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Aasiyah Rahman
17/12/2025
Biology
Digestion and Absorption- Enzymes and Thier location
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17 Dec 2025
•
How Digestion Works: Enzymes and Absorption Locations
Aasiyah Rahman
@aasiyahrahman
1 / 9
Why We Need Digestion
Think about it - that sandwich you had for lunch contains massive molecules that are way too big to squeeze through your intestinal walls. Polymers (large molecules) need to be broken down into monomers (small molecules) so they can actually get into your blood and feed your cells.
Your body uses three main types of enzymes to tackle different foods. Amylase breaks down carbohydrates, lipase handles fats, and various peptidases deal with proteins.
Carbohydrate digestion starts with amylase attacking starch. This enzyme is produced in your pancreas, small intestine, and even your salivary glands - that's why bread starts tasting sweet if you chew it long enough! Amylase breaks the bonds in starch to produce maltose.
Quick Tip: Remember that digestion is all about breaking bonds - think of enzymes as molecular scissors cutting up your food!
The final step happens with disaccharidases - special enzymes stuck to the walls of your small intestine. These break down disaccharides like maltose, sucrose, and lactose into simple sugars your body can absorb.
Fat Digestion - It's All About Surface Area
Fats are tricky to digest because they don't mix with water. Lipase enzymes from your pancreas break down triglycerides by chopping up their ester bonds, producing one monoglyceride and two fatty acids.
But here's where it gets clever - your liver produces bile salts that don't actually digest fats but make the job much easier. Think of bile salts as biological detergent.
Emulsification is the key process here. Bile salts break large fat globules into tiny droplets, massively increasing the surface area for lipase to work on.
Remember: Bile salts don't digest - they just make fat droplets smaller so lipase can work more efficiently!
After digestion, something brilliant happens. The fatty acids and monoglycerides stick to bile salts forming micelles - tiny transport vehicles that carry the digested fats to your intestinal wall for absorption.
Protein Digestion - Tag Team Approach
Proteins are tough customers, so your body uses a tag team of different peptidases (also called proteases) to break them down completely. Each enzyme targets different bonds in the protein chain.
Endopeptidases are the heavy hitters - they attack bonds in the middle of protein chains. You've got trypsin and chymotrypsin from your pancreas working in the small intestine, plus pepsin doing the dirty work in your acidic stomach.
Exopeptidases clean up by attacking bonds at the ends of protein fragments. They're like the finishing crew, nibbling away at the edges.
Top Tip: Think endo = inside, exo = outside to remember where these enzymes work on proteins!
Finally, dipeptidases handle the last stage. These specialised enzymes, often attached to your intestinal wall, break apart the final two-amino-acid fragments into individual amino acids ready for absorption.
Getting Nutrients Into Your Blood
Once everything's broken down, the real challenge begins - getting these nutrients through your intestinal wall and into your bloodstream. Your small intestine has some clever transport systems to make this happen.
Glucose and galactose use co-transport with sodium ions. Your intestinal cells actively pump sodium out, creating a concentration gradient that pulls sodium back in - and glucose hitches a ride through special transporter proteins.
Fructose takes a different route, using facilitated diffusion through its own special transporter proteins.
Key Point: Different sugars use different transport methods - that's why your body can absorb multiple types simultaneously!
Amino acids also use the sodium co-transport system, riding along with sodium ions as they flow back into intestinal cells. Meanwhile, fatty acids and monoglycerides simply diffuse through cell membranes because they're fat-soluble - no special transport needed!
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Basil
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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
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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!
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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.
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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
How Digestion Works: Enzymes and Absorption Locations
Aasiyah Rahman
@aasiyahrahman
Your digestive system is like a massive food processing plant, breaking down everything you eat into tiny molecules your body can actually use. This happens through digestion- where special enzymes chop up large food molecules into smaller pieces that... Show more
Why We Need Digestion
Think about it - that sandwich you had for lunch contains massive molecules that are way too big to squeeze through your intestinal walls. Polymers (large molecules) need to be broken down into monomers (small molecules) so they can actually get into your blood and feed your cells.
Your body uses three main types of enzymes to tackle different foods. Amylase breaks down carbohydrates, lipase handles fats, and various peptidases deal with proteins.
Carbohydrate digestion starts with amylase attacking starch. This enzyme is produced in your pancreas, small intestine, and even your salivary glands - that's why bread starts tasting sweet if you chew it long enough! Amylase breaks the bonds in starch to produce maltose.
Quick Tip: Remember that digestion is all about breaking bonds - think of enzymes as molecular scissors cutting up your food!
The final step happens with disaccharidases - special enzymes stuck to the walls of your small intestine. These break down disaccharides like maltose, sucrose, and lactose into simple sugars your body can absorb.
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Fat Digestion - It's All About Surface Area
Fats are tricky to digest because they don't mix with water. Lipase enzymes from your pancreas break down triglycerides by chopping up their ester bonds, producing one monoglyceride and two fatty acids.
But here's where it gets clever - your liver produces bile salts that don't actually digest fats but make the job much easier. Think of bile salts as biological detergent.
Emulsification is the key process here. Bile salts break large fat globules into tiny droplets, massively increasing the surface area for lipase to work on.
Remember: Bile salts don't digest - they just make fat droplets smaller so lipase can work more efficiently!
After digestion, something brilliant happens. The fatty acids and monoglycerides stick to bile salts forming micelles - tiny transport vehicles that carry the digested fats to your intestinal wall for absorption.
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
Protein Digestion - Tag Team Approach
Proteins are tough customers, so your body uses a tag team of different peptidases (also called proteases) to break them down completely. Each enzyme targets different bonds in the protein chain.
Endopeptidases are the heavy hitters - they attack bonds in the middle of protein chains. You've got trypsin and chymotrypsin from your pancreas working in the small intestine, plus pepsin doing the dirty work in your acidic stomach.
Exopeptidases clean up by attacking bonds at the ends of protein fragments. They're like the finishing crew, nibbling away at the edges.
Top Tip: Think endo = inside, exo = outside to remember where these enzymes work on proteins!
Finally, dipeptidases handle the last stage. These specialised enzymes, often attached to your intestinal wall, break apart the final two-amino-acid fragments into individual amino acids ready for absorption.
Sign up to see the contentIt's free!
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Improve your grades
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Getting Nutrients Into Your Blood
Once everything's broken down, the real challenge begins - getting these nutrients through your intestinal wall and into your bloodstream. Your small intestine has some clever transport systems to make this happen.
Glucose and galactose use co-transport with sodium ions. Your intestinal cells actively pump sodium out, creating a concentration gradient that pulls sodium back in - and glucose hitches a ride through special transporter proteins.
Fructose takes a different route, using facilitated diffusion through its own special transporter proteins.
Key Point: Different sugars use different transport methods - that's why your body can absorb multiple types simultaneously!
Amino acids also use the sodium co-transport system, riding along with sodium ions as they flow back into intestinal cells. Meanwhile, fatty acids and monoglycerides simply diffuse through cell membranes because they're fat-soluble - no special transport needed!
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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?
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Is Knowunity really free of charge?
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Most popular content: Digestive System
Most popular content in Biology
Most popular content
English - inspector calls quotes and analysis
Quotes from every main character
English Literature10
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