Bakterije su svuda oko nas - u vazduhu kojim dišemo,... Show more
Biologija
Srpski jezik
Hemija
Istorija
MatematikaSign up to see the contentIt's free!
Access to all documents
Improve your grades
Join milions of students
291
•
Updated Apr 20, 2026
•
Sve o Bakterijama: Građa, Vrste i Uloga u Prirodi
1 / 5
Šta su bakterije i kako su građene?
Bakterije su jednoćelijski organizmi koji pripadaju grupi prokariota. Ovo je najvažnija reč koju trebaš da zapamtiš! Prokarioti znači da njihova ćelija nema pravo jedro kao što imamo mi.
Glavni delovi bakterijske ćelije su prilično jednostavni. Ćelijski zid im daje oblik i čvrstinu kao neki oklop. Ćelijska membrana kontroliše šta ulazi i izlazi iz ćelije. Citoplazma je tečnost koja ispunjava celu ćeliju.
Najzanimljiviji deo je što njihov nasledni materijal (DNK) slobodno pliva u citoplazmi u delu koji se zove nukleoid. Nema jedra kao kod naših ćelija! Ribozomi prave proteine, a bič služi nekim bakterijama za kretanje kao mali repić.
Zapamti: Glavna razlika između bakterijske i naše ćelije je što bakterije NEMAJU jedro!
Oblici i načini ishrane bakterija
Bakterije dolaze u četiri osnovna oblika, kao da priroda pravi različite oblike testa! Koke su loptaste i mogu biti u grozdovima. Bacili su štapićasti kao mali štapići. Spirile su uvijene kao spirala, a vibrioni su savijeni kao zarez.
Kada je reč o ishrani, bakterije su prave snalažljivice. Autotrofne bakterije same prave hranu - neke koriste sunčevu svetlost poput biljaka, a druge dobijaju energiju iz hemijskih jedinjenja.
Heterotrofne bakterije uzimaju gotovu hranu iz okoline. Saprofiti se hrane ostacima uginulih organizama i čiste prirodu. Paraziti žive na račun drugih organizama i često prave probleme. Simbionti žive u prijateljstvu sa drugim organizmima - kao bakterije u našim crevima koje nam pomažu u varenju.
Zanimljivost: Neke bakterije u tvom cretu proizvode vitamin K koji ti je potreban!
Razmnožavanje i preživljavanje
Bakterije se razmnožavaju prostom deobom - to je kao da se jedna ćelija podeli na pola i nastanu dve identične. Ovaj proces je neverovatno brz! Neke bakterije mogu da se podele na svakih 20 minuta u idealnim uslovima.
Prvo bakterija poraste, zatim se njen DNK udvostruči, pa se cela ćelija podeli na dva jednaka dela. Zato se infekcije mogu tako brzo razviti ako ne pazimo na higijenu.
Kada uslovi postanu teški (suša, visoke temperature), neke pametne bakterije prave sporu. Spora je kao neki otporni "čarobni omotač" koji može da preživi godinama. Čim uslovi postanu bolji, iz spore se razvija aktivna bakterija.
Pametno za test: Razmnožavanje bakterija je UVEK prosta deoba - to je bespolno razmnožavanje!
Korisne i štetne bakterije
Ne veruj filmovima - nisu sve bakterije loše momčice! Mnoge su naši najbolji prijatelji. Korisne bakterije rade mnoge važne poslove: razlažu mrtve organizme i vraćaju hranljive materije u zemljište, pomažu u proizvodnji jogurta i sira, a neke čak prave antibiotike.
Štetne (patogene) bakterije mogu da izazovu probleme. Salmonela pravi trovanje hranom, streptokoke mogu izazvati upalu grla, a bakterije u ustima stvaraju karijes kada razlažu šećer na zubima.
Protiv opasnih bakterija imamo nekoliko oružja. Antibiotici su lekovi koji ubijaju bakterije, ali pazi - deluju samo na bakterije, ne na viruse! Higijena, posebno pranje ruku, je tvoja prva odbrana. Pasterizacija mleka uništava štetne bakterije zagrevanjem.
Važna napomena: Nikad ne mešaj bakterije sa virusima - to su potpuno različite stvari!
Brz pregled za ponavljanje
Evo svega što trebaš da znaš na jednom mestu! Bakterije su prokarioti - jednoćelijski organizmi bez jedra. Njihova građa je jednostavna: ćelijski zid, membrana, citoplazma, nukleoid sa DNK-om i ribozomi.
Postoje četiri osnovna oblika: koke (loptice), bacili (štapići), spirile (spirale) i vibrioni (zarezi). Po ishrani dele se na autotrofe (prave hranu) i heterotrofe (uzimaju gotovu hranu iz okoline).
Razmnožavanje je prosta deoba koja može biti veoma brza. Korisne bakterije nam pomažu u proizvodnji hrane i čišćenju prirode. Štetne mogu izazvati bolesti, ali protiv njih imamo antibiotike i higijenu. Zapamti da antibiotici deluju samo na bakterije, ne na viruse!
Za odličnu ocenu: Uvek navedi konkretne primere korisnih i štetnih bakterija!
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 in Biologija
Most popular content
Can't find what you're looking for? Explore other subjects.
Students love us — and so will you.
4.6/5
App Store
4.7/5
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 Knowunity AI. 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 Knowunity AI. 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
Sve o Bakterijama: Građa, Vrste i Uloga u Prirodi
Bakterije su svuda oko nas - u vazduhu kojim dišemo, hrani koju jedemo, pa čak i u našem telu! Ovi sitni jednoćelijski organizmi su najjednostavniji, ali i najvažniji živi bića na planeti. Nisu sve bakterije loše - mnoge su naši... Show more
Šta su bakterije i kako su građene?
Bakterije su jednoćelijski organizmi koji pripadaju grupi prokariota. Ovo je najvažnija reč koju trebaš da zapamtiš! Prokarioti znači da njihova ćelija nema pravo jedro kao što imamo mi.
Glavni delovi bakterijske ćelije su prilično jednostavni. Ćelijski zid im daje oblik i čvrstinu kao neki oklop. Ćelijska membrana kontroliše šta ulazi i izlazi iz ćelije. Citoplazma je tečnost koja ispunjava celu ćeliju.
Najzanimljiviji deo je što njihov nasledni materijal (DNK) slobodno pliva u citoplazmi u delu koji se zove nukleoid. Nema jedra kao kod naših ćelija! Ribozomi prave proteine, a bič služi nekim bakterijama za kretanje kao mali repić.
Zapamti: Glavna razlika između bakterijske i naše ćelije je što bakterije NEMAJU jedro!
Sign up to see the contentIt's free!
Access to all documents
Improve your grades
Join milions of students
Oblici i načini ishrane bakterija
Bakterije dolaze u četiri osnovna oblika, kao da priroda pravi različite oblike testa! Koke su loptaste i mogu biti u grozdovima. Bacili su štapićasti kao mali štapići. Spirile su uvijene kao spirala, a vibrioni su savijeni kao zarez.
Kada je reč o ishrani, bakterije su prave snalažljivice. Autotrofne bakterije same prave hranu - neke koriste sunčevu svetlost poput biljaka, a druge dobijaju energiju iz hemijskih jedinjenja.
Heterotrofne bakterije uzimaju gotovu hranu iz okoline. Saprofiti se hrane ostacima uginulih organizama i čiste prirodu. Paraziti žive na račun drugih organizama i često prave probleme. Simbionti žive u prijateljstvu sa drugim organizmima - kao bakterije u našim crevima koje nam pomažu u varenju.
Zanimljivost: Neke bakterije u tvom cretu proizvode vitamin K koji ti je potreban!
Sign up to see the contentIt's free!
Access to all documents
Improve your grades
Join milions of students
Razmnožavanje i preživljavanje
Bakterije se razmnožavaju prostom deobom - to je kao da se jedna ćelija podeli na pola i nastanu dve identične. Ovaj proces je neverovatno brz! Neke bakterije mogu da se podele na svakih 20 minuta u idealnim uslovima.
Prvo bakterija poraste, zatim se njen DNK udvostruči, pa se cela ćelija podeli na dva jednaka dela. Zato se infekcije mogu tako brzo razviti ako ne pazimo na higijenu.
Kada uslovi postanu teški (suša, visoke temperature), neke pametne bakterije prave sporu. Spora je kao neki otporni "čarobni omotač" koji može da preživi godinama. Čim uslovi postanu bolji, iz spore se razvija aktivna bakterija.
Pametno za test: Razmnožavanje bakterija je UVEK prosta deoba - to je bespolno razmnožavanje!
Sign up to see the contentIt's free!
Access to all documents
Improve your grades
Join milions of students
Korisne i štetne bakterije
Ne veruj filmovima - nisu sve bakterije loše momčice! Mnoge su naši najbolji prijatelji. Korisne bakterije rade mnoge važne poslove: razlažu mrtve organizme i vraćaju hranljive materije u zemljište, pomažu u proizvodnji jogurta i sira, a neke čak prave antibiotike.
Štetne (patogene) bakterije mogu da izazovu probleme. Salmonela pravi trovanje hranom, streptokoke mogu izazvati upalu grla, a bakterije u ustima stvaraju karijes kada razlažu šećer na zubima.
Protiv opasnih bakterija imamo nekoliko oružja. Antibiotici su lekovi koji ubijaju bakterije, ali pazi - deluju samo na bakterije, ne na viruse! Higijena, posebno pranje ruku, je tvoja prva odbrana. Pasterizacija mleka uništava štetne bakterije zagrevanjem.
Važna napomena: Nikad ne mešaj bakterije sa virusima - to su potpuno različite stvari!
Sign up to see the contentIt's free!
Access to all documents
Improve your grades
Join milions of students
Brz pregled za ponavljanje
Evo svega što trebaš da znaš na jednom mestu! Bakterije su prokarioti - jednoćelijski organizmi bez jedra. Njihova građa je jednostavna: ćelijski zid, membrana, citoplazma, nukleoid sa DNK-om i ribozomi.
Postoje četiri osnovna oblika: koke (loptice), bacili (štapići), spirile (spirale) i vibrioni (zarezi). Po ishrani dele se na autotrofe (prave hranu) i heterotrofe (uzimaju gotovu hranu iz okoline).
Razmnožavanje je prosta deoba koja može biti veoma brza. Korisne bakterije nam pomažu u proizvodnji hrane i čišćenju prirode. Štetne mogu izazvati bolesti, ali protiv njih imamo antibiotike i higijenu. Zapamti da antibiotici deluju samo na bakterije, ne na viruse!
Za odličnu ocenu: Uvek navedi konkretne primere korisnih i štetnih bakterija!
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.
8
Smart Tools NEW
Transform this note into: ✓ 50+ Practice Questions ✓ Interactive Flashcards ✓ Full Mock Exam ✓ Essay Outlines
Mock Exam
Quiz
Flashcards
Essay
Most popular content in Biologija
Most popular content
Can't find what you're looking for? Explore other subjects.
Students love us — and so will you.
4.6/5
App Store
4.7/5
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 Knowunity AI. 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 Knowunity AI. 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