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8
0
Control of genetic expression
320
•
6 Jan 2023
•
Diya Shah
@diyashah583
Gene expression control in prokaryotes and eukaryotes involves complex mechanisms... Show more
Operons are sections of DNA found in prokaryotes that contain a cluster of structural genes transcribed together. These genes typically code for useful proteins such as enzymes. An operon consists of several key elements:
The lac operon, found in E. coli, is a classic example of an operon system. It controls the expression of genes necessary for lactose metabolism when glucose is unavailable.
Example: The lac operon in E. coli contains three structural genes: lac Z, lac Y, and lac A, which produce proteins that help bacteria digest lactose.
When lactose is absent, the lac repressor binds to the operator site, blocking transcription. When lactose is present, it binds to the repressor, changing its shape and allowing RNA polymerase to begin transcription of the structural genes.
Highlight: The lac operon demonstrates how prokaryotes can efficiently regulate gene expression in response to environmental changes.
Post-transcriptional modifications also play a role in gene expression control. For example, when mRNA is first made , it contains both exons and introns. Through a process called splicing, introns are removed, and exons are joined together to produce mature mRNA.
Post-transcriptional modifications are crucial in refining gene expression control. These modifications occur after the initial transcription of DNA into RNA and include:
Definition: RNA splicing is the process of removing introns and joining exons to produce mature mRNA.
The 5' cap and 3' poly tail serve important functions:
Post-translational modifications also play a significant role in gene expression control. One of the most important post-translational adaptations is phosphorylation.
Highlight: Phosphorylation activates or deactivates nearly half of all enzymes, making it a crucial mechanism for regulating protein function.
For example, cAMP activates an enzyme called PKA , which in turn activates other enzymes by adding a phosphate group. This process is involved in various cellular functions, including:
Example: The activation of PKA by cAMP demonstrates how post-translational modifications can create a cascade of effects, amplifying the initial signal and leading to significant changes in cellular function.
These various levels of control – transcriptional, post-transcriptional, and post-translational – allow for precise regulation of gene expression, enabling cells to respond efficiently to their environment and maintain proper function.
Regulation of gene expression is a fundamental process in both prokaryotes and eukaryotes. All cells carry the same genes, but not all genes are expressed in every cell. This differential gene expression is controlled at both transcriptional and translational levels.
Transcription factors play a crucial role in controlling gene expression. These proteins bind to DNA and can switch genes on or off by altering the rate of transcription. An increase in transcription leads to increased mRNA production, which in turn results in increased protein production.
Vocabulary: Transcription factors are proteins made by regulatory genes that bind to specific DNA sequences to control gene expression.
The structure of genes includes both coding regions and non-coding regions . At the start of each gene, there is a promoter region, which contains a sequence called the TATA box.
Definition: The TATA box is a binding site near the start of the promoter sequence where transcription factors can attach.
In eukaryotes, transcription factors bind to specific DNA sites near the start of their target genes. In prokaryotes, gene expression control often involves transcription factors binding to operons.
Highlight: The difference in gene expression control between eukaryotes and prokaryotes reflects their different cellular organizations and needs.
Our AI Companion is a student-focused AI tool that offers more than just answers. Built on millions of Knowunity resources, it provides relevant information, personalised study plans, quizzes, and content directly in the chat, adapting to your individual learning journey.
You can download the app from Google Play Store and Apple App Store.
That's right! Enjoy free access to study content, connect with fellow students, and get instant help – all at your fingertips.
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The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
Best app on earth! no words because it’s too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
Best app on earth! no words because it’s too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user
Diya Shah
@diyashah583
Gene expression control in prokaryotes and eukaryotes involves complex mechanisms at transcriptional and post-transcriptional levels. Transcription factors play a crucial role in regulating gene expression by binding to specific DNA sequences. In prokaryotes, operons like the lac operoncontrol gene... Show more
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Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Operons are sections of DNA found in prokaryotes that contain a cluster of structural genes transcribed together. These genes typically code for useful proteins such as enzymes. An operon consists of several key elements:
The lac operon, found in E. coli, is a classic example of an operon system. It controls the expression of genes necessary for lactose metabolism when glucose is unavailable.
Example: The lac operon in E. coli contains three structural genes: lac Z, lac Y, and lac A, which produce proteins that help bacteria digest lactose.
When lactose is absent, the lac repressor binds to the operator site, blocking transcription. When lactose is present, it binds to the repressor, changing its shape and allowing RNA polymerase to begin transcription of the structural genes.
Highlight: The lac operon demonstrates how prokaryotes can efficiently regulate gene expression in response to environmental changes.
Post-transcriptional modifications also play a role in gene expression control. For example, when mRNA is first made , it contains both exons and introns. Through a process called splicing, introns are removed, and exons are joined together to produce mature mRNA.
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Post-transcriptional modifications are crucial in refining gene expression control. These modifications occur after the initial transcription of DNA into RNA and include:
Definition: RNA splicing is the process of removing introns and joining exons to produce mature mRNA.
The 5' cap and 3' poly tail serve important functions:
Post-translational modifications also play a significant role in gene expression control. One of the most important post-translational adaptations is phosphorylation.
Highlight: Phosphorylation activates or deactivates nearly half of all enzymes, making it a crucial mechanism for regulating protein function.
For example, cAMP activates an enzyme called PKA , which in turn activates other enzymes by adding a phosphate group. This process is involved in various cellular functions, including:
Example: The activation of PKA by cAMP demonstrates how post-translational modifications can create a cascade of effects, amplifying the initial signal and leading to significant changes in cellular function.
These various levels of control – transcriptional, post-transcriptional, and post-translational – allow for precise regulation of gene expression, enabling cells to respond efficiently to their environment and maintain proper function.
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Regulation of gene expression is a fundamental process in both prokaryotes and eukaryotes. All cells carry the same genes, but not all genes are expressed in every cell. This differential gene expression is controlled at both transcriptional and translational levels.
Transcription factors play a crucial role in controlling gene expression. These proteins bind to DNA and can switch genes on or off by altering the rate of transcription. An increase in transcription leads to increased mRNA production, which in turn results in increased protein production.
Vocabulary: Transcription factors are proteins made by regulatory genes that bind to specific DNA sequences to control gene expression.
The structure of genes includes both coding regions and non-coding regions . At the start of each gene, there is a promoter region, which contains a sequence called the TATA box.
Definition: The TATA box is a binding site near the start of the promoter sequence where transcription factors can attach.
In eukaryotes, transcription factors bind to specific DNA sites near the start of their target genes. In prokaryotes, gene expression control often involves transcription factors binding to operons.
Highlight: The difference in gene expression control between eukaryotes and prokaryotes reflects their different cellular organizations and needs.
Our AI Companion is a student-focused AI tool that offers more than just answers. Built on millions of Knowunity resources, it provides relevant information, personalised study plans, quizzes, and content directly in the chat, adapting to your individual learning journey.
You can download the app from Google Play Store and Apple App Store.
That's right! Enjoy free access to study content, connect with fellow students, and get instant help – all at your fingertips.
App Store
Google Play
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
Best app on earth! no words because it’s too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
Best app on earth! no words because it’s too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user
