outline 3 iii.control of gene expression in prokaryotes a. regulatory proteins b. the operon model...
TRANSCRIPT
![Page 1: OUTLINE 3 III.Control of Gene Expression in Prokaryotes A. Regulatory proteins B. The operon model C. Examples 1. the lac operon (substrate induction)](https://reader036.vdocuments.site/reader036/viewer/2022082505/56649d195503460f949ee7e0/html5/thumbnails/1.jpg)
OUTLINE 3
III. Control of Gene Expression in Prokaryotes
A. Regulatory proteins
B. The operon model
C. Examples
1. the lac operon (substrate induction)2. the tryp operon (end product repression)3. the lac operon (positive control)
![Page 2: OUTLINE 3 III.Control of Gene Expression in Prokaryotes A. Regulatory proteins B. The operon model C. Examples 1. the lac operon (substrate induction)](https://reader036.vdocuments.site/reader036/viewer/2022082505/56649d195503460f949ee7e0/html5/thumbnails/2.jpg)
![Page 3: OUTLINE 3 III.Control of Gene Expression in Prokaryotes A. Regulatory proteins B. The operon model C. Examples 1. the lac operon (substrate induction)](https://reader036.vdocuments.site/reader036/viewer/2022082505/56649d195503460f949ee7e0/html5/thumbnails/3.jpg)
Fig. 18.21
Negative regulation:Substrate induction
![Page 4: OUTLINE 3 III.Control of Gene Expression in Prokaryotes A. Regulatory proteins B. The operon model C. Examples 1. the lac operon (substrate induction)](https://reader036.vdocuments.site/reader036/viewer/2022082505/56649d195503460f949ee7e0/html5/thumbnails/4.jpg)
Fig. 18.22aPositive regulation of the lac operon
![Page 5: OUTLINE 3 III.Control of Gene Expression in Prokaryotes A. Regulatory proteins B. The operon model C. Examples 1. the lac operon (substrate induction)](https://reader036.vdocuments.site/reader036/viewer/2022082505/56649d195503460f949ee7e0/html5/thumbnails/5.jpg)
Fig. 18.22bPositive regulation of the lac operon
![Page 6: OUTLINE 3 III.Control of Gene Expression in Prokaryotes A. Regulatory proteins B. The operon model C. Examples 1. the lac operon (substrate induction)](https://reader036.vdocuments.site/reader036/viewer/2022082505/56649d195503460f949ee7e0/html5/thumbnails/6.jpg)
Lac Operon
No food• Glucose?
• Lactose?
• Low: cAMP high, CRP attaches
• Low: Repressor attached
Operon is ready to be enhanced but is shut off
![Page 7: OUTLINE 3 III.Control of Gene Expression in Prokaryotes A. Regulatory proteins B. The operon model C. Examples 1. the lac operon (substrate induction)](https://reader036.vdocuments.site/reader036/viewer/2022082505/56649d195503460f949ee7e0/html5/thumbnails/7.jpg)
Lac Operon
Milk• Glucose?
• Lactose?
• Low: cAMP high, CRP attaches
• High: Repressor removed
Operon is on and enhanced
![Page 8: OUTLINE 3 III.Control of Gene Expression in Prokaryotes A. Regulatory proteins B. The operon model C. Examples 1. the lac operon (substrate induction)](https://reader036.vdocuments.site/reader036/viewer/2022082505/56649d195503460f949ee7e0/html5/thumbnails/8.jpg)
Lac Operon
Milkshake• Glucose?
• Lactose?
• High: cAMP low, CRP off
• Low: Repressor removed
Operon is on but un-enhanced
![Page 9: OUTLINE 3 III.Control of Gene Expression in Prokaryotes A. Regulatory proteins B. The operon model C. Examples 1. the lac operon (substrate induction)](https://reader036.vdocuments.site/reader036/viewer/2022082505/56649d195503460f949ee7e0/html5/thumbnails/9.jpg)
Lac Operon
Powerade• Glucose?
• Lactose?
• High: cAMP low, CRP off
• Low: Repressor attached
Operon is off and un-enhanced
![Page 10: OUTLINE 3 III.Control of Gene Expression in Prokaryotes A. Regulatory proteins B. The operon model C. Examples 1. the lac operon (substrate induction)](https://reader036.vdocuments.site/reader036/viewer/2022082505/56649d195503460f949ee7e0/html5/thumbnails/10.jpg)
Lac Operon
• No food: ready to be enhanced but off
• Milk: enhanced transcription
• Milkshake: un-enhanced transcription
• Powerade: off and un-enhanced
![Page 11: OUTLINE 3 III.Control of Gene Expression in Prokaryotes A. Regulatory proteins B. The operon model C. Examples 1. the lac operon (substrate induction)](https://reader036.vdocuments.site/reader036/viewer/2022082505/56649d195503460f949ee7e0/html5/thumbnails/11.jpg)
Fig 18.20Negative regulation: end-product repression