Ever wondered what's actually happening inside your cells right now?... Show more
Biología
English Literature
SociologySign up to see the contentIt's free!
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
82
•
23 Dec 2025
•
GCSE Biology: Exploring B1.2 Concepts
Jessica Howard
@jessicahoward_cgbh
Essential Cell Components and Processes
DNA is the star of the show - it's the molecule that stores all your genetic information and forms the main part of chromosomes. Picture it as a twisted ladder called a double helix, where two parallel strands wind around each other. The rungs of this ladder are made through complementary base pairing - adenine always pairs with thymine, and guanine always pairs with cytosine.
The building blocks of DNA are called nucleotides, which are like molecular Lego pieces. Each nucleotide contains three parts: an organic base (the letters A, T, G, or C), a sugar, and a phosphate group. When something goes wrong and the structure of a gene changes, that's called a mutation.
Enzymes are your cell's superheroes - they're biological catalysts that speed up reactions without getting used up themselves. Think of the lock and key model: each enzyme has a specific active site where substrate molecules fit perfectly, just like a key fits into its matching lock. This is why we say enzymes have enzyme specificity - they're picky about which reactions they'll help with!
Quick Tip: Remember that enzymes are made of amino acids - the small building blocks that link together to form proteins. Everything in biology is connected!
How Cells Make Proteins and Control Reactions
Protein synthesis is how your cells make the proteins you need to survive, and it happens in two main stages. First, transcription copies DNA into mRNA (messenger RNA) in the nucleus. Then, translation takes that mRNA to the ribosomes, where amino acids are joined together using the triplet code - every three letters of mRNA code for one amino acid.
Understanding reaction rates is crucial for biology exams. The initial rate is how fast a reaction starts, and you can measure this by drawing a tangent line on a graph. Several factors affect how fast enzymes work: temperature (thermal energy), pH , enzyme concentration, and substrate concentration.
Sometimes reactions slow down or stop because of a limiting factor - think of it as a bottleneck that prevents the reaction from going faster. This could be running out of substrate, having too few enzymes, or conditions being too hot or cold.
Remember that biological molecules are often polymers - large molecules made by joining many monomers (smaller units) together. DNA is a polymer of nucleotides, and proteins are polymers of amino acids!
Exam Success: Practice drawing enzyme graphs and identifying limiting factors - these questions come up frequently and are easy marks once you understand the patterns!
We thought you’d never ask...
What is the Knowunity AI companion?
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.
Where can I download the Knowunity app?
You can download the app from Google Play Store and Apple App Store.
Is Knowunity really free of charge?
That's right! Enjoy free access to study content, connect with fellow students, and get instant help – all at your fingertips.
Most popular content: Enzymes
Most popular content in Biology
Most popular content
Can't find what you're looking for? Explore other subjects.
Students love us — and so will you.
4.9/5
App Store
4.8/5
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
GCSE Biology: Exploring B1.2 Concepts
Jessica Howard
@jessicahoward_cgbh
Ever wondered what's actually happening inside your cells right now? From enzymes speeding up reactions to DNA storing your genetic blueprint, cells are like tiny factories working non-stop to keep you alive. Let's break down the essential vocabulary you need... Show more
Essential Cell Components and Processes
DNA is the star of the show - it's the molecule that stores all your genetic information and forms the main part of chromosomes. Picture it as a twisted ladder called a double helix, where two parallel strands wind around each other. The rungs of this ladder are made through complementary base pairing - adenine always pairs with thymine, and guanine always pairs with cytosine.
The building blocks of DNA are called nucleotides, which are like molecular Lego pieces. Each nucleotide contains three parts: an organic base (the letters A, T, G, or C), a sugar, and a phosphate group. When something goes wrong and the structure of a gene changes, that's called a mutation.
Enzymes are your cell's superheroes - they're biological catalysts that speed up reactions without getting used up themselves. Think of the lock and key model: each enzyme has a specific active site where substrate molecules fit perfectly, just like a key fits into its matching lock. This is why we say enzymes have enzyme specificity - they're picky about which reactions they'll help with!
Quick Tip: Remember that enzymes are made of amino acids - the small building blocks that link together to form proteins. Everything in biology is connected!
Sign up to see the contentIt's free!
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
How Cells Make Proteins and Control Reactions
Protein synthesis is how your cells make the proteins you need to survive, and it happens in two main stages. First, transcription copies DNA into mRNA (messenger RNA) in the nucleus. Then, translation takes that mRNA to the ribosomes, where amino acids are joined together using the triplet code - every three letters of mRNA code for one amino acid.
Understanding reaction rates is crucial for biology exams. The initial rate is how fast a reaction starts, and you can measure this by drawing a tangent line on a graph. Several factors affect how fast enzymes work: temperature (thermal energy), pH , enzyme concentration, and substrate concentration.
Sometimes reactions slow down or stop because of a limiting factor - think of it as a bottleneck that prevents the reaction from going faster. This could be running out of substrate, having too few enzymes, or conditions being too hot or cold.
Remember that biological molecules are often polymers - large molecules made by joining many monomers (smaller units) together. DNA is a polymer of nucleotides, and proteins are polymers of amino acids!
Exam Success: Practice drawing enzyme graphs and identifying limiting factors - these questions come up frequently and are easy marks once you understand the patterns!
We thought you’d never ask...
What is the Knowunity AI companion?
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.
Where can I download the Knowunity app?
You can download the app from Google Play Store and Apple App Store.
Is Knowunity really free of charge?
That's right! Enjoy free access to study content, connect with fellow students, and get instant help – all at your fingertips.
2
Smart Tools NEW
Transform this note into: ✓ 50+ Practice Questions ✓ Interactive Flashcards ✓ Full Mock Exam ✓ Essay Outlines
Mock Exam
Quiz
Flashcards
Essay
Similar content
Bioenergetics Overview
Explore the essential concepts of bioenergetics, including photosynthesis, cellular respiration, and the factors influencing plant growth. This summary covers the processes of energy transformation in living organisms, the role of light intensity, temperature, and carbon dioxide in photosynthesis, and the significance of aerobic and anaerobic respiration. Ideal for students studying biological life processes and cellular metabolism.
Biology9
Enzyme Function & Kinetics
Explore the mechanisms of enzyme action, including the induced fit model, lock and key theory, and factors affecting enzyme activity such as temperature and pH. This summary covers key concepts in enzyme kinetics, including how to calculate reaction rates and the role of enzymes in biological processes. Ideal for GCSE Biology students.
Biology11
Calvin Cycle Overview
Explore the Calvin Cycle, the light-independent reactions of photosynthesis occurring in the stroma. This summary covers the journey of carbon dioxide, the role of RuBISCO, ATP and NADPH in synthesizing glucose, and the regeneration of RuBP. Ideal for students studying photosynthesis and its biochemical processes.
Biology12
Photosynthesis Mechanisms Explained
Explore the intricate processes of photosynthesis, focusing on the light-dependent and light-independent reactions. This summary covers key concepts such as chloroplast structure, the role of chlorophyll, photolysis, ATP production, and the Calvin cycle. Ideal for A Level Biology students seeking a comprehensive understanding of photosynthesis.
Biology12
Cellular Respiration Overview
Explore the key processes of cellular respiration, including glycolysis, the Krebs cycle, and oxidative phosphorylation. This summary highlights ATP production, metabolic pathways, and the role of NADH and FADH2 in energy transfer. Ideal for A2 Level WJEC biology students.
Biology13
Photosynthesis Mechanisms Explained
Explore the intricate processes of photosynthesis, including light-dependent and light-independent reactions, chloroplast structure, and the role of pigments like chlorophyll. This summary covers key concepts such as thylakoids, the Calvin cycle, and the action spectrum, providing a comprehensive overview for A-level Biology students.
Biology12
Most popular content: Enzymes
Most popular content in Biology
Most popular content
Can't find what you're looking for? Explore other subjects.
Students love us — and so will you.
4.9/5
App Store
4.8/5
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