1.the explanation about "signal peptides"?
does it contains the leader peptides which lead proteins to mitcondrion and chlroplast?and dose it must lay in the N piont of protien?how to say its location and fucntions?
2.in the electrical transmited chain,when produce 1H2O,how many H+ cross the inner membrane?6&10&12?i'm really confused
3.is the microsome an organelle?
hope to recieve any instructions from u!

AD:正庚烷气体检测仪、探测器、报警器

1.signal peptide不包括mitcondrion 的leader peptide .因为两者一个是边翻译边跨膜,另一个是翻译后跨膜.
chlroplast前体PROTEIN的N端的额外的 peptide 叫transit peptide or transit seqences.一般有两个区域.

2.我记不太清了我查一下.

3.microsome 一般是指离心时破碎的内质网FRAGMENTS,还包括粗面内质网上的核糖体.

2.生成1分子水,应有6分子H+ cross the inner membrane.

1.In my eyes, the leading peptides in the mt. or chl. proteins can be considered as signal peptides. Signal sequence can exist in N-teminal or middle of proteins,sometimes even in the C-terminal.
2.This problem haven no exact answer, there are many opions about this problem.
3.Usually, we are confused about microsome and microbody. In 1940s,Claude extract a submicroscopic structural particle, he coined the word microsome to name this structure. In fact it is a destroyed cell membrane system. So it is not an organelle. Microbody is an alias for peroxisome.

1. From the viewpoint of history, Signal Peptide is the very term which can be used only for Information-leading Sequence lying just within the N terminus of peptides being transmitted into sER shortly after they are synthesized. To be more exact, other information-leading sequences, like NLS (Nuclear Location Sequence),Leading peptide(toward Mitochondria) and Transit Peptite(toward Chloroplast), are just some sequences (because, in some cases, it was made up of discontinual sequences) located in somewhere of the peptides newly synthesized by Ribosomes. In fact, one meaning underlies the terms mentioned above that they are just some sequences leading the peptides to where they should dwell, and so, in some sense, they can be designated Signal Peptide.
Following is the defination searched by Internet. Maybe it's helpful for us to get insight for this term of signal peptide.
Signal Peptide: A peptide present on proteins that are destined either to be secreted or to be membrane components. It is usually at the N terminus and normally absent from the mature protein. Normally refers to the sequence (ca 20 amino acids) that interacts with signal recognition particle and directs the ribosome to the endoplasmic reticulum where co translational insertion takes place. Could also refer to sequences that direct post translational uptake by organelles. Signal peptides are highly hydrophobic but with some positively charged residues. The signal sequence is normally removed from the growing peptide chain by signal peptidase, a specific protease located on the cisternal face of the endoplasmic reticulum.
2. Maybe your question is about Electron-Transport Chain that is built in inner membrane of Mitonchondria. THis hyperlink adress may be helpful:http://202.127.18.160/freebbs/article.asp?id=10269.
3.I totally agree with views of other two companies, especially with that of zizhike!

leader peptide与 signal peptide不应混为一谈,目前些生化专家不把两者分开,但细胞生物学专家还是区别开两者，比如汪坤仁，翟中和,杨福愉，丁明孝,陈建国等,朱玉贤，钱凯先等也这样主张. 如果将signal peptides的概念扩大,那么其原有概念，我们还是需要设个词来定义，目前还未这样做.实际上,leader peptide与 signal peptide的区别很大,不仅是AA SEQENCE和种类或涉及的细胞器而且跨膜机理也不同，signal peptide会形成绊环结构,转运过程中的各种蛋白质和酶在前两者间也很不同。 而NLS是另外一种情况,NLS不被切除,因为它们引导PROTEIN跨核膜入核,它们在正常情况下不被切除,因为真核CELL分裂时核膜要解体分裂结束核膜,重建这样许多膜内的PROTEIN尚未入核所以要靠NLS重返核内。它与以上二这之间的差别也不小。 问题在于： 1。如果将signal peptide的定义扩大，那么跨内质网膜运输的翻译与转运同步的引导的多肽序列又应叫什么？ 2。对三种引导序列就算给出定义一个大的概念，那么考虑到三者的不同，我们不应再设定或保留三个子定义以区别吗？ 3。跨chlroplast膜运输的PROTEIN的机理更加模糊，目前更多的细节还未搞清，我们在此时就认为它的引导序列与前三者中一类的区别肯定比其它两类小，恐怕为时太早了吧？ 总之，对跨膜引导序列的定义我赞成分三类或四类的观点，而且我反对仅仅认为这些概念是历史延续它们更多的是现实的要求。 (仅供参考)

非常感谢各位学长的指点。我觉得按照翟中和的书，信号肽signal peptide主要指知道蛋白质去内质网的氨基酸序列，可位于N，C端或中央。是否引导蛋白质去其他细胞器的序列可归为信号序列（singal sequences）（包括信号斑singal patches）？
还有一个问题：我不明白线粒体内膜上的ATP合成酶水解ATP的机制是怎样的？

第一个问题我个人认为可以这样说.
第二个问题我得查一下,我现在虽有答案,但是觉得有些牵强.

信号斑singal patches只是一种空间结构吧?
不能说是singal sequences,我想.