生物讨论专区

morphv02c01

原帖由 恩儿 于 27-3-2008 10:22 PM 发表
其实我想问一下。biology里头的polar and non-polar究竟是指什么意识？我查了字典，问了老师，也不懂

你指的polar是不是指molecules的？
polarity of molecule means thers is an uneven distributon of charge in a molecule; i.e: d+ d- (delta+ and delta-) some part of the molecules has partial charges. For example: H2O - the O atom has a partial -ve charge (d-) due to it's strong electronegativity, as so it tends to attract some electrons towards it, thus making water a polar molecule..

恩儿

原帖由 morphv02c01 于 27-3-2008 10:58 PM 发表


你指的polar是不是指molecules的？
polarity of molecule means thers is an uneven distributon of charge in a molecule; i.e: d+ d- (delta+ and delta-) some part of the molecules has partial charges.  ...

谢谢你，你解释得很清楚给我。
不过我是一个还没上中六的学生，所以看得blur blur 的
其实我要问的东西很皮毛而已。希望各位可以帮我解答。
1)non-polar molecules such as ethanol and acetone can pass through the lipid layer because they are soluble in lipid.
我的问题是polar and non-polar(就像上面的)molecules的意识是什么？和它们差别是在哪里？是不是只是看这些molecules能soluble在哪里？
就比如：the polar hydrophilic head and the non-polar hydrophobic tails??

morphv02c01

原帖由 恩儿 于 28-3-2008 04:22 PM 发表

谢谢你，你解释得很清楚给我。
不过我是一个还没上中六的学生，所以看得blur blur 的
其实我要问的东西很皮毛而已。希望各位可以帮我解答。
1)non-polar molecules such as ethanol and acetone can p ...

The polar molecules are just like i described. Non polar molecules are just the oposite way, which means the molecules does not have any partial charges : for example Acetone( Propanone )- CH3C(O)CH3 is non polar.

In this case, we are talking about the solubility of these molecules (actually polarity can also be used to explain other things) . The hydrophilic head is is polar due to the molucule that are present, in most cases, the choline group, or, the phosphate group, and thare are charges there, thus making it polar.
The hydrophibic tails are non polar because they are all hydrocarbon( CH2-CH2-CH2 . . . . . . . . . . ) . Hydrocarbon are non polar and therefore there are not soluble in water.

And in chemistry we used to say, likes attract likes.. So non polar molecules are soluble in non polar solution or condition. So acetone is soluble in lipid because both of them are non polar.

Hope i didn't confuse you, my explanation is a bit disorganised..

恩儿

哈哈。。我明白啦。。谢谢你

morphv02c01

原帖由 恩儿 于 29-3-2008 01:48 PM 发表
哈哈。。我明白啦。。谢谢你

不客气。。we love bio。。

angelit

看了之后，突然间联想到化学去了。。。 哈哈！！

darksider

大家好,小弟首次报道,要上中六了,若有问题,请帮帮忙

shingcheng

哎哟，我考完试了，拿到成绩了，才看到cari有那么多那么好的主题...
之前来都没注意到...

幸福蛋糕

我也是......有点后悔...
今年了才来...

幸福蛋糕

今年这里都没有生物生???

darksider

我是读生物的　

幸福蛋糕

你好啊. .那你是LOWER 还是UPPER 6?

darksider

原帖由 幸福蛋糕 于 2008/6/10 05:51 PM 发表
你好啊. .那你是LOWER 还是UPPER 6?

今年才刚上　

幸福蛋糕

好好加油哦...
那我有问题可以问你吗?

ylup

原帖由 幸福蛋糕 于 9-6-2008 11:57 PM 发表
今年这里都没有生物生???

这里也有一个...但也是一个生物白痴...很多需要大家的帮忙...

幸福蛋糕

原来你也是生物生...很好...越来越多了...

Jec

大家为生物专区加加油哦。多点上来分享和提问吧。

vinclam

这里有一个关于植物和一个关于人类的生物问题：
1) Can State the different between Heart Beat and Cardiac Cycle?

2) For the Open and Closure of Stomatal Pores, I don't understand why the Potassium Ion, K+ will effect the water potential of the Guard Cell but Calcium Ion, Ca 2+ will no effect the water potential of the Guard Cell..
-The K+ and Ca2+ both also is mineral Ion
-The K+ and Ca2+ both also cation
-If there are more solute,then the solute potential will increase (water potential decrease)
-K+ is caused by the out flow of the Proton ( K+ Channel activated ) but Ca2+ will cause the Proton Channel to close.. why?

*Note: 我没有答案的，请各位前辈指点指点。。谢谢。。

darksider

原帖由 幸福蛋糕 于 2008/6/10 08:45 PM 发表
好好加油哦...
那我有问题可以问你吗?

可以啊，会的话就能！
现在学到ｅｎｄｏ，ｅｘｃｏｃｙｔｏｓｉｓ罢了　

truelove2u

原帖由 darksider 于 14-6-2008 11:11 PM 发表


可以啊，会的话就能！
现在学到ｅｎｄｏ，ｅｘｃｏｃｙｔｏｓｉｓ罢了　

算快了。。==这么快就第三课了

我们只学到carbohydrate。。==