This document summarizes the structure of bacterial cells. It describes the key components including the cell wall, plasma membrane, and intracellular and extracellular structures. The cell wall differs between gram-positive and gram-negative bacteria. Gram-positive walls are thicker and contain higher amounts of peptidoglycan while gram-negative walls are thinner and contain an outer lipopolysaccharide membrane. Intracellular structures discussed include plasmids, ribosomes, and the nucleoid region containing DNA. Extracellular structures include fimbriae, flagella, and capsules.
What is bacteria?(Structures Present in Bacteria And their Functions | Prokar...sehriqayyum
Explains what bacteria is and where it exists.
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).
LEARN ABOUT:
- Bacteria
- The number of viruses on earth is staggering
- Pathogenic yeasts
- Helminths
- Harnessing bacteria
- Microbes on the tree of life
- Living and working together
- Archaea
- Protozoa
LEARN ABOUT:
- Bacteria
- The number of viruses on earth is staggering
- Pathogenic yeasts
- Helminths
- Harnessing bacteria
- Microbes on the tree of life
- Living and working together
- Archaea
- Protozoa
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.
Bacteria are unicellular, procaryotic microorganisms which have diverse shape size and structures. Bacteria are found almost everywhere on Earth. Even the human body is full of bacteria, and in fact is estimated to contain more bacterial cells than human cells. Most bacteria in the body are harmless, and some are even helpful. A relatively small number of species cause disease.
What is bacteria?(Structures Present in Bacteria And their Functions | Prokar...sehriqayyum
Explains what bacteria is and where it exists.
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).
LEARN ABOUT:
- Bacteria
- The number of viruses on earth is staggering
- Pathogenic yeasts
- Helminths
- Harnessing bacteria
- Microbes on the tree of life
- Living and working together
- Archaea
- Protozoa
LEARN ABOUT:
- Bacteria
- The number of viruses on earth is staggering
- Pathogenic yeasts
- Helminths
- Harnessing bacteria
- Microbes on the tree of life
- Living and working together
- Archaea
- Protozoa
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.
Bacteria are unicellular, procaryotic microorganisms which have diverse shape size and structures. Bacteria are found almost everywhere on Earth. Even the human body is full of bacteria, and in fact is estimated to contain more bacterial cells than human cells. Most bacteria in the body are harmless, and some are even helpful. A relatively small number of species cause disease.
Bacterial Morphology and Atomy.pptx microbiologyosmanolow
Microbiology is the study of the biology of microscopic organisms - viruses, bacteria, algae, fungi, slime molds, and protozoa. The methods used to study and manipulate these minute and mostly unicellular organisms differ from those used in most other biological investigations
Bacterial Morphology and Atomy.pptx microbiologyosmanolow
Microbiology is the study of the biology of microscopic organisms - viruses, bacteria, algae, fungi, slime molds, and protozoa. The methods used to study and manipulate these minute and mostly unicellular organisms differ from those used in most other biological investigations
Explore our comprehensive data analysis project presentation on predicting product ad campaign performance. Learn how data-driven insights can optimize your marketing strategies and enhance campaign effectiveness. Perfect for professionals and students looking to understand the power of data analysis in advertising. for more details visit: https://bostoninstituteofanalytics.org/data-science-and-artificial-intelligence/
Data Centers - Striving Within A Narrow Range - Research Report - MCG - May 2...pchutichetpong
M Capital Group (“MCG”) expects to see demand and the changing evolution of supply, facilitated through institutional investment rotation out of offices and into work from home (“WFH”), while the ever-expanding need for data storage as global internet usage expands, with experts predicting 5.3 billion users by 2023. These market factors will be underpinned by technological changes, such as progressing cloud services and edge sites, allowing the industry to see strong expected annual growth of 13% over the next 4 years.
Whilst competitive headwinds remain, represented through the recent second bankruptcy filing of Sungard, which blames “COVID-19 and other macroeconomic trends including delayed customer spending decisions, insourcing and reductions in IT spending, energy inflation and reduction in demand for certain services”, the industry has seen key adjustments, where MCG believes that engineering cost management and technological innovation will be paramount to success.
MCG reports that the more favorable market conditions expected over the next few years, helped by the winding down of pandemic restrictions and a hybrid working environment will be driving market momentum forward. The continuous injection of capital by alternative investment firms, as well as the growing infrastructural investment from cloud service providers and social media companies, whose revenues are expected to grow over 3.6x larger by value in 2026, will likely help propel center provision and innovation. These factors paint a promising picture for the industry players that offset rising input costs and adapt to new technologies.
According to M Capital Group: “Specifically, the long-term cost-saving opportunities available from the rise of remote managing will likely aid value growth for the industry. Through margin optimization and further availability of capital for reinvestment, strong players will maintain their competitive foothold, while weaker players exit the market to balance supply and demand.”
3. Introduction
• All bacteria are unicellular organisms that
reproduce by binary fission.
• Most bacteria are capable of independent
metabolic existence and growth, but species
of Chlamydia and rickettsia are obligately
intracellular organism.
• Bacterial cells are extremely small and are
most conveniently measured in microns (10-6
m).
• Bacterial cells are usually between 0.4 and
1.5 micro meter in short diameter.
4. Cell Morphology
• Bacteria have characteristic shape. The common
microscopic morphologies are :
spherical or ovoid ( cocci )
rod –shaped ( bacilli )
comma shaped ( vibrio )
spiral ( spirillum and spirochete )
• Some cocci characterristically grouped in pairs or
chains; some form grapelike clusters of sperical cells;
some round cocci form cubic packets.
• Bacterial cell of other species grow separately .
• The microscopic appearance is therefore valuable in
classification and diagnosis.
5.
6. Structure of Bacterial cell
The protoplast , i.e. the
whole body of living
material (protoplasm)
is bounded paripherally
by a very thin, elastic
and semipermeable
cytoplasmic
membrane.
Outside and colsely
covering this lies the
rigid ,supporting cell
wall, which is porous
and relativity
permeable.
7. 1] cell wall
The cell wall encases the protoplast and lies
immediately external to the cytoplasmic
membrane.
It is 10-25 nm thick, strong and relatively rigid,
though with some elasticity and openly porous ,
being freely permeable to solute molecules
smaller then 10 kDa in mass and 1 nm in diameter
It shows granular structure and lacks microfibrils.
Gram Positive and Gram negative bacteria have
different type of bacterial cell wall
9. Gram positive cell wall :-
• The Gram positive type wall is relatively thick
(about 30-100 nm) and it generally has a simple,
uniform appearance under the electron
microscope.
• Some 40 – 80 % of wall is made of tough, complex
polymer , peptidoglycan .
• In this type of wall the sacculus consists of
multilayered peptidoglycan which, during growth,
develops by the “inside–to-outside” mechenism.
10. continue…..
• Covalently bound to peptidoglycan are compounds
such as tichoic acid : typically ,substituted
polymers glycerol phosphate or ribitol phosphate.
• In some bacteria (e.g. mycobacterium ) the wall
contains lipids, while in others (strains of
streptococcus) it contains carbohydrates.
• The composition of the wall can vary with growth
condition ; for example in Bacillus , the availability
of phosphate affects the amount of cell wall
teichoic acids.
11.
12. Gram negative cell wall :-
• The cell walls of Gram-negative bacteria are more
chemically complex, thinner and less compact.
• Peptidoglycan makes up only 5 – 20% of the cell
wall, and is not the outermost layer.
• The peptidoglycan of Gram-negative bacteria is
located between the plasma membrane and an
outer, LPS membrane.
• This LPS membrane is similar to the plasma
membrane, but is less permeable and is composed
of lipopolysaccharides (LPS).
14. 2) Plasma membrane :-
• Plasma membranes in bacteria are composed of
phospholipids contain a polar group attached to a
3 carbon glycerol back bone.
• They are also two fatty acid chains dangling from
the other carbons of glycerol.
• The phosphate end of the molecule is hydrophilic
and is attracted to water.
• The fatty acids are hydrophobic.
• Membrane also contain protein.
15. • Typically 20 – 30 % membrane , Most of them are
placed in the membrane so that the hydrophobic
amino acid associate with the lipids in the
membrane and the hydrophlilic amino acids are
outside the membrane intercting with either the
cytoplasm.
Function :
• The plasma membrane is selectively permeable in
that is helps control what moves into and out of cell.
16. 3) Extracellular structure
• i) fimbriae or Pili :-
fimbriae or pili are
elongated or hair like
proteinaceous structures
which project from the cell
surface.
they are specifically on
those gram negative cell.
Fibriae are typically 2 – 3
nm in diameter and from
0.1 micrometer to several
micrometer in length .
They may occur all over the
cell or may be localized
17. •Flagella : -
• The flagella are made up
of a class of linear protein
call flagellins .
• Flagella which arise at
verious points on the cell
surface.
• Flagellated bacteria are
described as
monotrichous,lophotricho
u or petritrichous. Its
depending on how the
flagella are arranged.
18. •Capsule ( Slime layer) :-
• The capsule of most bacteria consists of a
polysaccharide.
• The bacteria of a single species can be classified in
different capsule serovas or serotype based on the
fine chemical structure of this polysaccheride.
19. 4)Intracellular structure
• Plasmids :-
• The term plasmid was first introduced by the
American molecular biologist Joshua lederberg in
1952.
• A plasmids is a short usually circular and double
stranded segment of DNA .
• That is found in the cytoplasm separate from the
main bacterial chromosome.
• Their size veries from 1 kbp to over 100 kilobase
pare.
20. • Plasmids are capable of autonomous replication.
• Plasmids can transfer genes from one cell to other
cell.
21. • Ribosomes :-
• The cytoplasm contains a
large number of solute low
and high molecular weigh
substunce.
• RNA and approximately
20,000 Ribosomes/cell.
• Bacteria have 70S
Ribosomes comprising 30S
and 50s subunit.
• Function :-
• Ribosomes as the
organelles for protein
synthesis.
22. •Mesosome :-
• Mesosome are covonluted or
multilaminated membranous bodies
visible in the electron microscope.
• They develop by complex invagination
of cytoplasmic membrane into the
cytoplasm.
• Function:-
• Functioning in the compartment of
DNA at cell division and at
sporulation.
• Having a function analogous to the
eukeryotic cell----providing a cell
membranous support for respiratory
enzyme.
23. •Nucleoid
• The nucleoid is a region of
cytoplasm where the
chromosomal DNA is located.
• It is not a membrane bound
nucleus, but simply an area of the
cytoplasm where the strands of
DNA are found.
• Most bacteria have a single,
circular chromosome that is
responsible for replication,
although a few species do have
two or more.
• Smaller circular auxiliary DNA
strands, called plasmids, are also
found in the cytoplasm.
24. Reference :-
• Bacteria in biology , biotechnology and
medicine 4th Edition
By Paul singleton
• www.structure of bacterial cell.com