What is the lecture mainly about? According to the professor, what is an advantage of using plant seeds rather than plant leave

admin2022-07-28  51

问题 What is the lecture mainly about?
According to the professor, what is an advantage of using plant seeds rather than plant leaves to extract proteins?
Listen to part of a lecture in a biology class.
    Professor:
    I’m sure most of you know that we’ve been able to extract certain compounds from plants for use in medicine. Eh, compounds like proteins from some plants can be used in medicines as antibodies in vaccines. And we can even cause some plants to produce certain proteins by incorporating DNA into the plant cells, usually in the leaves. We then extract the proteins to use as antibodies. However, we’ve never been able to produce enough protein to make the process worthwhile. It hasn’t been practical until now.
    Now it appears that it’s possible to get a large amount of usable protein from plants. Some researchers have recently succeeded in doing this by using plant seeds to produce these proteins rather than leaves or the other parts of the plant.
    Now there are a number of advantages to get protein from plant seeds to produce antibodies. But we have to be sure that these proteins are just as effective as human proteins. And so far the researchers show that antibodies produced from plant seeds protein are effective in humans, which is great. Because typically, antibodies for vaccines and medicines too are produced from micro-organisms like yeasts or bacteria, and it’s a rather complicated process.
    OK, so what makes plant seeds good production units? Well, for one thing, there are lots of them, right? One plant can produce a lot of seeds and then there is the issue of storage. Seeds can be stored for long periods of time and the protein retains its effectiveness.
    Now that’s not true with other parts of the plant. Leaves for instance, you can’t store them very long, which means you have to get that protein out right away as soon as it’s produced. But using plant seeds as production units allows you to isolate the protein whenever you need it, and you can transport seeds all over the world, even the places where refrigeration might be a problem, not so for yeasts and bacteria, but with seeds, it seems quite possible that we’ll be able to supply vaccine to places that need them. Whereas before this, transporting and preserving these products after a long distance simply wasn’t feasible. And another major benefit of extracting plant proteins for medical use is cost-effectiveness. Unlike the production of proteins for medicinal purpose using yeasts or bacteria like insulin which is a vital protein used in medications, extracting protein from seeds doesn’t require high-tech production labs with all kinds of equipment, and since refrigeration is not crucial for maintenance or transport, it’s just much less expensive to store and maintain plant seeds than other sources of protein. We estimate the total production cost to be 10 to 100 times lower.

选项 A、Proteins can be extracted more quickly from seeds than from leaves.
B、Proteins from seeds are more effective as medication.
C、Seeds can be stored without the proteins’ losing their effectiveness.
D、A single seed provides more protein than a single leaf.

答案C

解析 题目询问利用植物种子而不是叶子来提取蛋白质的好处。教授先提到了用植物种子提取蛋白质的好处:可以长期储存,且蛋白质保持有效。接着,他提到了用叶子提取蛋白质的缺点:树叶难以长期储存,蛋白质必须马上被提取出来。因此,C项“种子可以在不丧失蛋白质效力的情况下被储存”是相较之下植物种子的好处。A项“从种子中提取蛋白质比从叶子中提取蛋白质更快”、B项“种子中的蛋白质作为药物更有效”和D项“一粒种子比一片叶子提供的蛋白质更多”都没有依据。
转载请注明原文地址:https://jikaoti.com/ti/XFhYFFFM
0

最新回复(0)