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  • 氯-高级

    lesson content

    What do pancakes and chloroplasts have in common?
    ::煎饼和氯板有什么共同点?

    The chloroplast is the site of . Part of the photosynthesis reactions occur in an internal membrane within the . Many of the pigments and other molecules necessary for photosynthesis are embedded within these internal membranes, The chloroplast contains many of these internal membranes, allowing numerous photosynthetic reactions to occur simultaneously, and making photosynthesis very efficient. These internal membranes stack on top of each other, just like a stack of pancakes.
    ::化石是氯板的所在地 。 部分光合反应发生在内部膜中。 许多光合所需的颜料和其他分子嵌入这些内部膜中, 化石含有许多这些内部膜, 使得许多光合反应同时发生, 并使得光合反应非常有效。 这些内部膜相互叠叠叠, 就像一堆煎饼一样。

    Chloroplasts: Theaters for Photosynthesis
    ::氯聚醚:光合合成物的引演器

    If you examine a single leaf of the plant Elodea , shown in Figure  , under a , you will see within each dozens of small green ovals. These are chloroplasts , the organelles which conduct photosynthesis in plants and . Chloroplasts closely resemble cyanobacteria , containing their own circular and . In fact, the Theory of Endosymbiosis holds that chloroplasts were once independently living (prokaryotes). So when we say that photosynthesis occurs within chloroplasts, we speak not only of the organelles within plants and algae, but also of some bacteria – in other words, virtually all photosynthetic autotrophs .
    ::如果你检查下图中显示的叶洛底亚植物的单一叶子,你会在每几十个小绿叶中看到。这些是叶板,在植物和植物中进行光合的有机体。氯极与氰化细菌非常相似,含有它们自己的圆环和。事实上,环境生物学理论认为叶洛底(prokaryotes)曾经独立生活(prokaryotes ) 。 因此,当我们说光合物发生在叶绿石中时,我们不仅谈到植物和藻类中的有机体,而且谈到某些细菌 — — 换言之,几乎所有的光合体自发性养殖。

    lesson content
    Elodea (above), like all plants and algae, consists of cells which contain organelles called chloroplasts (small green ovals). If you look carefully at living cells through a microscope, you may see the chloroplasts moving slowly around the cell edges. The plant itself may not move, but this cyclosis hints at all the action within plant cells. Remember that chloroplasts are one of the main differences between plant and animal cells; animal cells do not contain chloroplasts.

    Both chloroplasts and photosynthetic bacteria contain grana , neat stacks of flattened sac-shaped membrane compartments called thylakoids . Thylakoids can be considered a sub-organelle within the chloroplast. Between the chloroplast membrane and the grana is an aqueous fluid known as stroma . Thylakoids, especially the thylakoid membrane , organize patterns of and other molecules which conduct photosynthesis, as shown in Figure  . In addition to , two basic types of molecules - pigments and electron carriers – are significant in this process. 
    ::氯板和光合细菌都含有颗粒、整齐的扁扁立的薄膜隔板,称为甲状腺。Thylakoid可以被视为氯板内的子有机体。在叶板和颗粒之间,一种水体液,称为Stoma。Tylakoids,特别是甲状腺膜,组织进行光合的其他分子的形态,如图所示。此外,两种基本分子类型 — — 色素和电子载体 — — 在这一过程中也很重要。

    lesson content
    The structure of a chloroplast shows how membrane and molecular architecture helps life processes. A chloroplast consists of thylakoid membranes surrounded by stroma. The thylakoids stack on top of each other, like a stack of pancakes. The thylakoid stacks arrange chlorophyll, accessory pigment molecules, and photosynthetic proteins to capture sunlight and allow a concentration of ions within the sacs. You can see the green color of the chlorophyll. You cannot see the electron carriers, sequenced within the sac membranes, but their arrangement helps harvest small amounts of energy from excited electrons. The thylakoid membranes contain molecules of the green pigment chlorophyll.

    Pigments and Electron Carriers
    ::颜料和电电载体

    Pigment molecules, often arranged together with proteins in large, complex photosystems within the thylakoid membrane, absorb specific wavelengths of light energy and reflect others; therefore, they appear colored. The most common photosynthetic pigment is chlorophyll , which absorbs blue-violet and red wavelengths of light, and reflects green. Various types of chlorophyll exist, including chlorophyll a and chlorophyll b. Accessory pigments absorb other colors of light and then transfer the energy to chlorophyll. These include xanthophylls (yellow) and carotenoids (orange).
    ::色素分子通常与大而复杂的光系蛋白一起排列在胸膜内,吸收特定波长的光能,并反映其他的光;因此,它们看起来色色化。最常见的光合色色素是叶绿素,它吸收蓝色紫色和红色的光波长,并反映绿色。存在各种叶绿素,包括叶绿素和叶绿素。进取色素吸收了其他光的颜色,然后将能量转移到叶绿素中。其中包括三磷(黄)和焦素(黄)。

    Electron carrier molecules are usually arranged in chains (ETCs), also within the thylakoid membrane. These accept and pass along energy-carrying electrons in small steps ( Figure  ). In this way, they produce ATP and NADPH , which temporarily store chemical energy. Electrons in transport chains behave much like a ball bouncing down a set of stairs – a little energy is lost with each bounce. However, the energy “lost” at each step in an electron transport chain accomplishes a little bit of work, including the of H + ions from the stroma into the thylakoid, which eventually results in the synthesis of ATP. Chlorophyll a is the primary electron donor in the electron transport chain.
    ::电子载体分子通常由链条(ETCs)排列,也位于甲状腺膜内。这些分子以小步骤接受和传递载能电子(图 ) 。 这样,他们生产ATP和NADPH,它们暂时储存化学能源。 运输链中的电子就像一个球跳下一套楼梯 — — 每次反弹都会失去一点能量。 然而,电子运输链中每一步的能量“丢失 ” 都完成了一点点工作,包括从波罗门到波拉科德的H+离子,最终导致ATP合成。 氯酚是电子运输链中的主要电源。

    lesson content
    This figure shows the light reactions of photosynthesis. This stage of photosynthesis begins with photosystem II (so named because it was discovered after photosystem I). Find the two electrons (2 e-) in photosystem II, and then follow them through the electron transport chain (also called the electron transfer chain) to the formation of NADPH. Where do the hydrogen ions (H+) come from that help make ATP?

    Now that you’ve met some of the key players and explored the chloroplast, let’s put them together to see how the photosynthetic process unfolds. We will divide the process into two basic sets of reactions, known as the , which of course uses sunlight, and the , which uses carbon dioxide. As you study the details, refer frequently to the chemical equation of photosynthesis. In the first stage, you’ll discover how chloroplasts transform light energy, and why we owe our ability to breathe to plants!
    ::现在,你已经遇到一些关键玩家并探索了氯板,让我们把它们放在一起看光合过程是如何展开的。 我们将把这一过程分为两组基本反应,即所谓的光学反应和二氧化碳反应。 当你研究细节时,经常提到光合的化学方程式。 在第一阶段,你将发现氯板是如何改变光能的,为什么我们应该对植物有呼吸的能力!

    Summary
    ::摘要

    • Chloroplasts are the organelles where the process of photosynthesis takes place in plants and algae.
      ::氯甲醚是植物和藻类中光合作用过程的有机体。
    • Chloroplasts have stacks of internal membranes called thylakoids; these membranes sequence pigments and electron carrier molecules for efficient photosynthesis.
      ::氯甲醚有一系列内部膜,称为甲状腺;这些膜序列色素和电子载体分子,用于高效光合作用。
    • Thylakoids create compartments, which allow concentration gradients to store energy.
      ::甲草胺可创造隔间,使浓度梯度能够储存能量。
    • Pigment molecules absorb specific wavelengths (colors) of light; chlorophyll is the primary pigment in photosynthesis.
      ::色素分子吸收了光的具体波长(彩色);叶绿素是光合作用的主要色素。
    • Electron carrier molecules form electron transport chains, which transfer energy in small steps so that the energy can be stored or used for work.
      ::电子载体分子形成电子运输链,以小步骤传输能源,以便能储存或用于工作。

    Review
    ::回顾

    1. Explain the structure of the chloroplast, and how the structure of a chloroplast makes the chemical reactions of photosynthesis more efficient.
      ::解释氯白的结构,以及氯白的结构如何提高光合作用化学反应的效率。
    2. What structure specifically absorbs specific wavelengths and therefore appears colored?
      ::哪一种结构具体吸收了特定的波长,因此看起来色色化?
    3. What is a pigment molecule? What is the major pigment of photosynthesis? What are the pigments of xanthophylls and carotenoids?
      ::什么是色素分子?光合作用的主要色素是什么? xanthophylls 和 carotenids 的色素是什么?
    4. Describe electron carriers and the electron transport chain.
      ::描述电子载体和电子运输链。
    5. Name the two stages (sets of reactions) which make up the process of photosynthesis.
      ::命名构成光合作用过程的两个阶段(反应组) 。