Це відео не доступне.
Перепрошуємо.
Structures Present in Bacteria And their Functions | Prokaryotes |
Вставка
- Опубліковано 23 січ 2022
- A key feature of nearly all prokaryotic cells is the cell wall, which maintains cell shape, protects the cell, and prevents it from bursting in a hypotonic environment.
The cell walls of prokaryotes differ in structure from those of eukaryotes. In eukaryotes that have cell walls, such as plants and fungi, the walls are usually made of cellulose or chitin. In contrast, most bacterial cell walls contain peptidoglycan, a polymer composed of modified sugars cross-linked by short polypeptides.
Using a technique called the Gram stain, developed by the 19th-century Danish physician Hans Christian Gram, scientists can categorize many bacterial species according to differences in cell wall composition.
Gram-positive bacteria have simpler walls with a relatively large amount of peptidoglycan. Gram-negative bacteria have less peptidoglycan
and are structurally more complex, with an outer membrane
that contains lipopolysaccharides (carbohydrates bonded
to lipids).
The cell wall of many prokaryotes is surrounded by a sticky layer of polysaccharide or protein. This layer is called a capsule.
In another way of withstanding harsh conditions, certain bacteria develop resistant cells called endospores when they lack an essential nutrient. The original cell produces a copy of its chromosome and surrounds that copy
with a tough multilayered structure, forming the endospore. some prokaryotes stick to their substrate or to one another by means of hair like appendages called fimbriae (singular, fimbria) Fimbriae are usually shorter and more numerous than pili (singular, pilus), appendages that
pull two cells together prior to DNA transfer from one cell to the other.
pili are sometimes referred to as sex pili.
About half of all prokaryotes are capable of taxis, a directed movement toward or away from a stimulus. For example, prokaryotes that exhibit chemotaxis change their movement pattern in response to chemicals. They may move toward nutrients or oxygen (positive chemotaxis) or away from a toxic substance (negative chemotaxis).
The bacterial flagellum has three main parts (the motor, hook, and filament) that are themselves composed of 42 different kinds of proteins.
The cells of prokaryotes are simpler than those of eukaryotes
in both their internal structure and the physical arrangement
of their DNA. The genome of a prokaryote is structurally different from
a eukaryotic genome and in most cases has considerably less DNA. Prokaryotes generally have circular chromosomes, whereas eukaryotes have linear chromosomes. In addition, in prokaryotes the chromosome is associated with many fewer proteins than are the chromosomes
of eukaryotes. Also unlike eukaryotes, prokaryotes lack a nucleus; their chromosome is located in the nucleoid, a region of cytoplasm that is not enclosed by a membrane. In addition to its single chromosome, a typical prokaryotic cell may also have much smaller rings of independently replicating DNA molecules called plasmids most carrying only a few genes.
#BacterialCellStructure
#RoleOfDifferentStructuresPresentInBacteria
Thank you too much sir you are so much great and much great ❤️❤️❤️❤️ I am a biggest fan of you 💖💖💖💖💖💖 God always increase your knowledge ❤️❤️❤️❤️❤️❤️
Very helpful 👍 mashallah
Mashallah Sir G may Allah bless you
Mashalllahhhh ❤️❤️❤️ sir Alllah ap ko is ka ajar da.
you always increase my interest in biology thank you sir.👍👍
Amazing... thank you so much 👍🙏🏿🙏🏿🙏🏿🙏🏿
Lecture is very helpful..
Jazha Kallahu khoiron..
Thank you sooo much sir 🥰
Ma sha ALLAH 😊
thank you for enough and best explanation
😊
Very helpful.. gorgeous lectures
Thank you sir ❤
Thanku so much sir 🙏🙂
Thank you sir your teaching style is amazing
Nice and also helpful 👍 lecture thanks 👍👍👍👍 sirrrrrrr
Amazing lectures...but S means svedberg's unit not for size
Your knowledge is very Usefull....
Sir
Video is awesome sir
Thanks for the video
Sir please recommend me the name of this book or any other book for 12 bio.
Nice lecture
Thank you so much sir well explained jazakallah sir bless you
Thanks and welcome
Most welcome sir
❤❤❤❤mashallah good sir from bannu
Thank you so much sir g
sir your laecture is very helpful
Love from India
Sir g full course uploaded ni ha kia? All chapter ni mil rahy ha
Thank you sir
Plzz MCQs link snd in discription in every lecture
Thank you so much sir ☺️
Wow good lecture
Sir difference between peptidoglycan and glycoprotein
Peptide word tb use Kiya jata h jb protein bond ki bt ho ....protein ka carbs k sath bond ...
Or glycoproteins agr wese Kisi cell mn carbs or proteins present hon
Good lecture
Thank you so much 💕🥰❤️🥰❤️ sir g
very good sir
Sir capsule tu glycocalyx ki type hana na
Thanks u😮
Good 👍👍👍👍👍👍
lecture
❤❤❤
Mashallah
Sir please cynobacteria/bacteria aur 19 group ke bare me explain kar de
2nd part link
i need these slides
Take screenshot
Sir how the mesosome helps in dna replication plzz is ko explain kar dain?
Basically central mesosome Is believed to participate in DNA replication
❤❤❤❤
Thin aur patli me kya difference h
No difference bro
Sir first discovered bacteria name
Ehrenberg
Discovered Anton van leeuwenhoek
sir you are cute and genius teacher how
Sir onion practical ka bary me bato
Sir sexual reproduction n bol ke hm conjugation bol skte h
Thank u sir
Hey buddy itz not human gut itz animal gut (methanogens) 🇰🇷🇰🇷🇰🇷 rumanent animals
Sir i am new
jay hind
Bcz ...
Knowledge sabke liy hoti hain kisi 1 ke liy nhai .
Wishing sabko hoti h kisi 1 relegion ko nhai
Only difference of language rest is same( wish)
Language is just a medium not a religion . नमस्कारम
Bs course he
Ydi aap aasalam walekum ko hta ker ...
Morning kerte to ita a very good attraction ...
Dear, us students should be more concerned with the content provided by the lecturer rather than focussing on how they choose to greet their viewers. It’s solely their choice. I hope you understand that.