活动运输 - 高级

Need to move something really heavy?
::要搬重的东西吗?

If you did, it would take a lot of energy . Sometimes, moving things into or out of the also takes energy. How would the cell move something against a concentration gradient ? It starts by using energy.
::如果是这样的话,它需要大量的能量。有时, 将东西移动到或离开能量中, 也需要能量。 细胞如何移动某种东西来对抗浓度梯度? 它从使用能量开始。

Active Transport
::活动交通

In contrast to facilitated diffusion which does not require energy and carries molecules or ions down a concentration gradient, active transport pumps molecules and ions against a concentration gradient. Sometimes an organism needs to transport something against a concentration gradient, such as specific ions, or glucose and amino acids . The only way this can be done is through active transport which uses transport proteins and energy that is produced by (ATP) or through an . In active transport, the particles move across a from a lower concentration to a higher concentration. Active transport is the energy-requiring process of pumping molecules and ions across membranes "uphill" against a gradient. The active transport of small molecules or ions across a cell membrane is generally carried out by transport proteins that are found in the membrane. These transport proteins have receptor regions that bind to specific molecules and transport them into the cell. Larger molecules such as starch can also be actively transported across the cell membrane by vesicular transport processes.
::与不要求能量且将分子或离子带入浓度梯度、活性运输泵分子和离子到浓度梯度的加速扩散形成对比的是,有机体有时需要将某种物迁移到浓度梯度,例如特定的离子或葡萄糖和氨基酸等浓度梯度。唯一能够做到这一点的方法是通过主动运输,使用由(ATTP)或通过(ATP)产生的迁移蛋白和能量。在主动运输中,颗粒从低浓度向高浓度移动。主动运输是移动分子和离子在膜“上坡度”之间移动的能量获取过程。小型分子或离子在细胞膜之间的有效迁移通常由在膜内发现的迁移蛋白进行。这些迁移蛋白具有与特定分子结合并输送到细胞的接收区。恒星等大型分子也可以通过微粒迁移过程在细胞膜之间积极移动。

During active transport, specialized integral membrane proteins recognize the substance and allows it access. Essentially this process is forcing a ion or molecule to cross the membrane when normally it would not. Moving a substance against its concentration gradient is known as primary active transport , and the involved in it as "pumps". This process uses the energy of ATP . In secondary active transport , energy from an electrochemical gradient is used to transport substances. This process involves pore-forming proteins that form channels through the cell membrane.
::在活性运输期间,专门的内膜内分泌蛋白识别该物质并允许其进入。 基本上,这一过程迫使离子或分子在正常情况下不会穿过膜。 将一种物质移到其浓度梯度上称为初级活性运输,其中所涉物质称为“泵 ” 。 这个过程使用ATP的能量。 在二级活性运输中,电化学梯度产生的能量被用于运输物质。 这个过程涉及通过细胞膜形成通道的孔状蛋白。

Primary Active Transport
::初级主动交通

Primary active transport involves an integral membrane protein and the energy from ATP to transport molecules across a membrane. This type of transport is mainly done by ATPases. ATPases are a class of that catalyze the dephosphorylation of adenosine triphosphate into adenosine diphosphate (ADP) and a free phosphate ion. This reaction releases energy, which is used to drive other chemical reactions that would not otherwise occur.
::初级活性运输涉及一种复合膜蛋白,以及从ATP到分子通过膜传输的能量,这种运输主要是由ATPase进行的,ATPase是催化三磷酸烷磷酸酯脱硫成二磷酸甲酯(ADP)和一种免费磷酸盐离子的一种类别,这种反应释放能量,用来驱动其他不会发生的化学反应。

One ATPase necessary to all life is the , which helps to maintain the cell potential. This pump will be discussed in the Active Transport: The Sodium-Potassium Pump (Advanced) concept. Other sources of energy for primary active transport are redox energy and photon energy (light energy). Redox energy is used in the mitochondrial electron transport chain during cellular respiration. In this transport, the reduction energy of NADH is used to move protons across the inner mitochondrial membrane against their concentration gradient. An example of primary active transport using photon energy occurs during . During photosynthesis, proteins use the energy of photons to create a proton gradient across the thylakoid membrane . That energy is used to pump H ⁺ ions into the thylakoid .
::所有生命都必需的一ATPase 是一种有助于保持细胞潜力的装置。这个泵将在“主动运输”概念中讨论: 钠- Potassium Pump(高级)概念; 用于初级主动运输的其他能源来源是红氧化能和光子能量(光能)。 在细胞呼吸过程中,在线粒体电子运输链中使用红氧化能。 在这种运输中,NADH的减少能量被用来将质子移到内线粒体膜的浓缩梯度之上。 使用光子能量进行初级主动运输的例子出现在光子合成期间。 在光合作中,蛋白利用光子的能量生成质子梯度梯度,横跨甲状腺膜。 该能量被用于将H+离子泵入甲状腺。

Secondary Active Transport
::中等主动运输

In secondary active transport, which is also known as cotransport , energy is used to transport molecules across a membrane. However, in contrast to primary active transport, there is no direct coupling of ATP. Instead, the electrochemical potential difference created by pumping ions out of the cell is used. The process is called cotransport because one carrier protein mediates the transport of both substances. The two main forms of this are antiport and symport.
::在二级主动运输中,也称为联合运输,能源被用来将分子运过膜,但是,与初级主动运输不同,ATP没有直接连接,相反,使用了从细胞中抽出离子产生的电子化学潜力差异,该过程称为联合运输,因为一个载体的蛋白质介质对这两种物质的运输进行介质,主要有两种形式,即防波和交错。

Antiport and Symport
::反港和交接港

The difference between the two types of cotransport depends on the direction of transport of the molecules. A system in which one substance moves in one direction while cotransporting another substance in the other direction is called antiport . Symport is transport of two substrates in the same direction across the membrane. The protein involved in this transport is a symporter. The protein involved in antiport is an antiporter.
::两种联运的区别取决于分子的运输方向。一种物质向一个方向移动,而另一种物质向另一个方向共同运输的系统称为反port。交替式是将两个基质以同一方向运输到膜上。这种运输所涉及的蛋白质是同质运动。反质运动所涉及的蛋白质是反质运动。

The energy for these processes come from an electrochemical gradient. In such a gradient, one of the two substances is transported in the direction of their concentration gradient,and the energy derived is used to transport the second substance against its concentration gradient. Thus, energy stored in the electrochemical gradient of an ion is used to drive the transport of another solute against a concentration or electrochemical gradient. In antiport, one substance moves along its electrochemical gradient, allowing a different substance to move against its own electrochemical gradient. This movement is in contrast to primary active transport, in which all solutes are moved against their concentration gradients, fueled by ATP. In symport, one substance moves down the electrochemical gradient, allowing the other molecule(s) to move against its concentration gradient. One substance moves by facilitated diffusion, which is coupled with the active transport of the other substance.
::这些工艺的能量来自电化学梯度。在这样的梯度中,两种物质中的一种是朝着其浓度梯度的方向运输,而所衍生的能量则用于将第二种物质运输到其浓度梯度上。因此,一个离子的电化学梯度中储存的能量被用来用浓度或电化学梯度驱动另一个溶液的运输。在反转口中,一种物质沿其电化学梯度移动,允许一种不同的物质随自己的电化学梯度移动。这种移动与初级活性运输形成对照,在初级运输中,所有溶液都随其浓度梯度移动,由ATP提供燃料。在交点中,一种物质向电化学梯度下移动,允许其他分子随其浓度梯度移动。一种物质通过加速扩散而移动,与另一种物质的主动运输相配合。

Summary
::摘要

播放段落
• Active transport moves molecules across a cell membrane from an area of lower concentration to an area of higher concentration. Active transport requires the use of energy.
  ::活性迁移分子从低浓度地区跨过细胞膜移动到高浓度地区。主动迁移需要使用能量。
播放段落
• The active transport of small molecules or ions across a cell membrane is generally carried out by transport proteins that are found in the membrane.
  ::小型分子或离子通过细胞膜的活性迁移一般由在细胞膜中发现的迁移蛋白进行。
播放段落
• During antiport and symport two substances are cotransported.
  ::在防毒和防毒时,两种物质是共同运输的。

Review
::回顾

播放段落
1. What is active transport?
   ::什么是主动运输?
播放段落
2. Describe the main difference between primary and secondary active transport.
   ::说明初级和二级主动运输的主要区别。
播放段落
3. Explain antiport and symport.
   ::解释一下抗争和共鸣