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Biology

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Biology

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Metabolism

How Cells Control Product Buildup

Description

Cells use enzymes to run biochemical reactions and make the products they need. These reactions are happening constantly, and enzymes speed them up so they happen fast enough to matter. Enzyme activity also has to be regulated. Cells need the right amounts of starting materials, intermediate metabolites, and final products.<...

Transcript

师】在一个称为反馈抑制的 调节过程中,一种反应的产物 会在产生它的代谢途径的 早期阶段抑制某种酶的活性, 因此使自身的生产变慢或关闭。 该产物实现这一目的的方式是 与酶上的一个调节位点结合 而它与结合到基质上的 活性位点不同 当产物与调节位点结合时 它在酶中引起一个确认性变化 从而抑制酶继续对反应产生催化作用 这一活动阻止 产物的过量积累 并且,一旦产物水平足够低 它就会停止继续抑制这种酶的活性 于是生产又会继续照常进行