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Updated Apr 20, 2026
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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 specifically built for the needs of students. Based on the millions of content pieces we have on the platform we can provide truly meaningful and relevant answers to students. But its not only about answers, the companion is even more about guiding students through their daily learning challenges, with personalised study plans, quizzes or content pieces in the chat and 100% personalisation based on the students skills and developments.
Where can I download the Knowunity app?
You can download the app in the Google Play Store and in the 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
I think it’s very much worth it and you’ll end up using it a lot once you get the hang of it and even after looking at others notes you can still ask your Artificial intelligence buddy the question and ask to simplify it if you still don’t get it!!! In the end I think it’s worth it 😊👍 ⚠️Also DID I MENTION ITS FREEE YOU DON’T HAVE TO PAY FOR ANYTHING AND STILL GET YOUR GRADES IN PERFECTLY❗️❗️⚠️
Thomas R
iOS user
Knowunity is the BEST app I’ve used in a minute. This is not an ai review or anything this is genuinely coming from a 7th grade student (I know 2011 im young) but dude this app is a 10/10 i have maintained a 3.8 gpa and have plenty of time for gaming. I love it and my mom is just happy I got good grades
Brad T
Android user
Not only did it help me find the answer but it also showed me alternative ways to solve it. I was horrible in math and science but now I have an a in both subjects. Thanks for the help🤍🤍
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
I found this app a couple years ago and it has only gotten better since then. I really love it because it can help with written questions and photo questions. Also, it can find study guides that other people have made as well as flashcard sets and practice tests. The free version is also amazing for students who might not be able to afford it. Would 100% recommend
Aubrey
iOS user
Best app if you're in Highschool or Junior high. I have been using this app for 2 school years and it's the best, it's good if you don't have anyone to help you with school work.😋🩷🎀
Marco B
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 app is phenomenal down to the correct info and the various topics you can study! I greatly recommend it for people who struggle with procrastination and those who need homework help. It has been perfectly accurate for world 1 history as far as I’ve seen! Geometry too!
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
I think it’s very much worth it and you’ll end up using it a lot once you get the hang of it and even after looking at others notes you can still ask your Artificial intelligence buddy the question and ask to simplify it if you still don’t get it!!! In the end I think it’s worth it 😊👍 ⚠️Also DID I MENTION ITS FREEE YOU DON’T HAVE TO PAY FOR ANYTHING AND STILL GET YOUR GRADES IN PERFECTLY❗️❗️⚠️
Thomas R
iOS user
Knowunity is the BEST app I’ve used in a minute. This is not an ai review or anything this is genuinely coming from a 7th grade student (I know 2011 im young) but dude this app is a 10/10 i have maintained a 3.8 gpa and have plenty of time for gaming. I love it and my mom is just happy I got good grades
Brad T
Android user
Not only did it help me find the answer but it also showed me alternative ways to solve it. I was horrible in math and science but now I have an a in both subjects. Thanks for the help🤍🤍
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
I found this app a couple years ago and it has only gotten better since then. I really love it because it can help with written questions and photo questions. Also, it can find study guides that other people have made as well as flashcard sets and practice tests. The free version is also amazing for students who might not be able to afford it. Would 100% recommend
Aubrey
iOS user
Best app if you're in Highschool or Junior high. I have been using this app for 2 school years and it's the best, it's good if you don't have anyone to help you with school work.😋🩷🎀
Marco B
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 app is phenomenal down to the correct info and the various topics you can study! I greatly recommend it for people who struggle with procrastination and those who need homework help. It has been perfectly accurate for world 1 history as far as I’ve seen! Geometry too!
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 specifically built for the needs of students. Based on the millions of content pieces we have on the platform we can provide truly meaningful and relevant answers to students. But its not only about answers, the companion is even more about guiding students through their daily learning challenges, with personalised study plans, quizzes or content pieces in the chat and 100% personalisation based on the students skills and developments.
Where can I download the Knowunity app?
You can download the app in the Google Play Store and in the 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.
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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
I think it’s very much worth it and you’ll end up using it a lot once you get the hang of it and even after looking at others notes you can still ask your Artificial intelligence buddy the question and ask to simplify it if you still don’t get it!!! In the end I think it’s worth it 😊👍 ⚠️Also DID I MENTION ITS FREEE YOU DON’T HAVE TO PAY FOR ANYTHING AND STILL GET YOUR GRADES IN PERFECTLY❗️❗️⚠️
Thomas R
iOS user
Knowunity is the BEST app I’ve used in a minute. This is not an ai review or anything this is genuinely coming from a 7th grade student (I know 2011 im young) but dude this app is a 10/10 i have maintained a 3.8 gpa and have plenty of time for gaming. I love it and my mom is just happy I got good grades
Brad T
Android user
Not only did it help me find the answer but it also showed me alternative ways to solve it. I was horrible in math and science but now I have an a in both subjects. Thanks for the help🤍🤍
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
I found this app a couple years ago and it has only gotten better since then. I really love it because it can help with written questions and photo questions. Also, it can find study guides that other people have made as well as flashcard sets and practice tests. The free version is also amazing for students who might not be able to afford it. Would 100% recommend
Aubrey
iOS user
Best app if you're in Highschool or Junior high. I have been using this app for 2 school years and it's the best, it's good if you don't have anyone to help you with school work.😋🩷🎀
Marco B
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 app is phenomenal down to the correct info and the various topics you can study! I greatly recommend it for people who struggle with procrastination and those who need homework help. It has been perfectly accurate for world 1 history as far as I’ve seen! Geometry too!
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
I think it’s very much worth it and you’ll end up using it a lot once you get the hang of it and even after looking at others notes you can still ask your Artificial intelligence buddy the question and ask to simplify it if you still don’t get it!!! In the end I think it’s worth it 😊👍 ⚠️Also DID I MENTION ITS FREEE YOU DON’T HAVE TO PAY FOR ANYTHING AND STILL GET YOUR GRADES IN PERFECTLY❗️❗️⚠️
Thomas R
iOS user
Knowunity is the BEST app I’ve used in a minute. This is not an ai review or anything this is genuinely coming from a 7th grade student (I know 2011 im young) but dude this app is a 10/10 i have maintained a 3.8 gpa and have plenty of time for gaming. I love it and my mom is just happy I got good grades
Brad T
Android user
Not only did it help me find the answer but it also showed me alternative ways to solve it. I was horrible in math and science but now I have an a in both subjects. Thanks for the help🤍🤍
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
I found this app a couple years ago and it has only gotten better since then. I really love it because it can help with written questions and photo questions. Also, it can find study guides that other people have made as well as flashcard sets and practice tests. The free version is also amazing for students who might not be able to afford it. Would 100% recommend
Aubrey
iOS user
Best app if you're in Highschool or Junior high. I have been using this app for 2 school years and it's the best, it's good if you don't have anyone to help you with school work.😋🩷🎀
Marco B
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 app is phenomenal down to the correct info and the various topics you can study! I greatly recommend it for people who struggle with procrastination and those who need homework help. It has been perfectly accurate for world 1 history as far as I’ve seen! Geometry too!
Paul T
iOS user