生物体发育产生了积极影响C．浆细胞能进行mRNA的合成，说明它已经产生了分化D．癌症可以看作是一系列的原癌基因与抑癌基因的变异逐渐积累的结果解析：细胞分化是基因选择性表达的结果，高度分化的成熟细胞不再分裂，A 项正确。
个体发育过程中的细胞衰老，对个体发育是有利的，B项正确。
已经分化和未分化的细胞都能进行转录合成mRNA，C项错误。
根据大量的病例分析得知，癌症并不是单一基因突变的结果，在一个细胞中至少发生5、6个基因突变，才会使细胞癌变，D项正确。
草鱼凝集素分子的基因克隆与进化分析
米亚双 程传波 河南师范大学草鱼凝集素分子的基因克隆与进化分析分子质量为２９８６８．１，等电点为５．０３，４６￣６８ａａ为跨膜区，１２５￣２５６ａａ为ＣＲＤ。
氨基酸序列上的第１２５、１３６、１５３、２３２、２４７、２５５位置上含有６个高度保守的半胱氨酸残基（三角内），并且该凝集素只有一个ＣＲＤ（下划线部分）。
氨基酸序列还含有一个结合甘露糖的糖识别结合位点即ＥＰＮ基序（椭圆内）和一个作为Ｃ型凝集素重要标志的ＷＩＧＬ序列（矩形内）。
草鱼凝集素的系统进化分析。
用生物信息学ＭＥＧＡ４．０以邻接法（ＮＪ法）构建草鱼，斑马鱼，鲫鱼，雀鳝，原鸡，家鼠，牛，人等Ｃ型凝集素蛋白的系统进化树。
从图２可以看出系统进化树分为三大支，草鱼同斑马鱼，鲫鱼，雀鳝，白斑狗鱼，虹鳟，大西洋鲑进化关系较近，处于一支，说明Ｃ型凝集素在进化过程中，草鱼同硬骨鱼的亲缘关系较近，其中与斑马鱼的关系最近。
草鱼凝集素基因的同源性分析。
用ＤＮＡＭＡＮ对所选物种凝集素的ＣＲＤ进行多序列比对发现，草鱼凝集素ＣＲＤ与斑马鱼凝集素ＣＲＤ的相似度达到９０％，同鲫鱼、雀鳝、大西洋鲑和虹鳟的相似度分别达到８３％、６３％、５３％和５１％。
序列比对结果鱼是我国重要的养殖淡水鱼，其产量以及产值居于鱼类养殖业的前列。
凝集素是一类具有糖结合专一性，并与之非共价可逆结合的非酶、非免疫来源的蛋白质，其中把活性依赖于Ｃａ２＋者称为Ｃ型凝集素。
Ｃ型凝集素都具有一个或多个糖结构识别域（Ｃａｒｂｏｈｙｄｒａｔｅ－ｒｅｃｏｇｎｉｔｉｏｎ ｄｏｍａｉｎ，ＣＲＤ）。
鱼类中所存在的天然凝集素分子在其非特异性免疫中占据重要地位，是鱼类抵御异己物质入侵的一道防线。
材料与方法材料。
在超市购买健康的草鱼，体长大约为３０ｃｍ，体重为１．４７ｋｇ。
方法。
（１）草鱼凝集素基因的克隆：从草鱼组织中提取草鱼ＲＮＡ，并通过ＲＴ－ＰＣＲ技术克隆获得草鱼凝集素基因。
采用反转录试剂盒合成ｃＤＮＡ。
以草鱼的ｃＤＮＡ为模板，根据已设计好的引物，运用ＰＣＲ技术获得草鱼凝集素基因。
闽南语音标入门
闽南语国际音标(白话字Peh-oe-ji）<一>字母Aa Bb Cc Ee Gg Hh Ii Jj Kk Ll Mm Nn Oo Pp Ss Tt Uu<二>子音(声母)p-ph-b-m--t-th-l-n -[p‘]--[m]--[t]-[t‘]-[l]-[n] 卑-披-未-棉--知-耻-离-尼k-kh-g-ng-h-ch-chh-s-j [k]-[k‘]-[g]-[]-[h]-[ts]-[ts‘]-[s]-[dz] 基-欺-疑-硬-希-之-痴-诗-儿(1).子音j今仅见于漳属各县市(漳浦县除外)和台湾，泉属的惠安、永春以及厦门的同安区偶有见到。
今厦门、泉州大多并入子音l, 漳浦并入g.(2).h, p, t, k兼用作入声韵尾符号，做入声韵尾符号时，只有成阻动作，不发出声来。
(3).中括号内为国际音标。
<三>母音(韵母)1.基本元音 a e o o/ou i u ee ir er [a] [e] [o] [] [ i ] [u] [ε] [ш] [γ] 阿鞋窝乌衣污哑猪锅(1).前六个为厦门音基本元音,漳州音增加ee;泉州音增加ш和γ2.介音韵ai au ia oa iau oai [ai][au][ia][ua][iau][uai] 哀欧耶蛙妖歪oe ui io iu iou [ue][ui][io][iu][i] 话威腰尤(喏)3.鼻尾韵m ng an in ian un oan am im [m][][an][in][ian][un][uan][am][im] 呣秧安因烟温弯庵音iam eng angong iang iong （oang）（om）[iam][i][a][] [ia] [ua] [m] 阉英红汪央央(风) (森) (1) “风”是同安音，“森”是漳州音4.鼻化韵aN iN eN oN uN iaN oaN （oeN）[a~] [i~] [e~] [~] [u~] [ia~] [ua~][ue~]馅圆婴恶囗营鞍(糜)iuN ioN uiN auN aiN oaiN iauN [iu~] [i~][ui~][au~][ai~][uai~][iau~] 杨羊黄嗷闲(关) 喵(1).aN=a; iN=i; eN=e;…,其余同理;(2). “糜”“羊”“黄”是漳州音；“闲”是同安音;(3).“囗”“嗷”“喵”是象声词5.入声韵ah-eh-oh-ouh-ih-uh-iah-ioh [a][e][o][][i][u][ia][io] 鸭-嗝-学-(膜)-(鳖)-(嗍)-页-药iuh-oah-oeh-uih-aih-auh-iauh-oaih [iu][ua][ue][ui][ai][au][iau][uai] 匊-活-狭-(血)-鸭-(雹)-蛲-囗ahN-auhN-ihN-ouhN-aihN-ehN-oaihN-mh [a~][au~][i~][~][ai~][e~][uai~][m](趿)-(荥)-囗-囗-囗-囗-囗-(默)ngh-ap-ak-at-ek-ip-it-ut [][ap][ak][at][ik][ip][it][ut] (蹭)-压-沃-遏-益-揖-乙-兀iap-iak-iat-ok-iok-oat-op- [iap][iak][iat][k][uat][p] 叶-(煏)-谒-屋-约-越-囗-(1).“aih鸭”是同安音；“op”是漳州音；(2).“囗”代表各象声词,有音无字闽南语声调调名：阴平阴上阴去阴入阳平阳去阳入调值：44 53 21 32 24 22 4标调符：不标调ˊˋ不标调^ —'代码1 2 3 4 5 7 8例一kim kím kìm kip kiâm kīm ki'p kim kim2 kim3 kip kiam5 kim7 kip8 金锦禁级咸妗及例二kun kún kùn kut kûn kūn ku't kun kun2 kun3 kut kun5 kun7 kut8 君滚棍骨裙郡滑例三tong tóng tòng tok tông tōng to'k tong tong2 tong3 tok tong5 tong7 tok8 东党栋督同洞独例四pe péèpeh pêpēpe'h pe pe2 e3 peh pe5 pe7 peh8 飞把秽伯爬倍白例五chanchán chàn chat chân chān cha't chan chan2 chan3 chat chan5 chan7 chat8 曾盏赞节层赠实注:(1).第1声(阴平)和第4声(阴入)没标调; (2).本表设计不包含"轻声"啲内容。
凝血酶原ii基因
凝血酶原II基因1. 引言凝血是人体维持血液正常状态的重要过程之一。
当血管受损时，机体会通过一系列复杂的凝血反应来形成血栓，防止过多的出血。
凝血酶原II基因（F2基因）是参与凝血反应的关键基因之一。
本篇文章将对凝血酶原II基因的结构、功能以及与疾病相关的突变进行详细介绍。
2. 凝血酶原II基因的结构凝血酶原II基因位于人类基因组的第11号染色体上，编码凝血酶原II蛋白。
该基因由14个外显子和13个内含子组成，总长度约为27千碱基对。
凝血酶原II蛋白由622个氨基酸残基组成。
凝血酶原II基因的启动子区域包含了一些调控元件，如转录因子结合位点和启动子启动位点。
这些元件对凝血酶原II基因的转录起着重要的调控作用。
3. 凝血酶原II基因的功能凝血酶原II蛋白是凝血酶的前体，在凝血过程中发挥重要作用。
凝血酶是一种酶，能够将凝血酶原转化为活性的凝血酶。
凝血酶能够加速纤维蛋白原的聚合，形成纤维蛋白，进而形成血栓。
凝血酶原II基因的突变可能会导致凝血功能异常，如血栓形成倾向性增加或出血倾向性增加。
凝血酶原II基因的突变还与一些疾病的发生和发展密切相关，如静脉血栓栓塞症、心肌梗死等。
4. 凝血酶原II基因突变与疾病凝血酶原II基因的突变是一种常见的遗传性疾病。
最常见的突变型是凝血酶原II基因G20210A突变。
这种突变会导致凝血酶原II基因的转录和翻译过程发生异常，使得凝血酶原II蛋白的水平升高。
高水平的凝血酶原II蛋白会导致血栓形成倾向性增加，增加患者患上静脉血栓栓塞症的风险。
除了G20210A突变外，凝血酶原II基因的其他突变也与疾病的发生和发展有关。
例如，凝血酶原II基因的缺失突变可能导致凝血酶原II蛋白的合成受阻，从而导致出血倾向性增加。
5. 凝血酶原II基因检测凝血酶原II基因突变的检测对于预防和治疗相关疾病具有重要意义。
目前，常用的凝血酶原II基因突变检测方法包括聚合酶链反应（PCR）和直接测序法。
这些方法可以快速、准确地检测凝血酶原II基因的突变，为个体化的疾病管理提供了重要依据。
高考生物一轮复习 第四单元 细胞的生命历程单元过关检测(四)
藏躲市安详阳光实验学校【优化方案】高考生物一轮复习第四单元细胞的生命历程单元过关检测（四）1．下图是某二倍体动物的几个细胞分裂示意图，据图判断错误的是( ) A．若按分裂的先后顺序排列，应为②→③→④→①B．图①到④构成了一个完整的细胞周期C．正常情况下，图④表示细胞两极染色体形态和数目相同D．图③所示时期是观察染色体形态和数目的最佳时期解析：选B。
由图示可知，①是有丝分裂末期，②是有丝分裂间期，③是有丝分裂中期，④是有丝分裂的后期，因此细胞分裂的先后顺序是②→③→④→①；图示缺乏细胞分裂的前期，因此图①到④不能构成一个完整的细胞周期；图④是有丝分裂的后期，细胞两极染色体形态和数目相同；图③是有丝分裂中期，是观察染色体形态和数目的最佳时期。
2．(2015·北京石景山模拟)如图为某真核细胞分裂过程中一个细胞核中DNA变化图解，下列叙述正确的是( )A．在AB段有DNA分子复制和蛋白质的合成B．在CD段该细胞中染色体数不变C．若该细胞是植物细胞，则在CD段该细胞赤道板处已形成细胞板D．若该细胞是植物细胞，则在DE段该细胞中有高尔基体起作用解析：选D。
DNA分子复制和蛋白质的合成发生在间期，AB段没有DNA分子复制，A错误；在分裂期的后期该细胞中染色体数加倍(处于CD段中)，B 错误；植物细胞有丝分裂过程中细胞板在末期形成，C错误；植物细胞中在DE 段即末期有高尔基体起作用，D正确。
3．如图是某动物细胞有丝分裂过程中的某一分裂时期示意图。
据图推断正确的是( )A．该时期细胞核糖体功能最为活跃B．此时细胞中有四个中心粒C．该图反映细胞进行基因重组D．只要不发生基因突变，就可判断4上相应位置的基因是B解析：选B 。
该细胞着丝点排列在赤道板上，有同源染色体，可判断为有丝分裂中期。
在有丝分裂间期进行DNA分子的复制和有关蛋白质的合成，此时核糖体功能最活跃，A项错误；在间期进行中心体的复制，而每个中心体由两个相互垂直的中心粒构成，故分裂中期细胞中有四个中心粒，B项正确；基因重组发生在减数分裂过程中，C项错误；2和4为同源染色体，其上存在等位基因或相同基因，所以4上相应位置的基因可能是B或b，D项错误。
凝集素
三、分类和命名
初期，以单糖结合专一性分类 – 对Glc/Man专一的 – 对Gal/GalNAc专一的 – 对L-Fuc专一的 – 对壳二糖专一的 – 对sia专一的 按凝集素来源分 按序列同源性分类
四、结构概况
种属相近的植物凝集素或不同来源但糖结合专 一性相同的凝集素，其序列和立体结构有一致 性； 一些动物凝集素与植物凝集素在一级结构上同 源性不高，但立体结构上相似； 许多凝集素活性依赖金属离子 大量beta-片层结构，耐酶解
SBA UEA
WGA BSA DBA SJA
D-GalNAC>>D-半乳糖 L-岩藻糖
D-GalNAC、NANA D-半乳糖 D-GalNAC D-半乳糖、D-GalNAC
植物凝集素的糖结合专一性
豆科 – 巨刀豆凝集素ConA：高Man糖链
不结合三、四天线杂合型糖链
– 兵豆/小扁豆凝集素LCA：带核心Fuc的三天线强结合 谷物 – 麦胚凝集素WGA:平分型GlcNAC/Sia 茄科 – 曼陀罗凝集素DSA：GlcNAc/三、四天线杂合型糖链及
食草动物致死性病原 芽孢抵抗力极强 两个质粒 – 荚膜 – 致死因子，水肿因子 疫苗与生物导弹
How anthrax toxins cause pathology
PA (protective antigen,保护性抗 原) ATR (anthrax toxin receptor) cell surface protease furin
凝集素-配体相互作用的本质
GAG-结合蛋白——GAG：离子键 凝集素——N-和O-糖链：
– 蛋白质浅表凹陷处的低亲和力结合作用：氢键、
小学三年级下册第2次英语第4单元期末试卷(答案和解释)
小学三年级下册英语第4单元期末试卷(答案和解释)英语试题一、综合题(本题有50小题，每小题2分，共100分.每小题不选、错误，均不给分)1.Which of these is a color?A. dogB. appleC. greenD. table2.Which of these is the largest?A. ElephantB. DogC. CatD. Rabbit3.Which of the following is a season?A. WinterB. BreakfastC. DinnerD. Car4.What do we use to brush our teeth?A. ToothbrushB. SpoonC. KnifeD. Fork5.Which of these is used to play music?A. GuitarB. PlateC. SpoonD. Knife6.I like playing the piano. I started learning it when I was six years old. Every day, I practice for 30 minutes. I know how to play some simple songs, and I am getting better at it. I hope one day I can play a difficult song.7.Which animal can fly?A. DogB. LionC. BirdD. Elephantst night, we ______ (have) a family dinner at home. I ______ (cook) pasta for the first time. Everyone ______ (say) it ______ (be) delicious, and I ______ (feel) very proud.9.We ______ (visit) our grandparents last weekend. They ______ (live) in a small village. Every time we ______ (visit) them, we ______ (have) a great time. This time, we ______ (help) them in the garden. We ______ (plant) flowers together.10.Peter usually ______ (go) to school by bus, but today he ______ (decide) to walk. It ______ (be) a sunny day, so he ______ (feel) happy. When he ______ (arrive) at school, he ______ (see) his friends waiting outside. They ______ (chat) and ______ (laugh) together before going inside for class.11.Which animal can fly?A. FishB. CatC. BirdD. Elephant12.Which word describes the weather when it is raining?A. SnowyB. SunnyC. WetD. Windy13.Which one is a type of tree?A. OakB. CarC. HouseD. Dog14.Which animal is the king of the jungle?A. ElephantB. TigerC. LionD. Giraffe15.Which of these is a time of day?A. WinterB. NoonC. RedD. Chair16.What is the opposite of "good"?A. HappyB. BadC. SadD. Angry17.What is the opposite of "happy"?A. SadB. TallC. ColdD. Hot18.We went to the ______ yesterday to watch a ______ movie. It was very ______, and I was a little scared. My little brother hid behind me during the scary parts. After the movie, we went to a ______ and ate ______ and drank soda.19.I _______ a good student.A. amB. isC. areD. be20.What is the plural form of “child”?A. ChildsB. ChildrenC. ChildesD. Childrens21.What do we use to write on paper?A. SpoonB. PenC. ForkD. Plate22.______ you like to play basketball?A. DoB. DoesC. AreD. Is23.What color is the grass?A. BlueB. RedC. GreenD. Yellow24.What do we use to clean the floor?A. SpoonB. PlateC. BroomD. Knife25.Which animal is the fastest?A. ElephantB. CheetahC. LionD. Rabbit26.Which of these is a fruit?A. PotatoB. BananaC. OnionD. Carrot27.What is the opposite of "hot"?A. WarmB. ColdC. CoolD. Frozen28.Which season is coldest?A. SpringB. SummerC. AutumnD. Winter29.How many legs does a cat have?A. FourB. ThreeC. TwoD. One30.They _______ happy.A. isB. areC. amD. be31.My little brother ______ (love) dinosaurs when he was younger. He ______ (collect) dinosaur toys and ______ (watch) dinosaur movies every weekend. Now, he ______ (prefer) cars and trains.32.Which one is a machine used for cooking?A. OvenB. PlateC. SpoonD. Glass33.Which of these is a day of the week?A. JanuaryB. SaturdayC. SummerD. December34.What do we use to clean the floor?A. BroomB. PlateC. SpoonD. Chair35.When you need to know the time, which of these should you ask?A. What time is it?B. Where am I?C. What is your favorite color?D. Where are my shoes?36.Which of these is a type of food?A. ShoeB. AppleC. ShirtD. Car37.Where do you live?A. I am a teacher.B. I live in Beijing.C. I like pizzA.D. I play soccer.38.Which of these is a type of tree?A. OakB. RoseC. SunflowerD. Tulip39.Which of these is used to write on paper?A. PenB. KnifeC. ForkD. Spoon40.Which of these is a color?A. TableB. GreenC. CarD. Apple41.Which of these is a shape?A. CircleB. CarC. SpoonD. Table42.Which of these is a fruit?A. CarrotB. TomatoC. CucumberD. Lettuce43.Which of these is a means of transport?A. HouseB. AirplaneC. TreeD. Chair44.What is the opposite of "hot"?A. ColdB. WarmC. HeavyD. Light45.Which of these is a season?A. SummerB. TuesdayC. SeptemberD. Friday46.Which of these is a holiday?A. ChristmasB. TableC. ChairD. Water47.Which of these is a mode of transportation?A. CarB. ChairC. PlateD. Tshirt48.Which animal is known for its ability to jump?A. ElephantB. FrogC. CatD. Dog49.Which animal can fly?A. FishB. ElephantC. BirdD. Dog50.Which one is a color?A. CatB. BlueC. PizzaD. Spoon(答案及解释)。
凝集素
• 亲和力。因为每个CRD都能独立的和糖结合， 那么CRD的簇聚提高了它的专一性和亲和力。 肝脏凝集素只含有一个CRD，而巨噬细胞的甘 露糖受体含有8个CRD。甘露糖受体相邻的 CRD可能有助于使其结合导向含有甘露糖的特 异性多价聚糖。
胶原凝素
• 胶原凝素是一类含有胶原样结构域的C型凝集 素，它们通常合成很大的含有9~27个亚基的 寡聚合体。有些胶原凝素，如甘露糖结合蛋白 和人表面活性物质SP-A组成”花束”状;而牛 的共凝素和表面活性物质SP-D形成“十字 形”。 • 牛胶原凝素-43（CL-43)是结构最简单的胶 原凝素之一，含有3条多肽链，每条链的末端 含有C-型凝集素的结构域。 • 血清胶原凝素MBP研究的较为清楚。大鼠有两 种血清MBP，被命名为MBP-A和MBP-C，有
• CD33最初被鉴定为髓鞘中的糖蛋白，是早期 髓细胞的前体标志物。CD33分子量约为70Ka。 与Siglec-5一样，它的活性完全取决于唾液酸 酶对CD33细胞的预处理。在不成熟的髓细胞 和红细胞、成熟的髓细胞中表达CD33；在成 熟的单核细胞、粒细胞、某些树突细胞种群上 低水平地表达。它也是髓样白血病细胞的可靠 标志。
C-凝集素的序列模体
内吞型受体
• 肝凝集素代表一类能够介导结合配体内吞的C 型凝集素。内吞途径包括凝集素对细胞表面配 体的识别、经被膜小窝的内化作用和复合物传 送到内吞区室，并在区室内酸性条件下，配体 和凝集素解离。凝集素再循环到细胞表面并重 复这个过程。 • 哺乳动物无唾液酸受体是三聚体且具有两个不 同基因编码的多肽链；鸡肝凝素是但一种多肽 构成的三聚体。这种以三聚体或六聚体形式存 在的凝集素增强了其对专一的糖缀合物配体的
L-选凝素
• 分子克隆研究随后分离剂CDNA相当于MEL14抗原及其人同源物，这个MEL-14蛋白质 被命名为L-选凝素。由克隆的CDNA衍生的多 肽序列显示该分子为一个I型的跨膜糖蛋白， 其大部分N-末端片段在胞外，有一系列彼此 分开的结构域， N-末端有信号肽。成熟蛋白 质N-末端片段氨基酸序列和C型凝集素家族具 有同源性。成熟的L-选凝素的N-末端的116 个氨基酸与其他C型凝集如，哺乳动物肝细胞 无唾液酸糖蛋白受体、几个甘露糖结合蛋白的
凝血因子8
凝血因子8
凝血因子8
血小板凝血因子8（FVIII）是一种血管系统中存在的关键凝血因子，在正常情况下，它是血液凝血过程中必不可少的复合体。
它是核蛋白质，
其结构主要由一种称为酰胺硫转肽键（S-S）结合的二聚体组成，抗体抗
凝血因子8常见于血小板凝血因子8（FVIII）缺陷性凝血病（乙），该
疾病是一种遗传性疾病，由血小板凝血因子8缺乏引起，从而导致血液凝
固问题。
血小板凝血因子8调节血液凝固，通过联结血小板表面紧密结构
因子（如血小板表面受体）来调节血小板凝结、稳定血小板凝结，并与血
小板表面紧密结构因子结合，使血小板的凝结协调，以维持血液的正常凝
血过程。
一旦血小板凝血因子8的水平低于正常水平，则容易出现血液凝
血问题，影响血液的流动，从而影响人的健康。
闽南语音标入门
闽南语国际音标(白话字Peh-oe-ji）<一>字母Aa Bb Cc Ee Gg Hh Ii Jj Kk Ll Mm Nn Oo Pp Ss Tt Uu<二>子音(声母)p-ph-b-m--t-th-l-n -[p‘]--[m]--[t]-[t‘]-[l]-[n] 卑-披-未-棉--知-耻-离-尼k-kh-g-ng-h-ch-chh-s-j [k]-[k‘]-[g]-[]-[h]-[ts]-[ts‘]-[s]-[dz] 基-欺-疑-硬-希-之-痴-诗-儿(1).子音j今仅见于漳属各县市(漳浦县除外)和台湾，泉属的惠安、永春以及厦门的同安区偶有见到。
今厦门、泉州大多并入子音l, 漳浦并入g.(2).h, p, t, k兼用作入声韵尾符号，做入声韵尾符号时，只有成阻动作，不发出声来。
(3).中括号内为国际音标。
<三>母音(韵母)1.基本元音 a e o o/ou i u ee ir er [a] [e] [o] [] [ i ] [u] [ε] [ш] [γ] 阿鞋窝乌衣污哑猪锅(1).前六个为厦门音基本元音,漳州音增加ee;泉州音增加ш和γ2.介音韵ai au ia oa iau oai [ai][au][ia][ua][iau][uai] 哀欧耶蛙妖歪oe ui io iu iou [ue][ui][io][iu][i] 话威腰尤 (喏)3.鼻尾韵m ng an in ian un oan am im [m][][an][in][ian][un][uan][am][im] 呣秧安因烟温弯庵音iam eng angong iang iong （oang）（om）[iam][i][a][] [ia] [ua] [m] 阉英红汪央央 (风) (森) (1) “风”是同安音，“森”是漳州音4.鼻化韵aN iN eN oN uN iaN oaN （oeN）[a~] [i~] [e~] [~] [u~] [ia~] [ua~][ue~]馅圆婴恶囗营鞍 (糜)iuN ioN uiN auN aiN oaiN iauN [iu~] [i~][ui~][au~][ai~][uai~][iau~] 杨羊黄嗷闲(关) 喵(1).aN=a; iN=i; eN=e;…,其余同理;(2). “糜”“羊”“黄”是漳州音；“闲”是同安音;(3).“囗”“嗷”“喵”是象声词5.入声韵ah-eh-oh-ouh-ih-uh-iah-ioh [a][e][o][][i][u][ia][io] 鸭-嗝-学-(膜)-(鳖)-(嗍)-页-药iuh-oah-oeh-uih-aih-auh-iauh-oaih [iu][ua][ue][ui][ai][au][iau][uai] 匊-活-狭-(血)-鸭-(雹)-蛲-囗 ahN-auhN-ihN-ouhN-aihN-ehN-oaihN-mh [a~][au~][i~][~][ai~][e~][uai~][m] (趿)-(荥)-囗-囗-囗-囗-囗-(默)ngh-ap-ak-at-ek-ip-it-ut [][ap][ak][at][ik][ip][it][ut] (蹭)-压-沃-遏-益-揖-乙-兀iap-iak-iat-ok-iok-oat-op- [iap][iak][iat][k][uat][p] 叶-(煏)-谒-屋-约-越-囗-(1).“aih鸭”是同安音；“op”是漳州音；(2).“囗”代表各象声词,有音无字闽南语声调调名：阴平阴上阴去阴入阳平阳去阳入调值： 44 53 21 32 24 22 4标调符：不标调ˊˋ不标调 ^ — '代码 1 2 3 4 5 7 8例一 kim kím kìm kip kiâm kīm ki'p kim kim2 kim3 kip kiam5 kim7 kip8 金锦禁级咸妗及例二 kun kún kùn kut kûn kūn ku't kun kun2 kun3 kut kun5 kun7 kut8 君滚棍骨裙郡滑例三 tong tóng tòng tok tông tōng to'k tong tong2 tong3 tok tong5 tong7 tok8 东党栋督同洞独例四 pe péè peh pê pē pe'h pe pe2 e3 peh pe5 pe7 peh8 飞把秽伯爬倍白例五 chanchán chàn chat chân chān cha't chan chan2 chan3 chat chan5 chan7 chat8 曾盏赞节层赠实注:(1).第1声(阴平)和第4声(阴入)没标调; (2).本表设计不包含"轻声"啲内容。
Unit4-2021-2022学年八年级英语下册单元过关与提升测试(人教版)2
Unit 4单元基础练习与测试(满分100分)I.根据汉语意思或首字母提示写出下列单词。
(每小题1分，共计10分)1. Can you _________(猜测) the meaning of the new word?2. This is a _________ (典型的) case and let me explain it to you.3. Many students have too much(压力) now.4. I don't want to _________ (竞争) with my best friend.5. WeChat’s popularity grows quickly because it’s convenient for people to ___________(交流) with each other.6. I felt very n__________when I first made a speech in public.7. Look! There are many c__________in the sky. It seems to rain.8. Could you e__________the new words for me? I can’t understand them.9．The rain_________ all day so we didn't go out.10．I am really sorry__________ you so much trouble.II.根据汉语意思完成句子，每空一词(每小题1分，共计10分)11．依我看，这是提高你英语水平的一个好方法。
________ ________ _________，it's a good way to improve your English.12．你可以删掉文中你不喜欢的内容。
植物凝集素（PHA）的提取及血凝效果研究
植物凝集素（PHA）的提取及血凝效果研究安徽技术师范学院,2002,16(1):23--25 journalofAnhuiTechnicalTeachersCollege植物凝集素(PHA)的提取及血凝效果研究于敏王志德董志芳(安徽大学生命科学院,安徽合肥230039)摘要:凝集素是一类具有糖专一性,可促使细胞凝集的蛋白质或糖蛋白,本文通过提取8种豆科植物种子中的凝集素.分别与人的四种血型红细胞悬液发生凝集反应(A 型,B型,O型,AB型),通过血凝反应的强弱程度来验证不同凝集素的血型专一性,并进一步测定其相对含量.关键词:植物凝集素;血凝;提取中图分类号:0.946.1文献标识码:A文章编号:1007—3302(2002)01—0023—03凝集素是一种非免疫源性的蛋白质或糖蛋白,在动物,植物及微生物(如细菌,病毒)中广泛存在,几乎见于各种生活的有机体,并不限于特殊的器官和组织.豆科植物的凝集素在成熟种子中占蛋白质总含量的10%左右.它由2个或4个单体组成,每个单体的分子量为25～30KD,有一个结合糖位点_lJ.凝集素不仅具有凝集诸如血细胞,淋巴细胞,精子细胞等作用,而且参与了生物体内的一些重要生理和药理过程,因此是研究生物体内细胞癌变,受精,分化及分子识别等生命过程极其有用的工具,同时作为一种试剂,凝集素不仅在l临床医学检验上有着重要地位,雨且是抗肿瘤药物(如干扰素,白细胞介素一2等)生产所需的促有丝分裂原L3-71,国外近来还报道某些凝集素对爱滋病毒也有抑制作用?.凝集素可能具有的多种生理生化作用.吸引了生物学科研工作者对其进行探讨.某些凝集素与ABO血型物质直接相关.少数凝集素具有血型专一性,即凝集素在凝集红细胞的反应中,其血凝反应与供血动物的种类和血型有密切关系.对这类自然界存在极少的血型专一性凝集素的性质,结构和功能的研究,不仅具有重要理论意义,雨且对l临床及法医学上血型鉴定收稿日期:2001—12—26具有较大应用价值.如油麻藤种子中的凝集素(MsL)即是一种人A型血专一性的凝集素_4】. PIA(利马豆凝集素)对A型血专一,L(欧洲百脉根凝集素)对.型血专一.Watkin和Morgan确立了凝集素的血型专一性和它们的糖结合血专一性的关系【.1材料和方法1.1材料1.11豆科(Leguminosae)植物之八种种子(I{暂于超市):赤豆.豇豆,花菜豆,多花菜豆,白云豆,黑菜豆,白菜,黄豆.1.1.2新鲜人血(A,B,AB,O四种血型)采于合肥市血防站)11.3试剂:0.85%NaCI溶液(生理盐水)11.4仪器:高速组织捣碎机DS一1(上海标本模型厂);冷冻离心机(上海医用分析仪器厂);光学显微镜XSP一16A(中国江南仪器厂);生物显微镜BHS(日本OLYMPUS公司);7230分光光度计(上海分析仪器厂).1.2方法12.1PHA的提取分别取8种豆子各15g,用生理盐水洗净后加100ml生理盐水吸涨24hr 后,将吸涨的豆子放入组织捣碎机中捣碎5rain, 置4℃冰箱中过夜抽提.将抽提物用四层纱布过滤,滤液5000r/min冷冻离心20min,上清液置24安徽技术师范学院2002每烧杯中4℃保存备用.1.22血凝反应测试(1)2%红细胞悬液的制备:取四种血型的新鲜人血各1Oml,加抗凝剂(柠檬酸钠)1g.用085%的生理盐反复洗涤5次,每次20oOr/rain离心5min,去上清,按红细胞压积用生理盐水配成2%的红细胞悬液.(2)平板反应:用滴管吸取豆类PHA提取液和红细胞悬液各一滴滴于载玻片上,充分混匀,静置1O min,在低倍镜下观察血凝现象,并以085%的生理盐水作对照试验.12.3PHA相对含量测定(1)体积相同试管洗净烘干称重后加入PHA提取液5ml,并以0 85%的生理盐水作对照试验.(2)各管分别同时加入2%的红细胞悬液1ml,摇匀,静置,15min之内观察血凝情况.(3)在某种豆子血凝团最先完全沉淀的同时,取出各管的上液.使其在同一刻度.此时再取2ml于7230分光光度计在620nm时测定光密度值(O13).(4)取出各管的悬浮液后,试管内仅存细胞沉淀团,此时烘干称重.1.2.4凝集程度的判别与记录液体澄清透明血细胞全部凝集于管底或平板底,轻摇可见大的凝块.为高度凝集(卅);液体稍混浊,液体中有明显的凝集物.凝集块较小,为中度凝集(+);液体混浊,仔细观察可看到液体中有很小的凝集块,为轻度凝集(+);液体与对照组相似,血细胞分布较均匀,为不凝集(一).2结果与讨论2.1结果2.1.1血凝反应测试豆类PHA提取液和红细胞悬液各一滴滴于载玻片上,观察结果如表1.表l提取液与四种血型血细胞摄集反应情况注:"一"不凝集+轻度凝集"抖"中度凝集"卅斗高度凝集由表1可以看出除豇豆和红豆的提取液外.其余六种豆子的提取液均可以使四种血型都发生凝集反应,且均未表现出血型专一性.只是发生反应的程度有所不同,其中自云豆效果最强,其中的PHA含量最高.2.12PHA相对含量的测定表2PPIA与血细胞稀释液作用后上清液OD值殛血红细胞凝集沉淀鞫干I 由表2可以看出,在同一条件下,加白云豆提取豫的试管吸收值最小,而红细胞沉淀最多,再次证明,白云豆中PHA含量是最高的.由于四种血型红细胞表面糖链的差异,各种豆子PHA一级结构的细微差异致使四种血型与八种豆子PHA的血凝反应有较太差异.但单从某种血型对八种豆子PHA的血凝反应来看,其结果与表1基本符合.四种血型的红细胞沉淀干重与O.D值呈负相关性,即某种提取液与红细胞悬液反应后的O.16卷第1期于敏等植物凝集索(PHA)的提取及血凝效果研究25 D值大,刚红细胞沉淀干重刚小;反之,().D值小,则沉淀重大.基本上达到了预期效果,但由于各种PHA液中均含杂质,且杂质的量不同,各种PHA液透光能力有一定差异,对()D值测量有一定影响,致使有一些豆类的反差不强.22讨论凝集素能和含有其结合位点互补的糖基的任何细胞结台.由于所有细胞和许多亚细胞结构都能与之结合,细胞凝集是细胞表面的糖分子结合,在细胞表面形面许多相互产叉的"桥"的结果影响凝集反应的因素除了PHA自身性质和细胞表面结构外,外界条件如PH值,离子强度及温度等有较大的影响,本实验用0.85%NaCI配制细胞悬液和提取PHA,从而确保PHA的血凝活性.随着科技的发展,预计将来有更多种类的植物凝集素被发现和提纯.更多的能识别新的特异性糖基的植物凝集素的发现将会使植物凝集素的应用更为广泛.从而为生物学,医学基础研究和临床诊断治疗提供新的手段和新的技术.[参考文献][]王遇群豆类植物凝集索及其对根瘤菌的识别作用[J]植物学通报.2000.17(2):127—132[2]孙册主编凝集索[M]北京.科学出版杜.1984[3]扬远和植物凝集紊的主要生物学作用及应用[J].生物学杂志,1994,(2):I一3[4]曾仲奎油麻腺种子凝集索的纯化及性质研究[J]生物化学杂志.1996,12(3),336—340[5]丁亮豆科植物凝集索对血细胞的凝集反应研究[J].中国细胞生物学第七届学术大会论文选集,1999lI.[6]Isab[eKinneyTcrriradeMirardas∞tos,et.ActivationofT&Bceilsbyacrudeextractofartoc~rpusin.- tegrifoliaismediatedbyaleetindistinctfromjaea[inJImm—noMetlho,1991.140197[7]江红.孙册.轼体动物凝集紊[J】生命的化学,1996,16(5):2B一31[8]FavcroJna1EurJlrranttno[,1993.23:179一l85 AbstrationofPhytohemagglutininandStudyofitsHemagglutininEffectYUMin,WANGZhi-de,DCINGZhi.一fang(SchoolofLiireScience,AnhuiUIrniversity,He{ei230039)Abstract:Phytohemagglufinin(PHA)isakindofproteinorglycoproteinItisabletoagglutini nthe erythrocytesofhumanbloodgroupAbstractPHAfromeightkindsofbeansandhavethemrea ctwiththeerythrocytesoffourhumanbloodgroup(A,.B,AB.O).Thispaperistoillustratebloodgroups pecialPHA anddetermineitscontentaceordingtohemegglutinativeleve1KeyWords:Phytohemagglutinin(PHA);Hemagglutination;Abstration。
有毒凝集素——种子里的诅咒（1）
有毒凝集素——种子里的诅咒（1）易楚终生学习，原始饮食92 人赞了该文章有一类蛋白质，会和特定的碳水化合物片段结合在一起（是结合，而不是“含有”，否则就是“糖蛋白”了），从而能把含有这些片段的碳水化合物、糖蛋白或糖脂（即含有糖分子片段的脂肪分子）集合在一起，它们被称为“凝集素”（lectin）。
因为它们的这种能力，生命体会利用一些凝集素来识别、锁定某些碳水化合物、蛋白质和细胞（表面有特定的糖蛋白）；但这种能力也会给某些生命体带来它们并不想要的化学效果。
几乎所有的生命体中（因此也是所有的食物中）都含有凝集素，其中大部分都不是我们现在要关心的——而另外一些，既无法被我们完全消化，又能在肠道的上皮细胞上捣乱，从而会造成肠道高渗透性……就成了对人类来说的“有毒”凝集素。
当然，所谓“有毒”往往不是让你立即有什么不适感（否则你就会立即停止摄入相关的食物了），而只是会偷偷摸摸、年复一年地损你……这才是可怕的。
有毒凝集素，大概可分为两类：谷蛋白（prolamin）和植物凝血素（agglutinin）。
谷蛋白谷蛋白是草和豆科植物在其种子（谷子和豆子）中用来储存氨基酸（为了后代在发芽时使用）的蛋白质，其中脯氨酸和谷氨酰胺的含量极高。
它们是谷物中蛋白质的主体（约占一半），比如小麦中的麸蛋白（也就是面粉中能成“筋”的主要部分，其中有麦胶蛋白gliadin 和麦谷蛋白glutenin，这是目前最受人们关注的，因为我们吃的小麦制品最多，而且经过人工优育和基因工程，小麦中的麸蛋白含量越来越多——能让面包和面条更好吃的“高筋面粉”……）、大米中的大米蛋白（orzenin）、玉米中的玉米蛋白（zein）、燕麦中的燕麦蛋白（avenin）、大麦中的大麦蛋白（hordein）、高粱中的高粱蛋白（kafirin）……虽然种类繁多，但是它们的氨基酸组成和序列，都非常相似。
因为我们体内的消化酶不擅长分解脯氨酸含量高的蛋白质，再加上植物的种子本身也有抑制蛋白酶的化合物（它们不想被动物消化掉，而想随粪便排出到土地里……），所以大量的谷蛋白往往不会在肠道内完全解体。
凝集素aga2与aga1亚基二硫键的形成
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文档下载后可定制随意修改，请根据实际需要进行相应的调整和使用，谢谢!并且，本店铺为大家提供各种各样类型的实用资料，如教育随笔、日记赏析、句子摘抄、古诗大全、经典美文、话题作文、工作总结、词语解析、文案摘录、其他资料等等，如想了解不同资料格式和写法，敬请关注!Download tips: This document is carefully compiled by the editor. I hope that after you download them, they can help you solve practical problems. The document can be customized and modified after downloading, please adjust and use it according to actual needs, thank you!In addition, our shop provides you with various types of practical materials, such as educational essays, diary appreciation, sentence excerpts, ancient poems, classic articles, topic composition, work summary, word parsing, copy excerpts, other materials and so on, want to know different data formats and writing methods, please pay attention!凝集素aga2与aga1亚基二硫键的形成是一种重要的生物学过程，其在细胞间相互作用中起着关键作用。
CCK8检测细胞增殖毒性的原理及注意事项之欧阳语创编
CCK8检测细胞增殖/毒性的原理、方法及注意事项时间：2021.03.01 创作：欧阳语一、CCK8检测细胞增殖/毒性的原理Cell Counting Kit-8（简称CCK-8）试剂可用于简便而准确的细胞增殖和毒性分析。
其基本原理为：该试剂中含有WST-8【化学名：2-(2-甲氧基-4-硝基苯基)-3-(4-硝基苯基)-5-(2,4-二磺酸苯)-2H-四唑单钠盐】，它在电子载体1-甲氧基-5-甲基吩嗪鎓硫酸二甲酯（1-Methoxy PMS）的作用下被细胞中的脱氢酶还原为具有高度水溶性的黄色甲瓒产物（Formazan dye）。
生成的甲瓒物的数量与活细胞的数量成正比。
因此可利用这一特性直接进行细胞增殖和毒性分析。
用途：药物筛选、细胞增殖测定、细胞毒性测定、肿瘤药敏试验CCK8的优点：•使用方便，省去了洗涤细胞，不需要放射性同位素和有机溶剂；•CCK-8法能快速检测；•CCK-8法的检测灵敏度很高，甚至可以测定较低细胞密度；•CCK-8法的重复性优于MTT 法；•CCK-8法对细胞毒性小；•CCK-8细胞活性检测试剂中为1瓶溶液，毋需预制，即开即用。
CCK8的缺点：•与MTT法相比，CCK8和XTT的价格比较贵。
•CCK8试剂的颜色为淡红色，与含酚红的培养基颜色接近，不注意的话容易产生漏加或多加。
与以往的增殖/毒性测定试剂相比较：二、CCK8检测细胞增殖/毒性的方法实验一：细胞增殖分析1、制备细胞悬液：细胞计数2、接种到96孔板中：根据合适的铺板细胞数，每孔约100ul细胞悬液，同样的样本可做3个重复。
3、37℃培养箱中培养：细胞接种后贴壁大约需要培养2-4小时，如果不需要贴壁，这步可以省去。
4、加入10ul CCK8：由于每孔加入CCK8量比较少，有可能因试剂沾在孔壁上而带来误差，建议在加完试剂后轻轻敲击培养板以帮助混匀。
或者直接配置含10%CCK8的培养基，以换液的形式加入。
5、培养1-4小时:细胞种类不同，形成的Formazan的量也不一样。
高考生物细胞活化的条件与试题
高考生物细胞活化的条件与试题Ｔ细胞的活化需要双识别、双信号。
教材上给出了两种Ｔ细胞：一种是辅助性Ｔ细胞（CD4+Ｔ细胞）和细胞毒性Ｔ细胞（CD8+Ｔ细胞），这两种细胞的活化略有差异。
辅助性Ｔ细胞（CD4+Ｔ细胞）活化所需要的条件：1.双识别：需要辅助性Ｔ细胞上的受体（TCR）识别由MHC Ⅱ类分子呈递的抗原肽和CD4对MHCⅡ的识别。
2.双信号：第一信号是抗原特异性信号，第二信号是APC 细胞与辅助性Ｔ细胞上的共刺激分子提供的刺激信号。
细胞毒性Ｔ细胞（CD8+Ｔ细胞）活化所需要的条件：这一点是很多老师疑惑的地方。
人教社答疑中给出了如下的解释：关于教材中第73页细胞毒性T细胞的激活途径。
目前教材里边只给了一个最简单的直接激活途径，就是受病原体侵染的这些靶细胞表面如果有一些足量的共刺激分子的话，它本身就可以激活T细胞。
当然了，还有间接激活途径，你看参考资料的时候会发现有间接激活途径，间接激活途径可能还需要抗原呈递细胞（APC）的帮忙，还需要其他一些细胞的帮助。
那么它们的帮助方式是什么呢？就是通过这些细胞表面产生了一些共刺激信号分子。
但是这些内容是非常复杂的，大学里只有对学免疫学类的医学七年制专业的这部分人才讲的，所以我们高中教材只是讲了一个最简单的直接激活的途径。
我想老师们的心里得明白，这个靶细胞表面有一些足够的一些共刺激信号分子。
当然，我觉得在教学过程中，如果您觉得您的学生可以理解比较复杂的间接激活的途径，你要给学生补充也没有关系，只要你的学生能理解。
细胞毒性Ｔ细胞的直接激活途径和间接激活途径是怎样的呢？人民卫生出版社出版的《医学免疫学》，对这两条途径是这样描述的：第一种方式为Th细胞依赖性的，当靶细胞低表达或不表达共刺激分子，不能有效激活初始CD8+T细胞，需要APC和Th 的辅助。
胞内产生的病毒抗原和肿瘤抗原，以及脱落的移植供者同种异体MHC抗原以可溶性抗原的形式被APC摄取，可在细胞内分别与MHCI类分子和MHCⅡ类分子结合形成复合物，表达于APC细胞表面。
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C-type lectins亚家族结构模式图
选凝素 (Selectin)
三种选择素介导炎症反应中白细胞与血管内皮 细胞的粘附 L-、E-、P-选择素的比较 – L-selectin 介导淋巴细胞(lymphocyte)的归巢 – P-selectin出现于炎症反应中内皮细胞募集嗜中性
白细胞过程的早期 – E-selectin出现于炎症反应中内皮细胞募集嗜中性 白细胞过程的后期
原发性肝癌的早期诊断
甲种胎儿球蛋白（AFP） 浓度升高是肝癌诊 断的重要因素 原发性肝癌患者血清中的AFP会出现： – 核心Fuc – 血清Tf和肝型ALP: 天线数增加，核心Fuc增加 小部分原发性肝癌患者血清AFP阴性，则可检 测Tf和肝型ALP的N-糖链结构异常。 可以分别用什么凝集素检测？
C-type lectin
Ca2+依赖的凝集素大家族。CDR具有一级结构 同源性。 发现历史：肝细胞表面的去唾液酸糖蛋白受体 ——肝凝集素
肝凝集素的发现
对象：血浆铜蓝蛋白 证据： – 1）大多数血清糖蛋白都具有sia末端 – 2）酶法使放射性标记的血浆铜蓝蛋白去唾液酸化
，再注射到兔子血液中。发现其迅速被清除。 – 3）如果末端暴露的Gal结构改变，可延长其在血 清中的半衰期。 – 4）利用唾液酸转移酶和CMP-NeuAC处理，可以 使蛋白再次唾液酸化，这样的产物半衰期可恢复 。 – 5）被清除的放射性去唾液酸糖蛋白被发现结合在 肝脏，分离出受体。
1) The acetyl group at C-5 undergoes both hydrogen-bond and van der Waals interactions with the protein;
2) The carboxyl group makes a salt brige with Arg97; 3) The hydroxyls of the glycero moiety hydrogen-bon with the protein.
两种M-6-P受体比较
CI-MRP CD-MRP
45KDa 1个155aa的重复单元 二体或四体 Mn2+>Mg2+=Ca2+ 2×10-7mol/L
亚基分子量 域结构 天然聚合状态 结合对阳离子的 依赖 与配体的亲和力
250~300KDa 15个重复单元 单体 不依赖阳离子 2×10-9mol/L
植物凝集素的应用
恶性肿瘤的诊断
– 物理学方法、免疫学方法、生化方法、病理学方法
凝集素法检测组织特异性糖蛋白糖链结构异常
• 原发性肝癌——甲种胎儿球蛋白（AFP） • 胰腺癌——RNA酶 • 肾癌——γ 谷氨酰胺转肽酶（γ - GT）
• 葡萄胎和绒毛膜上皮癌——绒毛膜促性腺激素（hCG）
分离糖蛋白 植物抗病虫基因工程
Reaggregation of sponge
动物凝集素的分类
C-type：包括selectin、collectin等，活性依赖 Ca2+ Galectin： 早期也称S-type P-type：M-6-P受体 I-type：免疫球蛋白超家族成员，与Sia(Siglec) 或其他糖结合 正五聚蛋白类(Pentraxin) 钙连蛋白(calnexin)和钙网蛋白(calcireticulin) 。。。。。。
I-type lectins
免疫球蛋白超家族成员 Siglec（Sialic acid/immuno globulin superfamily/ lectin，Siglec） 其他I-型凝集素
The interaction of Siglec-1 and sialic acidcontaining oligosaccharides
钙连蛋白和钙网蛋白
钙连蛋白(calnexin)和钙网蛋白(calreticulin)：同源性的定 位于内质网的分子伴侣，帮助糖蛋白在内质网上折叠。 识别糖基：新生肽链上单葡萄糖基末端 作用方式：calnexin/calreticulin cycle
动物凝集素功能小结(1)
与糖蛋白的分拣(sorting)投送(trafficking)有关 (p111) – 钙连蛋白与钙网蛋白 – P-type Lectin – 去唾液酸糖蛋白受体（Asialoglycoprotein
Structure of the bovine MPR with M-6-P: red, predominantly negative charge; blue, predominantly positive charge. M-6-P is shown as a stick structure ; a manganese ion is shown in green.
MR识别和迅速清除； – 促滤泡素糖链为二天线复杂型，末端为Gal和Sia， 半衰期较长。 P121~124
胶原凝素（Colletin）
含C-lectin domain和collagen-like domain，与 先天免疫有关，可激活补体系统。 – MBL：Mannose-binding lectin – Ficolins：含纤维蛋白原样和胶原样结构域。 激活补体系统的三种途径： – 经典途径 – Lectin途径 – 旁路途径
——用蓝色鲎血制成试剂，再滴入
注射液，若试剂立即凝固或变色， 就说明注射液内含有使人发热、休 克甚至死亡的细菌内毒素。
海洋无脊椎动物凝集素的生理 功能
在免疫反应中可作为识别因子与外来异物结合或覆盖在异物表 面使其失去进一步感染寄主的能力。调理素（opsonin）。
无脊椎水产动物的养殖中可作为饵料添加剂增加免疫力。
植物凝集素的糖结合专一性
豆科 – 巨刀豆凝集素ConA：高Man糖链
不结合三、四天线杂合型糖链
– 兵豆/小扁豆凝集素LCA：带核心Fuc的三天线强结合 谷物 – 麦胚凝集素WGA:平分型GlcNAC/Sia 茄科 – 曼陀罗凝集素DSA：GlcNAc/三、四天线杂合型糖链及
偏二天线型强结合
1) M-6-P is hydrogen-bonded to Arg111 and coordinated with the manganese ion.
2) The His105 hydrogen-bonded to a phosphate oxygen of M6-P may be the residue that, when protonated at low pH, causes the receptor to release M-6-P into the lysosome.
p119~121
C-type lectin亚家族
跨膜的C-lectin – I型跨膜蛋白：N-端在胞外 Selectin（选择素、选凝素）：L-、E-、P 巨噬细胞甘露糖受体（多CRD） – II型：N-端在胞质中，C-端在胞外。如肝凝集素、淋巴细胞 凝集素 可溶性C-lectin – Collectin（胶原凝素） – Lectican（凝集蛋白聚糖）：一些蛋白聚糖（versican、 aggrecan、neurocan、brevican等）的核心肽 – 无脊椎动物凝集素 – 蛇毒 – ……
P-selectin E-selectin
All known selectin ligands are transmembrane glycoproteins. All three selectins can recognize glycoproteins and/or glycolipids containing the tetrasaccharide sialyl-Lewisx (sLeX).
Galectin
1994年命名。具有Gal结合活性，并具相同的CRD。
早期称S-型，因为可溶合和需巯基乙醇维持活性； 首先从电鳗中发现具有Gal抑制的血凝活性物质； 有细胞质蛋白的许多特点：如无二硫桥、活性不依赖 金属离子、无信号序列、N-端常被乙酰化等；
定位多样，可在胞质、核内、细胞表面及间质
sLex结构
淋巴细胞归巢
淋巴细胞归巢 (lymphocyte homing)是淋巴细胞的定向 游动,包括： – 成熟淋巴细胞向外周淋巴器官归巢 – 淋巴细胞再循环，即来自血液的淋巴细胞通过毛细血管后静
脉（高内皮小静脉，HEV）进入淋巴循环，以利于免疫细胞 接触外来抗原，然后再回到血液循环
– 淋巴细胞向炎症部位(如皮肤,肠道粘膜和关节滑膜等炎症部位)
动物凝集素
动物凝集素的发现 动物凝集素的分类 各类动物凝集素的结构和功能
动物凝集素的发现历史
海绵试验(1906~1907)——第一次发现糖参与了动物细
胞之间的相互作用。
肝细胞表面去唾液酸糖蛋白受体 (Asialoglycoprotein Receptor，ASGPR)的发现 20世纪70年代，发现巨噬细胞甘露糖受体 80年代末，预测蛋白质的糖识别域取得进展
去唾液酸糖蛋白受体(ASGPR)
去唾液酸糖蛋白受体(ASGPR)仅存在于哺乳动物肝细 胞膜表面，能特异性识别和结合末端为β-Gal或 GalNAc残基的糖蛋白，其数量的变化可反映肝脏生理 及病理状况。 生理功能：控制唾液酸化糖蛋白的半衰期。 结构：含单个C-type CRD亚基的三聚体。 可用于基因靶向转移和药物靶向治疗。
补体激活途径
经典（传统） 甘露糖凝集素 替代（旁路）
途径
抗体依赖
途径
非抗体依赖
途径
激活C3形成C5转化酶
激活C5 细胞裂解