过程

<p><img src="/895c33cf-19c5-5fb0-868a-bfa6cfc8f85f.png"/></p>

<p>

<img src="/06b25e5d-bccb-58d0-8804-60d3b9a08940.png"/>

&nbsp;</p>

<div style=" language: zh-CN; line-height: 35.0pt; mso-line-height-rule: exactly; margin-top: 4.8pt; margin-bottom: 0pt; margin-left: .38in; text-indent: -.38in; text-align: left; direction: ltr; unicode-bidi: embed; vertical-align: baseline;"><span style=" font-size: 20.0pt;"><span style=" mso-special-format: bullet; color: black; mso-color-index: 1; font-family: Wingdings; font-size: 75%;">p</span></span><span style=" font-size: 20.0pt; font-family: 华文楷体; mso-ascii-font-family: 华文楷体; mso-fareast-font-family: 华文楷体; mso-bidi-font-family: +mn-cs; mso-bidi-theme-font: minor-bidi; color: black; mso-color-index: 1; mso-font-kerning: 12.0pt; language: en-US; text-combine: letters; font-weight: bold; mso-style-textfill-type: solid; mso-style-textfill-fill-themecolor: text1; mso-style-textfill-fill-color: black; mso-style-textfill-fill-alpha: 100.0%;">NH3+CO2+3ATP+Asp+2H2O → </span><span style=" font-size: 20.0pt; font-family: 华文楷体; mso-ascii-font-family: 华文楷体; mso-fareast-font-family: 华文楷体; mso-bidi-font-family: +mn-cs; mso-bidi-theme-font: minor-bidi; color: black; mso-color-index: 1; mso-font-kerning: 12.0pt; language: zh-CN; text-combine: letters; font-weight: bold; mso-style-textfill-type: solid; mso-style-textfill-fill-themecolor: text1; mso-style-textfill-fill-color: black; mso-style-textfill-fill-alpha: 100.0%;">尿素</span><span style=" font-size: 20.0pt; font-family: 华文楷体; mso-ascii-font-family: 华文楷体; mso-fareast-font-family: 华文楷体; mso-bidi-font-family: +mn-cs; mso-bidi-theme-font: minor-bidi; color: black; mso-color-index: 1; mso-font-kerning: 12.0pt; language: en-US; text-combine: letters; font-weight: bold; mso-style-textfill-type: solid; mso-style-textfill-fill-themecolor: text1; mso-style-textfill-fill-color: black; mso-style-textfill-fill-alpha: 100.0%;">+2ADP+2Pi+AMP+PPi+</span><span style=" font-size: 20.0pt; font-family: 华文楷体; mso-ascii-font-family: 华文楷体; mso-fareast-font-family: 华文楷体; mso-bidi-font-family: +mn-cs; mso-bidi-theme-font: minor-bidi; color: black; mso-color-index: 1; mso-font-kerning: 12.0pt; language: zh-CN; text-combine: letters; font-weight: bold; mso-style-textfill-type: solid; mso-style-textfill-fill-themecolor: text1; mso-style-textfill-fill-color: black; mso-style-textfill-fill-alpha: 100.0%;">延胡索酸</span></div>

<div style=" language: zh-CN; line-height: 35.0pt; mso-line-height-rule: exactly; margin-top: 4.8pt; margin-bottom: 0pt; margin-left: .38in; text-indent: -.38in; text-align: left; direction: ltr; unicode-bidi: embed; vertical-align: baseline;"><span style=" font-size: 20.0pt;"><span style=" mso-special-format: bullet; color: black; mso-color-index: 1; font-family: Wingdings; font-size: 75%;">p</span></span><span style=" font-size: 20.0pt; font-family: 华文楷体; mso-ascii-font-family: 华文楷体; mso-fareast-font-family: 华文楷体; mso-bidi-font-family: +mn-cs; mso-bidi-theme-font: minor-bidi; color: black; mso-color-index: 1; mso-font-kerning: 12.0pt; language: zh-CN; text-combine: letters; font-weight: bold; mso-style-textfill-type: solid; mso-style-textfill-fill-themecolor: text1; mso-style-textfill-fill-color: black; mso-style-textfill-fill-alpha: 100.0%;">尿素分子中的氮，一个来自氨甲酰磷酸（或</span><span style=" font-size: 20.0pt; font-family: 华文楷体; mso-ascii-font-family: 华文楷体; mso-fareast-font-family: 华文楷体; mso-bidi-font-family: +mn-cs; mso-bidi-theme-font: minor-bidi; color: red; mso-font-kerning: 12.0pt; language: zh-CN; text-combine: letters; font-weight: bold; mso-style-textfill-type: solid; mso-style-textfill-fill-color: red; mso-style-textfill-fill-alpha: 100.0%;">游离的</span><span style=" font-size: 20.0pt; font-family: 华文楷体; mso-ascii-font-family: 华文楷体; mso-fareast-font-family: 华文楷体; mso-bidi-font-family: +mn-cs; mso-bidi-theme-font: minor-bidi; color: red; mso-font-kerning: 12.0pt; language: en-US; text-combine: letters; font-weight: bold; mso-style-textfill-type: solid; mso-style-textfill-fill-color: red; mso-style-textfill-fill-alpha: 100.0%;">NH3</span><span style=" font-size: 20.0pt; font-family: 华文楷体; mso-ascii-font-family: 华文楷体; mso-fareast-font-family: 华文楷体; mso-bidi-font-family: +mn-cs; mso-bidi-theme-font: minor-bidi; color: black; mso-color-index: 1; mso-font-kerning: 12.0pt; language: zh-CN; text-combine: letters; font-weight: bold; mso-style-textfill-type: solid; mso-style-textfill-fill-themecolor: text1; mso-style-textfill-fill-color: black; mso-style-textfill-fill-alpha: 100.0%;">），另一个来自</span><span style=" font-size: 20.0pt; font-family: 华文楷体; mso-ascii-font-family: 华文楷体; mso-fareast-font-family: 华文楷体; mso-bidi-font-family: +mn-cs; mso-bidi-theme-font: minor-bidi; color: red; mso-font-kerning: 12.0pt; language: en-US; text-combine: letters; font-weight: bold; mso-style-textfill-type: solid; mso-style-textfill-fill-color: red; mso-style-textfill-fill-alpha: 100.0%;">Asp</span><span style=" font-size: 20.0pt; font-family: 华文楷体; mso-ascii-font-family: 华文楷体; mso-fareast-font-family: 华文楷体; mso-bidi-font-family: +mn-cs; mso-bidi-theme-font: minor-bidi; color: black; mso-color-index: 1; mso-font-kerning: 12.0pt; language: zh-CN; text-combine: letters; font-weight: bold; mso-style-textfill-type: solid; mso-style-textfill-fill-themecolor: text1; mso-style-textfill-fill-color: black; mso-style-textfill-fill-alpha: 100.0%;">。</span></div>

<div style=" language: zh-CN; line-height: 35.0pt; mso-line-height-rule: exactly; margin-top: 4.8pt; margin-bottom: 0pt; margin-left: .38in; text-indent: -.38in; text-align: left; direction: ltr; unicode-bidi: embed; vertical-align: baseline;"><span style=" font-size: 20.0pt;"><span style=" mso-special-format: bullet; color: black; mso-color-index: 1; font-family: Wingdings; font-size: 75%;">p</span></span><span style=" font-size: 20.0pt; font-family: 华文楷体; mso-ascii-font-family: 华文楷体; mso-fareast-font-family: 华文楷体; mso-bidi-font-family: +mn-cs; mso-bidi-theme-font: minor-bidi; color: black; mso-color-index: 1; mso-font-kerning: 12.0pt; language: zh-CN; text-combine: letters; font-weight: bold; mso-style-textfill-type: solid; mso-style-textfill-fill-themecolor: text1; mso-style-textfill-fill-color: black; mso-style-textfill-fill-alpha: 100.0%;">过程：先在线粒体中进行，再在胞液中进行。</span></div>

<div style=" language: zh-CN; line-height: 35.0pt; mso-line-height-rule: exactly; margin-top: 4.8pt; margin-bottom: 0pt; margin-left: .38in; text-indent: -.38in; text-align: left; direction: ltr; unicode-bidi: embed; vertical-align: baseline;"><span style=" font-size: 20.0pt;"><span style=" mso-special-format: bullet; color: black; mso-color-index: 1; font-family: Wingdings; font-size: 75%;">p</span></span><span style=" font-size: 20.0pt; font-family: 华文楷体; mso-ascii-font-family: 华文楷体; mso-fareast-font-family: 华文楷体; mso-bidi-font-family: +mn-cs; mso-bidi-theme-font: minor-bidi; color: red; mso-font-kerning: 12.0pt; language: en-US; text-combine: letters; font-weight: bold; mso-style-textfill-type: solid; mso-style-textfill-fill-color: red; mso-style-textfill-fill-alpha: 100.0%;">3</span><span style=" font-size: 20.0pt; font-family: 华文楷体; mso-ascii-font-family: 华文楷体; mso-fareast-font-family: 华文楷体; mso-bidi-font-family: +mn-cs; mso-bidi-theme-font: minor-bidi; color: red; mso-font-kerning: 12.0pt; language: zh-CN; text-combine: letters; font-weight: bold; mso-style-textfill-type: solid; mso-style-textfill-fill-color: red; mso-style-textfill-fill-alpha: 100.0%;">个</span><span style=" font-size: 20.0pt; font-family: 华文楷体; mso-ascii-font-family: 华文楷体; mso-fareast-font-family: 华文楷体; mso-bidi-font-family: +mn-cs; mso-bidi-theme-font: minor-bidi; color: red; mso-font-kerning: 12.0pt; language: en-US; text-combine: letters; font-weight: bold; mso-style-textfill-type: solid; mso-style-textfill-fill-color: red; mso-style-textfill-fill-alpha: 100.0%;">ATP</span><span style=" font-size: 20.0pt; font-family: 华文楷体; mso-ascii-font-family: 华文楷体; mso-fareast-font-family: 华文楷体; mso-bidi-font-family: +mn-cs; mso-bidi-theme-font: minor-bidi; color: red; mso-font-kerning: 12.0pt; language: zh-CN; text-combine: letters; font-weight: bold; mso-style-textfill-type: solid; mso-style-textfill-fill-color: red; mso-style-textfill-fill-alpha: 100.0%;">，</span><span style=" font-size: 20.0pt; font-family: 华文楷体; mso-ascii-font-family: 华文楷体; mso-fareast-font-family: 华文楷体; mso-bidi-font-family: +mn-cs; mso-bidi-theme-font: minor-bidi; color: red; mso-font-kerning: 12.0pt; language: en-US; text-combine: letters; font-weight: bold; mso-style-textfill-type: solid; mso-style-textfill-fill-color: red; mso-style-textfill-fill-alpha: 100.0%;">4</span><span style=" font-size: 20.0pt; font-family: 华文楷体; mso-ascii-font-family: 华文楷体; mso-fareast-font-family: 华文楷体; mso-bidi-font-family: +mn-cs; mso-bidi-theme-font: minor-bidi; color: red; mso-font-kerning: 12.0pt; language: zh-CN; text-combine: letters; font-weight: bold; mso-style-textfill-type: solid; mso-style-textfill-fill-color: red; mso-style-textfill-fill-alpha: 100.0%;">个高能磷酸键</span><span style=" font-size: 20.0pt; font-family: 华文楷体; mso-ascii-font-family: 华文楷体; mso-fareast-font-family: 华文楷体; mso-bidi-font-family: +mn-cs; mso-bidi-theme-font: minor-bidi; color: black; mso-color-index: 1; mso-font-kerning: 12.0pt; language: zh-CN; text-combine: letters; font-weight: bold; mso-style-textfill-type: solid; mso-style-textfill-fill-themecolor: text1; mso-style-textfill-fill-color: black; mso-style-textfill-fill-alpha: 100.0%;">，尿素合成过程不可逆。</span></div>

<div style=" language: zh-CN; line-height: 35.0pt; mso-line-height-rule: exactly; margin-top: 4.8pt; margin-bottom: 0pt; margin-left: .38in; text-indent: -.38in; text-align: left; direction: ltr; unicode-bidi: embed; vertical-align: baseline;"><span style=" font-size: 20.0pt;"><span style=" mso-special-format: bullet; color: black; mso-color-index: 1; font-family: Wingdings; font-size: 75%;">p</span></span><span style=" font-size: 20.0pt; font-family: 华文楷体; mso-ascii-font-family: 华文楷体; mso-fareast-font-family: 华文楷体; mso-bidi-font-family: +mn-cs; mso-bidi-theme-font: minor-bidi; color: black; mso-color-index: 1; mso-font-kerning: 12.0pt; language: zh-CN; text-combine: letters; font-weight: bold; mso-style-textfill-type: solid; mso-style-textfill-fill-themecolor: text1; mso-style-textfill-fill-color: black; mso-style-textfill-fill-alpha: 100.0%;">循环中消耗的</span><span style=" font-size: 20.0pt; font-family: 华文楷体; mso-ascii-font-family: 华文楷体; mso-fareast-font-family: 华文楷体; mso-bidi-font-family: +mn-cs; mso-bidi-theme-font: minor-bidi; color: black; mso-color-index: 1; mso-font-kerning: 12.0pt; language: en-US; text-combine: letters; font-weight: bold; mso-style-textfill-type: solid; mso-style-textfill-fill-themecolor: text1; mso-style-textfill-fill-color: black; mso-style-textfill-fill-alpha: 100.0%;">Asp</span><span style=" font-size: 20.0pt; font-family: 华文楷体; mso-ascii-font-family: 华文楷体; mso-fareast-font-family: 华文楷体; mso-bidi-font-family: +mn-cs; mso-bidi-theme-font: minor-bidi; color: black; mso-color-index: 1; mso-font-kerning: 12.0pt; language: zh-CN; text-combine: letters; font-weight: bold; mso-style-textfill-type: solid; mso-style-textfill-fill-themecolor: text1; mso-style-textfill-fill-color: black; mso-style-textfill-fill-alpha: 100.0%;">可通过延胡索酸转变为草酰乙酸，再通过转氨基作用，从其他</span><span style=" font-size: 20.0pt; font-family: Symbol; mso-ascii-font-family: 华文楷体; mso-fareast-font-family: 华文楷体; mso-bidi-font-family: +mn-cs; mso-bidi-theme-font: minor-bidi; color: black; mso-color-index: 1; mso-font-kerning: 12.0pt; language: zh-CN; text-combine: letters; mso-char-type: symbol; mso-symbol-font-family: Symbol; font-weight: bold; mso-style-textfill-type: solid; mso-style-textfill-fill-themecolor: text1; mso-style-textfill-fill-color: black; mso-style-textfill-fill-alpha: 100.0%;">a</span><span style=" font-size: 20.0pt; font-family: 华文楷体; mso-ascii-font-family: 华文楷体; mso-fareast-font-family: 华文楷体; mso-bidi-font-family: +mn-cs; mso-bidi-theme-font: minor-bidi; color: black; mso-color-index: 1; mso-font-kerning: 12.0pt; language: en-US; text-combine: letters; font-weight: bold; mso-style-textfill-type: solid; mso-style-textfill-fill-themecolor: text1; mso-style-textfill-fill-color: black; mso-style-textfill-fill-alpha: 100.0%;">-</span><span style=" font-size: 20.0pt; font-family: 华文楷体; mso-ascii-font-family: 华文楷体; mso-fareast-font-family: 华文楷体; mso-bidi-font-family: +mn-cs; mso-bidi-theme-font: minor-bidi; color: black; mso-color-index: 1; mso-font-kerning: 12.0pt; language: zh-CN; text-combine: letters; font-weight: bold; mso-style-textfill-type: solid; mso-style-textfill-fill-themecolor: text1; mso-style-textfill-fill-color: black; mso-style-textfill-fill-alpha: 100.0%;">氨基酸获得氨基而再生。</span></div>

<div style=" language: zh-CN; line-height: 35.0pt; mso-line-height-rule: exactly; margin-top: 4.8pt; margin-bottom: 0pt; margin-left: .38in; text-indent: -.38in; text-align: left; direction: ltr; unicode-bidi: embed; vertical-align: baseline;"><span style=" font-size: 20.0pt;"><span style=" mso-special-format: bullet; color: black; mso-color-index: 1; font-family: Wingdings; font-size: 75%;">p</span></span><span style=" font-size: 20.0pt; font-family: 华文楷体; mso-ascii-font-family: 华文楷体; mso-fareast-font-family: 华文楷体; mso-bidi-font-family: +mn-cs; mso-bidi-theme-font: minor-bidi; color: black; mso-color-index: 1; mso-font-kerning: 12.0pt; language: zh-CN; text-combine: letters; font-weight: bold; mso-style-textfill-type: solid; mso-style-textfill-fill-themecolor: text1; mso-style-textfill-fill-color: black; mso-style-textfill-fill-alpha: 100.0%;">氨基甲酰磷酸合成酶（</span><span style=" font-size: 20.0pt; font-family: 华文楷体; mso-ascii-font-family: 华文楷体; mso-fareast-font-family: 华文楷体; mso-bidi-font-family: +mn-cs; mso-bidi-theme-font: minor-bidi; color: red; mso-font-kerning: 12.0pt; language: en-US; text-combine: letters; font-weight: bold; mso-style-textfill-type: solid; mso-style-textfill-fill-color: red; mso-style-textfill-fill-alpha: 100.0%;">CPS-I</span><span style=" font-size: 20.0pt; font-family: 华文楷体; mso-ascii-font-family: 华文楷体; mso-fareast-font-family: 华文楷体; mso-bidi-font-family: +mn-cs; mso-bidi-theme-font: minor-bidi; color: red; mso-font-kerning: 12.0pt; language: zh-CN; text-combine: letters; font-weight: bold; mso-style-textfill-type: solid; mso-style-textfill-fill-color: red; mso-style-textfill-fill-alpha: 100.0%;">，启动限速酶</span><span style=" font-size: 20.0pt; font-family: 华文楷体; mso-ascii-font-family: 华文楷体; mso-fareast-font-family: 华文楷体; mso-bidi-font-family: +mn-cs; mso-bidi-theme-font: minor-bidi; color: black; mso-color-index: 1; mso-font-kerning: 12.0pt; language: en-US; text-combine: letters; font-weight: bold; mso-style-textfill-type: solid; mso-style-textfill-fill-themecolor: text1; mso-style-textfill-fill-color: black; mso-style-textfill-fill-alpha: 100.0%;">)</span><span style=" font-size: 20.0pt; font-family: 华文楷体; mso-ascii-font-family: 华文楷体; mso-fareast-font-family: 华文楷体; mso-bidi-font-family: +mn-cs; mso-bidi-theme-font: minor-bidi; color: black; mso-color-index: 1; mso-font-kerning: 12.0pt; language: zh-CN; text-combine: letters; font-weight: bold; mso-style-textfill-type: solid; mso-style-textfill-fill-themecolor: text1; mso-style-textfill-fill-color: black; mso-style-textfill-fill-alpha: 100.0%;">和精氨酸代琥珀酸合成酶（</span><span style=" font-size: 20.0pt; font-family: 华文楷体; mso-ascii-font-family: 华文楷体; mso-fareast-font-family: 华文楷体; mso-bidi-font-family: +mn-cs; mso-bidi-theme-font: minor-bidi; color: red; mso-font-kerning: 12.0pt; language: en-US; text-combine: letters; font-weight: bold; mso-style-textfill-type: solid; mso-style-textfill-fill-color: red; mso-style-textfill-fill-alpha: 100.0%;">ASS</span><span style=" font-size: 20.0pt; font-family: 华文楷体; mso-ascii-font-family: 华文楷体; mso-fareast-font-family: 华文楷体; mso-bidi-font-family: +mn-cs; mso-bidi-theme-font: minor-bidi; color: red; mso-font-kerning: 12.0pt; language: zh-CN; text-combine: letters; font-weight: bold; mso-style-textfill-type: solid; mso-style-textfill-fill-color: red; mso-style-textfill-fill-alpha: 100.0%;">，启动后的限速酶</span><span style=" font-size: 20.0pt; font-family: 华文楷体; mso-ascii-font-family: 华文楷体; mso-fareast-font-family: 华文楷体; mso-bidi-font-family: +mn-cs; mso-bidi-theme-font: minor-bidi; color: black; mso-color-index: 1; mso-font-kerning: 12.0pt; language: zh-CN; text-combine: letters; font-weight: bold; mso-style-textfill-type: solid; mso-style-textfill-fill-themecolor: text1; mso-style-textfill-fill-color: black; mso-style-textfill-fill-alpha: 100.0%;">）为尿素合成的限速酶。</span></div>

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