心智圖資源庫 原核基因表現調控
原核生物基因表現調控是生物學領域中重要的研究內容,它涉及原核生物如何根據環境條件變化調節其基因表達,以適應不同的生存環境。
編輯於2024-11-01 19:54:23This is a mind map about the annual work plan of the three pillars of human resources. The main contents include: strategic human resources planning, talent recruitment and allocation, employee performance management, employee training and development, employee relationships and communication, employee welfare and care, human resources information system construction, regulatory compliance and risk management, and organizational culture construction.
This is a mind map for the diagnosis and treatment of acute cerebral hemorrhage in patients with hemodialysis. The annual incidence of acute cerebral hemorrhage in patients with hemodialysis is (3.0~10.3)/1000, and the main cause is hypertension. Compared with non-dialysis patients, the most common bleeding site is the basal ganglia area, accounting for 50% to 80%; but the bleeding volume is large and the prognosis is poor, and the mortality rate is 27% to 83%. Especially for patients with hematoma >50ml, hematoma enlarged or ventricular hemorrhage on the second day after onset, the prognosis is very poor.
The logic is clear and the content is rich, covering many aspects of the information technology field. Provides a clear framework and guidance for learning and improving information technology capabilities.
This is a mind map about the annual work plan of the three pillars of human resources. The main contents include: strategic human resources planning, talent recruitment and allocation, employee performance management, employee training and development, employee relationships and communication, employee welfare and care, human resources information system construction, regulatory compliance and risk management, and organizational culture construction.
This is a mind map for the diagnosis and treatment of acute cerebral hemorrhage in patients with hemodialysis. The annual incidence of acute cerebral hemorrhage in patients with hemodialysis is (3.0~10.3)/1000, and the main cause is hypertension. Compared with non-dialysis patients, the most common bleeding site is the basal ganglia area, accounting for 50% to 80%; but the bleeding volume is large and the prognosis is poor, and the mortality rate is 27% to 83%. Especially for patients with hematoma >50ml, hematoma enlarged or ventricular hemorrhage on the second day after onset, the prognosis is very poor.
The logic is clear and the content is rich, covering many aspects of the information technology field. Provides a clear framework and guidance for learning and improving information technology capabilities.
原核基因表現調控
乳糖操縱子與負控誘導系統
lac操縱子中的其他問題
lacA基因及其生理功能
A基因產生的乙醯基轉移酶可以將半乳糖苷乙醯化從而避免被降解產生有害衍生物。
lac基因產物數量上的比較
在一個完全被誘導的細胞中,β⁻半乳糖苷酶、透過酵素及乙醯基轉移酶的拷貝數比例為1:0.5:0.2。
原因:不同的酵素在數量上的差異是由於在翻譯層面上受到調節所致。
調節方式
lac mRNA可能與翻譯過程中的核醣體相脫離,從而終止蛋白質鏈的翻譯。
在lac mRNA分子內部,A基因比Z基因更容易受到內切酶作用而發生降解。
操縱子的融合與基因工程
lac操縱子與負責嘌呤合成的pur操縱子的耦聯
將pur操縱子「嫁接」到lac啟動子上,形成融合基因。
意義:增加蛋白質的合成量。
色氨酸操縱子與負控阻遏系統
特殊代謝物調節活性的類型
可誘導調節:調控分解代謝的操縱子,受cAMP-CRP的調控
可阻遏調控:調控生物合成的操縱子,不受cAMP-CRP的調控。
trp系統就是這種類型
trp操縱子的結構
有7個結構基因,trp的合成分5步驟。
特點
tripR和trpABCDE不連鎖
有弱化子
啟動子和結構基因被前導序列隔開
trp操縱子的阻遏系統
主管轉錄是否起始
調控訊號:trp的多少
trp操縱子的弱化作用
在色氨酸高濃度和低濃度下觀察到trp操縱子的表達量相差600倍,然而阻遏僅使轉錄降低70倍。