Re: [問題] 幾題生物題目

看板Biology作者snark (影燕)時間8年前 (2016/01/08 11:39)推噓2(2推 0噓 3→)

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※ 引述《Dejavua (javaua)》之銘言： : 大家好想請問以下: : 12. 為什麼B不能選呢? C的訊號放大和relay protein有關, 請問1,2級傳訊是一種relay : protein 嗎？ : 21. 為什麼不能選D呢? 形成膜電位不是和ECF(Na+)/ICF(K+)有關嗎？ : 22. 為什麼不能選E? : 35. D和味覺有關的腦區是頂葉嗎？ : 52. c應該不對吧？ : 謝謝 : http://i.imgur.com/Fw0bwVH.jpg

21題 Membrane potential (also transmembrane potential or membrane voltage) is the difference in electric potential between the interior and the exterior of a biological cell. Any voltage is a difference in electric potential between two points-for example, the separation of positive and negative electric charges on opposite sides of a resistive barrier. An electric potential (also called the electric field potential or the electrostatic potential) is the amount of electric potential energy that a unitary point electric charge would have if located at any point in space, and is equal to the work done by an electric field in carrying a unit of positive charge from infinity to that point. 複習細胞膜電位將看到不只是與鈉和鉀離子濃度有關首先細胞膜兩側不只有電位梯度還有濃度梯度所以一個離子要進出細胞膜不只考慮靜電平衡還有離子濃度平衡 resting potential of animal cells is determined by predominant high permeability to potassium and adjusted to the required value by modulating sodium and chloride permeabilities and gradients. 選擇性通透的離子通道是主要負責的機制離子幫浦則幫助維持 1.隔離是維持梯度最重要的特性 2.只考慮鈉和鉀離子是不夠的兩者都是正離子實際上當然也要考慮陰離子 In a more formal notation, the membrane potential is the weighted average of each contributing ion's equilibrium potential. 3.看選項的意思transport 代表主動運輸那就忽略了離子通道還有 carrier ref: wiki: https://en.wikipedia.org/wiki/Resting_potential https://en.wikipedia.org/wiki/Membrane_potential ----------------------------------------------------------- : http://i.imgur.com/Sb31QGI.jpg

The cell releases second messenger molecules in response to exposure to extracellular signaling molecules—the first messengers. Because peptide hormones and neurotransmitters typically are biochemically hydrophilic molecules, these first messengers may not physically cross the phospholipid bilayer cell membrane to initiate changes within the cell directly—unlike steroid hormones, which usually do. This functional limitation necessitates the cell to devise signal transduction mechanisms to transduce first messenger into second messengers, so that the extracellular signal may be propagated intracellularly. An important feature of the second messenger signaling system is that second messengers may be coupled downstream to multi-cyclic kinase cascades to greatly amplify the strength of the original first messenger signal 所以通常使用second messanger 的系統有兩個原因 1. the first messengers 無法直接穿過細胞膜的時候 2. 刺激很微小需要放大訊號的時候但是也有缺點 1. 有些scond messanger 需要酵素反應來合成或活化 Secondary messenger systems can be synthesized and activated by enzymes 離子本身可以進入細胞則速度更快 2. 多步驟的放大反應也相較離子直接進入細胞要花更多時間 : http://i.imgur.com/7tlVjnR.jpg

Animal Physiology: From Genes to Organisms 作者：Lauralee Sherwood，Hillar Klandorf，Paul Yancey Parathyroid hormone (PTH), the principal regulator of Ca2+ metabolism, acts directly or indirectly on all three effector sites. It is the primary hormone responsible for maintaining Ca2+ homeostasis and is essential for maintaining Ca2+ balance PTH是essential 再來是維生素D 第三位才是 The third Ca2+-influencing hormone, calcitonin, is not essential for maintenance of Ca2+ homeostasis in birds and mammals, though has roles in other vertebrates. : http://i.imgur.com/5mjRNuR.jpg

The primary gustatory cortex is a brain structure responsible for the perception of taste. It consists of two substructures: the anterior insula on the insular lobe and the frontal operculum on the inferior frontal gyrus of the frontal lobe. 島葉和額葉各有一部份 http://www.austincc.edu/apreview/NursingPics/CNSPics/Picture14.jpg

: http://i.imgur.com/V4cDlno.jpg

the magnitude of the depolarization diminishes with distance from the site of initial depolarization, as some of the excess cations leak back across the membrane through resting cation channels ...... Another strategy to improve the passive flow of electrical current is to insulate the axonal membrane, reducing the ability of current to leak out of the axon and thus increasing the distance along the axon that a given local current can flow passively (see Box C). REf http://www.ncbi.nlm.nih.gov/books/NBK21668/ -- ※ 發信站: 批踢踢實業坊(ptt.cc), 來自: 61.230.155.146 ※ 文章網址: https://www.ptt.cc/bbs/Biology/M.1452224363.A.A64.html

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