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Britain & the wider world: 1745 -1901
1l the quest for political stability: germany, 1871-1991
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2d religious conflict and the church in england, c1529-c1570
2o democracy and nazism: germany, 1918-1945
1f industrialisation and the people: britain, c1783-1885
1c the tudors: england, 1485-1603
2m wars and welfare: britain in transition, 1906-1957
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Biology
13 Dec 2025
56
3 pages
Amala Seth @amala_seth
Your immune system has some pretty clever weapons to fight off infections, and antibodies are among the most... Show more
Think of antibodies as your body's personal security team - they're proteins made by special white blood cells called B-lymphocytes. Each antibody is like a highly specialised bouncer that only recognises one specific troublemaker.
The structure is quite brilliant really. Antibodies have a quaternary protein structure made of four chains - two short "light chains" and two longer "heavy chains" all linked together. What makes them so effective is that each antibody has two identical binding sites that perfectly match a specific antigen, like a lock and key.
Here's where it gets interesting for fighting infections. When antibodies find their target bacteria, they cause agglutination - basically clumping the bad guys together. This makes it much easier for your immune system's cleanup crew (phagocytes) to find and destroy them.
Quick Tip The variable region of antibodies changes between different types, whilst the constant region stays the same - this is why each antibody can target different threats whilst still being recognised by your immune system.
Your immune system is incredibly smart - it actually remembers past infections through memory cells. These cells hang around in your body for years, just waiting quietly for their specific enemy to show up again.
When the same pathogen tries to attack you a second time, these memory cells spring into action and divide rapidly. This creates a rapid immune response that destroys the infection before you even feel ill - which is exactly how vaccines work to protect you.
Key Point This is why you usually only get certain illnesses like chickenpox once - your memory cells remember and quickly eliminate the virus before symptoms develop.
Monoclonal antibodies are basically identical copies of one specific antibody type, artificially produced in laboratories. Scientists identify the right B-lymphocyte, then make it divide through mitosis to create loads of identical antibodies.
These lab-made antibodies have some pretty amazing uses in medicine. For cancer treatment, they can be designed to target specific tumour markers, delivering drugs directly to cancer cells whilst leaving healthy cells alone.
You've probably encountered monoclonal antibodies without realising it. Pregnancy tests use antibodies that bind to the hormone hCG - if you're pregnant, the antibodies bind to the hormone and turn the test strip blue.
The ELISA test is another clever application used in medical diagnostics. It works by using antibodies to detect and measure specific proteins in samples. The process involves multiple steps of binding, washing, and adding enzymes that create coloured products - the stronger the colour, the more of the target protein is present.
Real-World Connection ELISA tests are used for everything from detecting food allergies to monitoring hormone levels, making them one of the most versatile diagnostic tools in medicine.
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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Smart Tools NEW
Transform this note into: ✓ 50+ Practice Questions ✓ Interactive Flashcards ✓ Full Mock Exam ✓ Essay Outlines
Explore the ELISA (enzyme-linked immunosorbent assay) testing method, focusing on its application in detecting prostate cancer and HIV antibodies. This summary covers the principles of direct and indirect testing, the role of antibodies, and the significance of color change in results. Ideal for AQA A-Level Biology students studying immunology and biological defenses.
BiologyExplore the intricacies of the specific immune system, covering key concepts such as phagocytes, antibodies, lymphocytes, humoral immunity, and the primary and secondary immune responses. This comprehensive summary is essential for mastering OCR A A-level Biology and understanding autoimmune diseases.
BiologyExplore the key components of the immune system, focusing on B-lymphocytes, antibodies, and physical barriers against pathogens. This summary covers the role of white blood cells in disease prevention and the immune response, essential for understanding immunology in GCSE Biology. Ideal for higher-tier students preparing for exams.
BiologyExplore the adaptive immune response with a focus on antibodies and phagocytosis. This summary covers the structure and function of antibodies, their role in neutralizing pathogens, and the process of phagocytosis by white blood cells. Ideal for AQA A-Level Biology students seeking to understand key concepts in immunology and the immune system.
BiologyExplore the intricate mechanisms of the immune system, focusing on lymphocyte activation, clonal selection, and the roles of T and B cells in both humoral and cell-mediated responses. This summary covers key concepts such as antigen presentation, phagocytosis, and the development of memory cells, essential for AQA A-level Biology students.
BiologyExplore the essential concepts of vaccination, including types of immunity (active, passive, natural, artificial), how vaccines stimulate immune responses, and the importance of herd immunity. This summary provides insights into the ethical considerations surrounding vaccines and their effectiveness against antigenic variability. Ideal for AQA A-level Biology students.
BiologyApp 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
Amala Seth
@amala_seth
Your immune system has some pretty clever weapons to fight off infections, and antibodies are among the most important. These protein molecules act like highly trained detectives, seeking out specific threats and marking them for destruction.
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Think of antibodies as your body's personal security team - they're proteins made by special white blood cells called B-lymphocytes. Each antibody is like a highly specialised bouncer that only recognises one specific troublemaker.
The structure is quite brilliant really. Antibodies have a quaternary protein structure made of four chains - two short "light chains" and two longer "heavy chains" all linked together. What makes them so effective is that each antibody has two identical binding sites that perfectly match a specific antigen, like a lock and key.
Here's where it gets interesting for fighting infections. When antibodies find their target bacteria, they cause agglutination - basically clumping the bad guys together. This makes it much easier for your immune system's cleanup crew (phagocytes) to find and destroy them.
Quick Tip: The variable region of antibodies changes between different types, whilst the constant region stays the same - this is why each antibody can target different threats whilst still being recognised by your immune system.
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Your immune system is incredibly smart - it actually remembers past infections through memory cells. These cells hang around in your body for years, just waiting quietly for their specific enemy to show up again.
When the same pathogen tries to attack you a second time, these memory cells spring into action and divide rapidly. This creates a rapid immune response that destroys the infection before you even feel ill - which is exactly how vaccines work to protect you.
Key Point: This is why you usually only get certain illnesses like chickenpox once - your memory cells remember and quickly eliminate the virus before symptoms develop.
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Monoclonal antibodies are basically identical copies of one specific antibody type, artificially produced in laboratories. Scientists identify the right B-lymphocyte, then make it divide through mitosis to create loads of identical antibodies.
These lab-made antibodies have some pretty amazing uses in medicine. For cancer treatment, they can be designed to target specific tumour markers, delivering drugs directly to cancer cells whilst leaving healthy cells alone.
You've probably encountered monoclonal antibodies without realising it. Pregnancy tests use antibodies that bind to the hormone hCG - if you're pregnant, the antibodies bind to the hormone and turn the test strip blue.
The ELISA test is another clever application used in medical diagnostics. It works by using antibodies to detect and measure specific proteins in samples. The process involves multiple steps of binding, washing, and adding enzymes that create coloured products - the stronger the colour, the more of the target protein is present.
Real-World Connection: ELISA tests are used for everything from detecting food allergies to monitoring hormone levels, making them one of the most versatile diagnostic tools in medicine.
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.
0
Smart Tools NEW
Transform this note into: ✓ 50+ Practice Questions ✓ Interactive Flashcards ✓ Full Mock Exam ✓ Essay Outlines
Explore the ELISA (enzyme-linked immunosorbent assay) testing method, focusing on its application in detecting prostate cancer and HIV antibodies. This summary covers the principles of direct and indirect testing, the role of antibodies, and the significance of color change in results. Ideal for AQA A-Level Biology students studying immunology and biological defenses.
BiologyExplore the intricacies of the specific immune system, covering key concepts such as phagocytes, antibodies, lymphocytes, humoral immunity, and the primary and secondary immune responses. This comprehensive summary is essential for mastering OCR A A-level Biology and understanding autoimmune diseases.
BiologyExplore the key components of the immune system, focusing on B-lymphocytes, antibodies, and physical barriers against pathogens. This summary covers the role of white blood cells in disease prevention and the immune response, essential for understanding immunology in GCSE Biology. Ideal for higher-tier students preparing for exams.
BiologyExplore the adaptive immune response with a focus on antibodies and phagocytosis. This summary covers the structure and function of antibodies, their role in neutralizing pathogens, and the process of phagocytosis by white blood cells. Ideal for AQA A-Level Biology students seeking to understand key concepts in immunology and the immune system.
BiologyExplore the intricate mechanisms of the immune system, focusing on lymphocyte activation, clonal selection, and the roles of T and B cells in both humoral and cell-mediated responses. This summary covers key concepts such as antigen presentation, phagocytosis, and the development of memory cells, essential for AQA A-level Biology students.
BiologyExplore the essential concepts of vaccination, including types of immunity (active, passive, natural, artificial), how vaccines stimulate immune responses, and the importance of herd immunity. This summary provides insights into the ethical considerations surrounding vaccines and their effectiveness against antigenic variability. Ideal for AQA A-level Biology students.
BiologyApp 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
Sociology