The Biogenesis Structure and Function of Biological Membranes

地球上几乎所有的生命都从植物或生活在海洋、湖泊和池塘中的简单细菌光合生物中获得所需的食物和氧气，从而支撑了所有的全球食物链。由于地球主要是水生的，这些光合细菌的数量和活性是惊人的;每年有数十亿吨光合细菌在海洋中生长。这支看不见的微生物大军栖息在每一片海洋中，甚至生长在水面以下100米处。尽管对我们来说，这些都是漆黑的深处，但光合细菌可以生长和繁衍，因为它们产生如此多的叶绿素，以至于它们可以抓住每一个经过它们的光子。不起眼的光合细菌是主要食物链的起点，使海洋中的其他生命成为可能，也养活了我们许多人。地球上有如此多的叶绿素，它的重量超过了所有人类的重量，然而，尽管它无处不在，对所有生命都很重要，但令人遗憾的是，没有人完全了解叶绿素是如何产生的。更重要的是，每个光合作用细胞内有数百万个叶绿素分子，它们必须附着在蛋白质上，然后才能收集和使用来自太阳的能量，但是尽管它至关重要，没有人了解这个附着过程。我们想知道细胞内的叶绿素和蛋白质是如何产生的，以及它们是如何组合在一起以捕获光并将其转化为ATP的，ATP为细胞生长和分裂的数千种化学反应提供动力。这一知识对我们所有人都很重要，不仅因为捕获和使用太阳能为生命提供燃料，而且它还掌握着设计和制造设备的秘密，有朝一日可以为我们提供清洁，无限的太阳能。我们如何才能获得这些知识？我们使用光合细菌，在实验室工作台上的照明瓶中快速而容易地生长，然后我们打开细菌，取出叶绿素蛋白质，看看它们是如何工作的。捕获太阳能的叶绿素蛋白被称为光捕获复合物（LHC）。就像卫星天线将微弱的电视信号集中到接收器上一样，数千个LHC并排聚集在一起收集太阳能并将其输送到少数反应中心（RC）。RC蛋白将LHC收集的能量转化为电能，在膜的两侧以正负电荷的形式存在，就像给生物电池充电一样;这驱动了ATP的产生，ATP是所有细胞的化学燃料。我们想知道细胞是如何制造这些膜的，这些膜如此高效以至于99%的福尔斯能量落在膜上都被传递到RC。为了获得如此高效的能量收集，我们知道LHC必须在膜中彼此紧密接触，但我们不知道细胞如何做到这一点。为了理解这种光合膜是如何工作的，我们必须遵循导致细胞内功能性光捕获网络的事件顺序。为了做到这一点，我们将使用原子力显微镜来“感受”每个LHC和RC的形状，因为细胞使它们形成网络，并将这些信息转化为细胞膜中所有东西的“照片”。通过对处于不同发育阶段的细胞膜反复拍照，我们可以看到大自然是如何实现这一生物工程壮举的。我们将如何使用这些知识？我们都需要电力，我们希望通过组装我们自己的人工光收集系统，并遵循LHC如何捕获能量，然后将其引导到RC，开始从自然界中吸取教训。我们能有效地利用这些能量吗？我们能把我们的人工集光系统直接“插入”光伏电池来发电吗？通过汇集来自生物学，物理学和化学的科学家团队，我们将在研究中探索这些令人兴奋的可能性。

Nearly all life on Earth gets the food and oxygen it needs from plants, or from simpler bacterial photosynthetic organisms that live in oceans, lakes and ponds, thus underpinning all global food chains. Because the planet Earth is largely aquatic the quantity and activity of these photosynthetic bacteria is stupendous; billions of tonnes of photosynthetic bacteria grow in the oceans every year. This unseen microbial army inhabits every sea, even growing 100 metres below the surface. Although to us these are inky depths, photosynthetic bacteria can grow and thrive because they make so much chlorophyll that they can grab hold of every photon of light that comes their way. The humble photosynthetic bacteria are the start of the major food chains that make other life in the sea possible and so feed many of us too. There is so much chlorophyll on Earth that it weighs more than all of humankind, yet despite its omnipresence and its importance to all life, astonishingly, nobody understands fully how chlorophyll is made. What is more there are millions of chlorophyll molecules inside each photosynthetic cell, which have to be attached to proteins before they collect and use energy from the sun, but again despite its crucial importance, nobody understands anything about this attachment process. We want to find out how the chlorophylls and proteins inside cells are made, and how they are put together to capture light and convert it into ATP, which powers the thousands of chemical reactions that enable the cells to grow and divide. This knowledge is important to us all, not just because capturing and using solar energy fuels life, but it also holds the secret of designing and making devices that one day could give us clean, unlimited energy from sunlight. How can we gain this knowledge? We use photosynthetic bacteria, quick and easy to grow in illuminated bottles on a laboratory benchtop, and we then open up the bacteria, take out the chlorophyll-proteins and see how they work. The chlorophyll-proteins that capture solar energy are called light-harvesting complexes (LHCs). In much the same way as a satellite dish concentrates the weak TV signal onto the receiver, thousands of LHCs are grouped side-by-side to collect solar energy and deliver it to a small number of reaction centres (RC). The RC protein converts the energy harvested by the LHCs to electrical energy, in the form of positive and negative charges on either side of a membrane, like charging up a biological battery; this drives the production of ATP, the chemical fuels for all cells. We want to know how the cell makes these membranes, so amazingly efficient that 99% of the energy that falls on them is delivered to the RC. To get such highly efficient energy collection we know that LHCs must be packed in close contact with one another in the membrane but we do not know how the cell manages to do this. To understand how such a photosynthetic membrane works we must follow the sequence of events that leads to the functional light harvesting network inside the cells. To do this we will use an atomic force microscope to literally 'feel' the shapes of each LHC and RC as the cell makes networks of them and turn this information into a 'photograph' of where everything is in the membrane. By taking repeated pictures of membranes at different stages in their development we can see how nature achieves this feat of bio-engineering. How will we use this knowledge? We all need electricity and we want to make a start on learning lessons from nature by assembling our own artificial light harvesting system and following how the energy is captured by LHCs then channeled to a RC. Can we channel this energy efficiently? Can we 'plug' our artificial light harvesting system directly into a photovoltaic cell to make electricity? By bringing together a team of scientists from Biology, Physics and Chemistry we will explore these exciting possibilities in our research.