4.30 钠-钚泵-高级
Section outline
-
What is this incredible object?
::这是什么不可思议的东西?Would it surprise you to learn that it is a human ? The image represents an active human nerve cell. How nerve cells function will be the focus of another concept. However, processes play a significant role in the function of these cells. Specifically, it is the sodium-potassium pump that is active in the axons of these nerve cells.
::你会惊讶地知道它是人类吗?图像代表了活跃的人类神经细胞。神经细胞的功能将如何成为另一个概念的焦点。然而,过程在这些细胞的功能中起着重要作用。具体地说,正是钠-钾泵在这些神经细胞的轴中很活跃。The Sodium-Potassium Pump
::钠-钚泵Carrier proteins can work with a concentration gradient (passive transport), but some carrier proteins can move solutes against the concentration gradient (from low concentration to high concentration), with energy input from ATP . As in other types of cellular activities, ATP supplies the energy for most active transport. One way ATP powers active transport is by transferring a phosphate group directly to a carrier protein. This may cause the carrier protein to change its conformation, which moves the molecule or ion to the other side of the membrane. An example of this type of active transport system, as shown in Figure , is the sodium-potassium pump, or Na + /K + -ATPase , a transmembrane ATPase, an integral membrane protein that exchanges sodium ions for potassium ions across the plasma membrane of cells. The sodium-potassium pump is found in the plasma membrane of almost every human cell and is common to all cellular life. It helps maintain resting potential , especially in following a , and regulates cellular volume.
::载体蛋白可以使用浓度梯度(被动迁移)发挥作用,但一些载体蛋白可以使用ATP的能量输入,用浓度梯度(从低浓度到高浓度)来移动溶液。与其他种类的蜂窝活动一样,ATP为最活跃的运输提供能量。ATP的一种方式是将磷酸盐组直接转移给载体蛋白,这可能导致载体蛋白改变其相容性,将分子或离子移动到膜的另一侧。如图所示,这种活性运输系统的一个实例就是钠-泵,或纳+/K+-ATPase,一种中成膜ATPase,一种有机的膜蛋白蛋白,在细胞的等离子膜上将钠离子交换钾离子。钠-钾泵存在于几乎所有人类细胞的等离子膜中,并且对所有细胞生命都很常见。它有助于保持休息潜力,特别是在细胞体积之后。The sodium-potassium pump system moves sodium and potassium ions against large concentration gradients. It moves two potassium ions into the cell where potassium levels are high, and pumps three sodium ions out of the cell and into the extracellular fluid.
::钠-钾泵系统将钠和钾离子移动到大浓度梯度上,将两个钾离子移入钾含量高的细胞,并将三个钠离子泵出细胞,进入外细胞液。The Mechanism
::余留机制机制As is shown in Figure , the sodium-potassium pump transports Na + ions and K + ions in the following manner:
::如图所示,钠-钾泵输送纳+离子和K+离子的方式如下:-
The sodium-potassium pump binds ATP and three intracellular Na
+
ions.
::钠-钾泵结合ATP和三个细胞内 Na+离子。 -
ATP is hydrolyzed resulting in adenosine diphosphate (ADP) and an inorganic phosphate. The free phosphate phosphorylates the sodium-potassium pump.
::亚磷酸酯被水解,产生亚甲二氧磷酸酯和无机磷酸酯,自由磷酸磷酸酯是钠-钾泵。 -
A conformational change in the pump exposes the Na
+
ions to the outside. The phosphorylated form of the pump has a low affinity for Na
+
ions, so they are released.
::泵的整形变化将 Na+ 离子暴露在外表。 泵的磷酸末状对 Na+ 离子的亲近性较低, 所以它们被释放了 。 -
The pump binds two extracellular K
+
ions. This causes the dephosphorylation of the pump, reverting it to its previous conformational state, transporting the K
+
ions into the cell.
::泵将两个外细胞K+离子捆绑在一起,导致泵脱光,使其恢复到以前的同质状态,将K+离子运入细胞。 -
The unphosphorylated form of the pump has a higher affinity for Na
+
ions than K
+
ions, so the two bound K
+
ions are released.
::泵的无磷化形式 Na+ 离子的亲近性高于K+ 离子,因此两个捆绑的K+ 离子被释放。 -
ATP binds, and the process starts again.
::APT 绑定, 程序又重新开始 。
Summary
::摘要-
The sodium-potassium pump is an example of an active transport membrane protein/transmembrane ATPase.
::钠-钾泵是活性飘移膜蛋白/半导体ATPase的例子。 -
Using the energy from ATP, the sodium-potassium moves three sodium ions out of the cell and brings two potassium ions into the cell.
::用ATP的能量,钠-钾将3个钠离子移出细胞,并将2个钾离子带入细胞。
Review
::回顾-
What is the sodium-potassium pump?
::什么是钠-钾泵? -
Why is the pump called a transmembrane ATPase?
::为什么这个泵叫做变压器ATPase? -
Outline how the sodium-potassium pump works.
::说明钠-钾泵是如何工作的。
-
The sodium-potassium pump binds ATP and three intracellular Na
+
ions.
