问题 单项选择题

属于脂肪组织中合成甘油三酯的原料是()

A.甘油

B.3-磷酸甘油

C.3-磷酸甘油醛

D.1,3-二磷酸甘油酸

答案

参考答案:B

解析:

储存在脂肪细胞中的脂肪(甘油三酯),被脂肪酶逐步水解生成游离脂肪酸及甘油并释放入血以供其他组织氧化利用,这样的过程称为脂肪动员。所以脂肪动员的产物包括游离脂肪酸和甘油。脂肪组织中合成甘油三酯主要按甘油二酯途径进行,其利用经糖酵解途径生成的3-磷酸甘油及脂酰CoA为原料合成甘油三酯。肝、肾等组织含有甘油激酶,能利用游离的甘油,使之磷酸化生成3-磷酸甘油来合成甘油三酯;而脂肪细胞缺乏甘油激酶,因此不能利用甘油合成甘油三酯。其他选项均与甘油三酯合成无关,是糖酵解及其在红细胞中的侧支循环2,3-二磷酸甘油酸旁路(2,3-BPG旁路)的中间产物。

阅读理解

阅读理解。

     After the Summer Olympics are over, when all the athletes and viewers have gone home and the television

audience has switched off, another group of athletes and fans will arrive at the host city, and another

competition will begin. These are the Paralympics, the games for athletes with a disability.But in Beijing in 2008,

for the first time, one of the greatest Paralympics will not be taking part.

     She is a British by the name of Tanni Grey-Thompson. Born with spinal bifida (脊椎裂) which left her

paralyzed from the waist down, Tanni used a wheelchair from the age of 7. At first, she was not keen on sport,

apart from horse-riding, which gave her a sense of freedom. But in her teens, she started taking sports more

seriously. She tried swimming, basketball and tennis. Eventually she found athletics, and never looked back.

     Indeed, Tanni's athletic career took off. In 1984, when she was 15, she pulled off a surprise victory in the

100 metres at the Junior National Wheelchair Games.

     In 1988, Tanni went to her first Paralympics Games in Soul. She bronze in the 400 metres. Even greater

success followed at the 1992 Barcelona. Paralympics. Tanni won gold in the 100, 200, 400 and 800 metres

relay, setting two world records in the process. In the same year she achieved the first of her six London

Wheelchair Marathon victories.

     Tanni's enduring success has been part motivation (动机), part preparation. "The training I do that enable

me to be a good sprinter (短跑运动员) enable me to be good at a marathon too. I train 50 weeks of the year

and that keeps me prepared for whatever distance I went to race …I am still competing at a very high level,

but as I get order things get harder and I went to retire before I fall apart."

     Indeed Tanni retired finally after the Visa Paralympics World Cup in 2007. Her wish is to coach young

athletes for Beijing 2008 Olympic Games.

     In spite of ups and downs, she never takes her fate lying down. In her splendid life,she has won an amazing

eleven gold medals, four silvers and one bronze in a series of Paralympics-a top lever athletic career covering

two decades. She has won the London Wheelchair Marathon six times, more than any other competitor, and

she has set over thirty world records.

     What advice does she have for young athletes? "Work hard at your studies, and then train, train again."

1. Which of the following sports did Tanni like before thirteen?

A. Basketball.

B. Swimming.

C. Tennis.

D. Horse-riding

2. When did Tanni win her first Olympic gold medal?

A. In 1984.

B. In 1988.

C. In 1992.

D. In 2007.

3. The underlined word"that'' in the 5th paragraph refers to _____.

A. fifty weeks' training

B. being a good sprinter

C. training almost every day

D. part motivation and part preparation

4. What's the right order of the events related to Tanni?

    a. She works as a coach.

    b. She took up athletics.

    c. She won four gold medals in Barcelona.

    d. She competed in her first Paralympics Games.

    e. She achieved a victory in her first London Wheelchair Marathon.

A. b, d, c, e, a

B. a, d, b, c, e

C. a, d, c, e, b

D. b, d, a, e, c

5. What can we learn from Tanni's success?

A. Union is strength

B. Never too late to learn

C. Well begun is half done

D. No pains, no gains

单项选择题