this is the overall information about the bacterial cell organization and ultra structure of bacteria and types of bacteria on the basis of cell wall. structure of bacterial plasmid and types of bacterial plasmid
2. Prokaryotic and eukaryotic cell structurehabtamu biazin
Prokaryotic and Eukaryotic cell
All living cells can be classified as
Prokaryotes cells: pre-nucleus
the Greek words pro (before) and karyon (nucleus).
All prokaryotes are:
single-celled organisms and all are bacteria.
Microscopic
cells lack a nucleus and other membrane-enclosed structures.
2. Prokaryotic and eukaryotic cell structurehabtamu biazin
Prokaryotic and Eukaryotic cell
All living cells can be classified as
Prokaryotes cells: pre-nucleus
the Greek words pro (before) and karyon (nucleus).
All prokaryotes are:
single-celled organisms and all are bacteria.
Microscopic
cells lack a nucleus and other membrane-enclosed structures.
Bacteria Structure, Cell wall, Cell Membrane, Cytoplasm, Ribosomes.pptxTagore medical College
Bacteria typically consist of a cell wall, cell membrane, cytoplasm, ribosomes, DNA, and sometimes flagella or pili for movement and attachment. They lack membrane-bound organelles like those found in eukaryotic cells. The cell wall provides structure and protection, while the cell membrane regulates what enters and exits the cell.
Living material is organized in unit and microorganism were living form of microscopical size and usually unicellular in structure originally classification is unsatisfied.
Ultrastructure and characterstic features of bacteria.Archana Shaw
Ultrastructure and characterstic features of bacteria: BACTERIA AS A MODEL ORGANISM
THIS WAS MY PRESENTATION TOPIC IN CLASS. THOUGHT OF SHARING IT AND HOPE IT HELPS.
This is the information about biostatistics and there are various test which are performed in the laboratory to the field. these tests are f test chi square test etc. on the basis of these data we confirmed probability and calculation of variability. here is the whole information about the chi square test
Biosenser are now a days a very helpful device which have various application in the field of medical in this presentation i described about biosensors and their types major application of biosensors
this presentation is based on bacterial recombination and how bacteria recombine with different techniques like conjugation transduction and transformation what are the various techniques which are used for transformation what are experimental methods which are used like electroportation. i also described about the dna repair system DNA repair system is well decscribed in the molecular biology of the gene written by JAMES D. WATSON you can get the complete knowledge with the help of this book.Here i shortly summarize the repair mechanism like nucleotide base excision repair mismatch repair sos repair. i also give some information about disease associated with defective DNA repair system
this is presentation on vitamin a production by the microorganism various microorganism produced vitamin a commercially by which we can obtain it easily and produced industrial application. what are the vitamin a classification and production
This presentation emphasize about drugs. Drugs which are made up of Recombinant DNA technology and how it produce and various types of drugs which are industrially important and commercially produced by the help of some microorganism like e.coli .How these drugs are classified within the ACT system what are the biosafety assessment of these durgs and pharmaceutical companies to provide guidelines for the drugs production various ethical issues related to the drugs like justice ,honest etc. I gave information about the top 10 pharmaceutical companies associated in the world and India also. What is drug abusement and what are the drugs pollution you can also found in this presentation
A brief information about the SCOP protein database used in bioinformatics.
The Structural Classification of Proteins (SCOP) database is a comprehensive and authoritative resource for the structural and evolutionary relationships of proteins. It provides a detailed and curated classification of protein structures, grouping them into families, superfamilies, and folds based on their structural and sequence similarities.
What is greenhouse gasses and how many gasses are there to affect the Earth.moosaasad1975
What are greenhouse gasses how they affect the earth and its environment what is the future of the environment and earth how the weather and the climate effects.
Introduction:
RNA interference (RNAi) or Post-Transcriptional Gene Silencing (PTGS) is an important biological process for modulating eukaryotic gene expression.
It is highly conserved process of posttranscriptional gene silencing by which double stranded RNA (dsRNA) causes sequence-specific degradation of mRNA sequences.
dsRNA-induced gene silencing (RNAi) is reported in a wide range of eukaryotes ranging from worms, insects, mammals and plants.
This process mediates resistance to both endogenous parasitic and exogenous pathogenic nucleic acids, and regulates the expression of protein-coding genes.
What are small ncRNAs?
micro RNA (miRNA)
short interfering RNA (siRNA)
Properties of small non-coding RNA:
Involved in silencing mRNA transcripts.
Called “small” because they are usually only about 21-24 nucleotides long.
Synthesized by first cutting up longer precursor sequences (like the 61nt one that Lee discovered).
Silence an mRNA by base pairing with some sequence on the mRNA.
Discovery of siRNA?
The first small RNA:
In 1993 Rosalind Lee (Victor Ambros lab) was studying a non- coding gene in C. elegans, lin-4, that was involved in silencing of another gene, lin-14, at the appropriate time in the
development of the worm C. elegans.
Two small transcripts of lin-4 (22nt and 61nt) were found to be complementary to a sequence in the 3' UTR of lin-14.
Because lin-4 encoded no protein, she deduced that it must be these transcripts that are causing the silencing by RNA-RNA interactions.
Types of RNAi ( non coding RNA)
MiRNA
Length (23-25 nt)
Trans acting
Binds with target MRNA in mismatch
Translation inhibition
Si RNA
Length 21 nt.
Cis acting
Bind with target Mrna in perfect complementary sequence
Piwi-RNA
Length ; 25 to 36 nt.
Expressed in Germ Cells
Regulates trnasposomes activity
MECHANISM OF RNAI:
First the double-stranded RNA teams up with a protein complex named Dicer, which cuts the long RNA into short pieces.
Then another protein complex called RISC (RNA-induced silencing complex) discards one of the two RNA strands.
The RISC-docked, single-stranded RNA then pairs with the homologous mRNA and destroys it.
THE RISC COMPLEX:
RISC is large(>500kD) RNA multi- protein Binding complex which triggers MRNA degradation in response to MRNA
Unwinding of double stranded Si RNA by ATP independent Helicase
Active component of RISC is Ago proteins( ENDONUCLEASE) which cleave target MRNA.
DICER: endonuclease (RNase Family III)
Argonaute: Central Component of the RNA-Induced Silencing Complex (RISC)
One strand of the dsRNA produced by Dicer is retained in the RISC complex in association with Argonaute
ARGONAUTE PROTEIN :
1.PAZ(PIWI/Argonaute/ Zwille)- Recognition of target MRNA
2.PIWI (p-element induced wimpy Testis)- breaks Phosphodiester bond of mRNA.)RNAse H activity.
MiRNA:
The Double-stranded RNAs are naturally produced in eukaryotic cells during development, and they have a key role in regulating gene expression .
This presentation explores a brief idea about the structural and functional attributes of nucleotides, the structure and function of genetic materials along with the impact of UV rays and pH upon them.
Slide 1: Title Slide
Extrachromosomal Inheritance
Slide 2: Introduction to Extrachromosomal Inheritance
Definition: Extrachromosomal inheritance refers to the transmission of genetic material that is not found within the nucleus.
Key Components: Involves genes located in mitochondria, chloroplasts, and plasmids.
Slide 3: Mitochondrial Inheritance
Mitochondria: Organelles responsible for energy production.
Mitochondrial DNA (mtDNA): Circular DNA molecule found in mitochondria.
Inheritance Pattern: Maternally inherited, meaning it is passed from mothers to all their offspring.
Diseases: Examples include Leber’s hereditary optic neuropathy (LHON) and mitochondrial myopathy.
Slide 4: Chloroplast Inheritance
Chloroplasts: Organelles responsible for photosynthesis in plants.
Chloroplast DNA (cpDNA): Circular DNA molecule found in chloroplasts.
Inheritance Pattern: Often maternally inherited in most plants, but can vary in some species.
Examples: Variegation in plants, where leaf color patterns are determined by chloroplast DNA.
Slide 5: Plasmid Inheritance
Plasmids: Small, circular DNA molecules found in bacteria and some eukaryotes.
Features: Can carry antibiotic resistance genes and can be transferred between cells through processes like conjugation.
Significance: Important in biotechnology for gene cloning and genetic engineering.
Slide 6: Mechanisms of Extrachromosomal Inheritance
Non-Mendelian Patterns: Do not follow Mendel’s laws of inheritance.
Cytoplasmic Segregation: During cell division, organelles like mitochondria and chloroplasts are randomly distributed to daughter cells.
Heteroplasmy: Presence of more than one type of organellar genome within a cell, leading to variation in expression.
Slide 7: Examples of Extrachromosomal Inheritance
Four O’clock Plant (Mirabilis jalapa): Shows variegated leaves due to different cpDNA in leaf cells.
Petite Mutants in Yeast: Result from mutations in mitochondrial DNA affecting respiration.
Slide 8: Importance of Extrachromosomal Inheritance
Evolution: Provides insight into the evolution of eukaryotic cells.
Medicine: Understanding mitochondrial inheritance helps in diagnosing and treating mitochondrial diseases.
Agriculture: Chloroplast inheritance can be used in plant breeding and genetic modification.
Slide 9: Recent Research and Advances
Gene Editing: Techniques like CRISPR-Cas9 are being used to edit mitochondrial and chloroplast DNA.
Therapies: Development of mitochondrial replacement therapy (MRT) for preventing mitochondrial diseases.
Slide 10: Conclusion
Summary: Extrachromosomal inheritance involves the transmission of genetic material outside the nucleus and plays a crucial role in genetics, medicine, and biotechnology.
Future Directions: Continued research and technological advancements hold promise for new treatments and applications.
Slide 11: Questions and Discussion
Invite Audience: Open the floor for any questions or further discussion on the topic.
Multi-source connectivity as the driver of solar wind variability in the heli...Sérgio Sacani
The ambient solar wind that flls the heliosphere originates from multiple
sources in the solar corona and is highly structured. It is often described
as high-speed, relatively homogeneous, plasma streams from coronal
holes and slow-speed, highly variable, streams whose source regions are
under debate. A key goal of ESA/NASA’s Solar Orbiter mission is to identify
solar wind sources and understand what drives the complexity seen in the
heliosphere. By combining magnetic feld modelling and spectroscopic
techniques with high-resolution observations and measurements, we show
that the solar wind variability detected in situ by Solar Orbiter in March
2022 is driven by spatio-temporal changes in the magnetic connectivity to
multiple sources in the solar atmosphere. The magnetic feld footpoints
connected to the spacecraft moved from the boundaries of a coronal hole
to one active region (12961) and then across to another region (12957). This
is refected in the in situ measurements, which show the transition from fast
to highly Alfvénic then to slow solar wind that is disrupted by the arrival of
a coronal mass ejection. Our results describe solar wind variability at 0.5 au
but are applicable to near-Earth observatories.
(May 29th, 2024) Advancements in Intravital Microscopy- Insights for Preclini...Scintica Instrumentation
Intravital microscopy (IVM) is a powerful tool utilized to study cellular behavior over time and space in vivo. Much of our understanding of cell biology has been accomplished using various in vitro and ex vivo methods; however, these studies do not necessarily reflect the natural dynamics of biological processes. Unlike traditional cell culture or fixed tissue imaging, IVM allows for the ultra-fast high-resolution imaging of cellular processes over time and space and were studied in its natural environment. Real-time visualization of biological processes in the context of an intact organism helps maintain physiological relevance and provide insights into the progression of disease, response to treatments or developmental processes.
In this webinar we give an overview of advanced applications of the IVM system in preclinical research. IVIM technology is a provider of all-in-one intravital microscopy systems and solutions optimized for in vivo imaging of live animal models at sub-micron resolution. The system’s unique features and user-friendly software enables researchers to probe fast dynamic biological processes such as immune cell tracking, cell-cell interaction as well as vascularization and tumor metastasis with exceptional detail. This webinar will also give an overview of IVM being utilized in drug development, offering a view into the intricate interaction between drugs/nanoparticles and tissues in vivo and allows for the evaluation of therapeutic intervention in a variety of tissues and organs. This interdisciplinary collaboration continues to drive the advancements of novel therapeutic strategies.
3. Bacterial cell
Morphology Arrangement
1. Size and Shape 1. Coccus
2.Structure 2. Bacillus
i. Capsule 3. Spirillus
ii. Flagella 4. Other forms
iii. Pilli & Fimbriae i. Pleomorphic
iv. Cell wall ii. Trichome
v. Cytoplasm iii. Palisade
a.Nucleoids iv. Hyphae
b. Plasmid
c. Cell component
vi. Endospore
4. Bacterial Size and Shape
The size, shape and arrangement of microbial cells vary with species to which
they belong.
Most bacterial cells range in size from 0.2 to 10 microns
Thiomargarita namibiensis is world’s largest bacteria , a gram- negative
Proteobacterium found in the ocean sediments off the coast of Namibia
Mycoplasma genitalium a parasitic bacterium which lives in the Primate
bladder waste disposal organs genital and respiratory tracts is a smallest
bacteria.
Antony Van Leeuwenhoek first observed bacteria through a microscope
and called them Animalcule.
He is also known as FATHER OF MICROBIOLOGY and bacteriology.
Ehrenberg 1829 coined the term Bacteria.
5. COCCUS
. Cocci (s., coccus) are roughly spherical cells. They can
exist singly or can be associated in characteristic
arrangements that can be useful in their identification.
Diplococci (s., diplococcus) arise when cocci divide and
remain together to form pairs. Long chains of cocci
result when cells adhere after repeated divisions in one
plane; this pattern is seen in the genera Streptococcus,
Enterococcus, and Lactococcus
6. B. megaterium-rods in chains
comma-shaped vibrios
BACILLUS
Bacillus megaterium is an example of a bacterium with a rod shape
Forms of bacillus
Monobacillus
Diplobacillus
Streptobacillus
Vibrios are comma-shaped
Spirochetes are flexible, spiral-shaped bacteria
that have a unique, internal flagellar
arrangement
Other bacteria are pleomorphic, being
variable in shape and lacking a single,
characteristic form
VIBRIO
9. Bacterial cell membrane
The Fluid Mosaic Model of Bacterial Membrane Structure.
The cell envelope is defined as the
plasma membrane and all the
surrounding layers external to it. The
cell envelopes of many bacteria consist
of the plasma membrane, cell wall, and
at least one additional layer (e.g.,
capsule or slime layer). Of all these
layers.
Plasma membrane is the most
important because it encompasses the
cytoplasm and defines the cell. If it is
removed, the cell's contents spill into
the environment and the cell no longer
exists.
10. CELL WALL
The cell wall is the layer that lies just outside
the plasma membrane.
It helps maintain cell shape and protect
the cell from osmotic lysis
It can protect the cell from toxic
substances
After Christian Gram developed the Gram stain in 1884, it
soon became evident that most bacteria could be divided
into two major groups based on their response to the
Gram-staining procedure.
Gram-positive bacteria stained purple, whereas Gram
negative bacteria were pink or red.
11. Peptidoglycan structure
Peptidoglycan is composed of many identical
subunits. Each subunit within the sacculus
contains two sugar derivatives
N-acetylglucosamine (NAG) and N-acetylmuramic acid
(NAM), and several different amino acids
The amino acids form a short peptide consisting of
four alternating D- and L-amino acids
the peptide is connected to the carboxyl group of NAM
The backbone of each strand is composed of
alternating NAG & NAM residues
Many bacteria cross-link the strands by connecting the
D-alanine to diaminopimelic acid of the other strand
Other bacteria use a peptide interbridge instead .
The peptidoglycan sacculus is strong but elastic. It is able to
stretch and contract in response to osmotic pressure this is
due to the rigidity of the backbone coupled with the flexibility
of the cross links
12. Gram Positive Cell Wall
Most bacteria that stain Gram positive belong to
the phyla Firmicutes and Actinobacteria, and
most of these bacteria have thick cell walls
composed of peptidoglycan and large amounts of
other polymers such as teichoic acids
Teichoic acids are polymers of glycerol or
ribitol joined by phosphate groups
13. Gram negative cell wall
LPS has many important
functions. (1) It contributes
to the negative charge on
the bacterial surface
because the core
polysaccharide usually
contains charged sugars and
phosphate
(2) It helps stabilize outer
membrane structure
because lipid A is a major
constituent of the exterior
leaflet of the outer
membrane.
(3) It helps create a
permeability barrier
14. Flagella
Bacterial flagella are slender, rigid structures about
20 nm across and up to 20 11m long.
Monotrichous bacteria (trichous means hair) have
one flagellum; if it is located at an end, it is said to
be a polar flagellum
Amphitrichous bacteria (amphi means on both
sides) have a single flagellum at each pole.
lophotrichous bacteria (lopho means tuft) have a
cluster of flagella at one or both ends
Flagella are spread evenly over the whole surface of
peritrichous (peri means around) bacteria
Bacterial flagellum is composed of three parts
(1) The longest and most obvious portion is the
filament, which extends from the cell surface to the tip.
(2) The basal body is embedded in the cell envelope (3) a short, curved segment, the hook, links the
filament to its basal body and acts as a flexible
coupling.
15. Bacterial Plasmid
During 1950 working on conjugation process it was found that maleness in
bacteria is determined by a transmissible genetic element. When male and female
bacteria conjugate, every female is converted into a male. This inherited property
of male is called F factor which is transmitted by cell to cell contact. Therefore F is
a separate genetic element. 1952 J. Lederberg coined the term plasmid as a
genetic name for this element. Hence plasmid may be defined as a Small circular
self replicating and double stranded DNA molecule present in bacterial cell in
addition to its chromosome. It replicates independently during cell division and
inherited by both of daughter cells. Therefore, its function is not governed by the
bacterial chromosome.
Types of plasmid
Sex factor or fertility F factor
R (resistance) plasmid
Col plasmid
Ti plasmid
Ri plasmid
16. Bacterial Endospore
Bacterial only produced by certain members of the
genera Bacillus and Clostridium (rods), and
Sporosarcina (cocci) within the phylum Firmicutes.
endospores are extraordinarily resistant to
environmental stresses such as heat, ultraviolet radiation,
gamma radiation, chemical disinfectants, and desiccation.
The spore consists of a core surrounded by several layers
that vary significantly in composition.
The core has normal cell structures such as ribosomes and
a nucleoid but has very low water content
The spore coat protects the spore from chemicals and
various lytic enzymes such as lysozyme.
The inner membrane is extremely impermeable to various chemicals,
including those that cause DNA damage. The core has very low water
content, high amounts of dipicolinic acid complexed with calcium ions
(CaDPA), and a slightly lower pH, all of which contribute to the spore's
resistance to harsh conditions.
17. Sporulation
Sporulation may be divided into seven
stages. The cell's DNA is replicated
(stage I), followed by an inward folding
of the cell membrane to enclose part of
the DNA and produce the forespore
septum (stage II). The mother cell
membrane continues to grow and
engulfs the immature endospore in a
second membrane (stage III). Next,
cortex is laid down in the space
between the two membranes, and both
calcium and dipicolinic acid are
accumulated (stage IV). Protein coats
are formed around the cortex (stage V),
and maturation of the endospore
occurs (stage VI). Finally, lytic enzymes
destroy the sporangium, releasing the
spore (stage VII). Sporulation requires
about 10 hours in Bacillus megaterium.
0 Bacterial Spore Formation