Microbiology sheet

(1&2)

LECTURER: intro to microbiology

CORRECTED BY : Tamara Shawabkah

& Mohammad Jomaa

DATE: 18/9 + 22/9

Region in the body that don’t have microorganisms:

1) Blood

2) CSF

3) Upper part of stomach

Why Study Microbes?

1. Microbes and Man in Sickness and Health

• Parasitism; Pathogens (disease causing) • Infectious disease is leading cause of death in developing countries (45%). • Commensalisms; Natural Microbiota (do no harm) • Example :E.coli which is have rule in 1)absorption of vitamin K

2)digestion of un digested food 3)barrier of infection (by control the pH)

• Mutualisms; Natural Microbiota (do us good)

2. Major Modern Applications (Biotechnology):

• Recombinant DNA technology; cloning • Industrial Applications (antibiotics; chemical production via fermentation) • Sewage treatment to decompose organic matter • Bioremediation of toxic waste

3. The Role of Microbes in Ecosystems

• Sources for drug discovery (antibiotics & antiviral drugs) • Cycling of Elements (ecosystem management; global climate change) • Agriculture (crop diseases; nutrient enhancement)

Biotechnology & Bioremediation

• Biotechnology- when humans manipulate (micro)organisms to make products in an industrial setting

– Genetic engineering- create new products and “genetically modified organisms” (GMOs)

– Recombinant DNA technology- technology used to engineer GMOs capable of synthesizing desirable proteins (i.e. medicines, hormones, and enzymes)

• Bioremediation - activity of microbes in the environment

helping to restore stability or clean up toxic pollutants

– Oil spills

– Chemical spills

– Water and sewage treatment

The microbial world is made up of microorganisms and viruses.

Microbiology is the branch of biological sciences concerned with the study of

these microbes. Microorganisms are unicellular organisms (capable of existence as single cells), too

small to be seen with the naked eye. Among all forms of life on the earth,

microorganisms predominate in numbers of species and in biomass, but their

occurrence is generally under appreciated because of their small size and the need for

a microscope to see individual cells.

Although a light microscope is generally required to visualize a single microbial cell,

microbial colonies and communities can readily be observed in nature. Viruses are

noncellular entities and cannot be considered microorganisms. Viruses and cellular

microorganisms are considered microbes.

The term organism is a descriptive term that implies cellular life. Hence, micro-

organisms are a type of cellular life that is microscopic in size.

Viruses are not considered microorganisms because they are not cells. Viruses

consist of nucleic acid (DNA or RNA) enclosed in a protein coat. They lack many

essential properties of cells, including membranes, ribosomes and metabolic enzymes.

Viruses are considered microbes, but not microorganisms, and hence are not "alive".

Which are the microorganisms?

• Life forms, or other self replicating entity, that requires microscopy technology to be clearly visualized.

• All prokaryotic and many eukaryotic life forms.

• Many are unicellular, sometimes cells are organized in filaments or clumps, and others are complex with only a portion of their life cycle being microscopic.

• Most can carry out life processes independently from other cells, others are highly parasitic.

• They often require specialized techniques for their study: microscopy, culturing, biochemical and molecular.

Slide 6

We have two domain 1) prokaryotic 2) eukaryotic

This is major domain fold the organism

Difference between prokaryotic and eukaryotic

**Eukaryotic >>true nucleus, nucleus membrane, cytoplasmic

organelles (Golgi apparatus mitochondria …)

**prokaryotic>> means that is primitive >>there is no nucleus ,

nuclear material distributed in one part of the cytoplasm

In fact the prokaryotic cell nucleus called “nucleoid”

Nucleoid: it is the region where the chromosomes locate

Note: ribosomes present in both (eukaryotic and prokaryotic) but

there is deferent between them

In prokaryotic ribosome called 70s

In eukaryotic ribosomes called 80s

S: تعني عامل الترسية (sedimentation coefficient) ويتم حساب كميتها تجهاز

الطرد المركسي

subunitsmall subunit and large subunit:Each ribosomes contain 2

Small subunit Large subunit

40s 50s Eukaryotic

30s 50s prokaryotic

**The Eukaryotic cell would be about 50x bigger than the

prokaryotic cell

Slide 7 minute: 8

In prokaryotic cell >>the cell have DNA in the cytoplasm and they

have extra chromosomes

Extra chromosomes: is an DNA but it is independent from the

normal cell DNA and it is replication too

These extra chromosomes called plasmide

The gene that’s located on plasmid it’s not necessary for the

growth of bacteria ..While the shape and metabolism is

determined by normal chromosomes which is basic for bacteria

cell

من مثال : شخص لون عيونه زرقاء واخر سوداء ..هنا ال يمكن ان تتغير لون العيون

االزرق لالسود او العكس وكذلك البكتيريا ال يمكن ان يتغير شكلها بعد فترة ..الن هذه

…الصفات

Carried on the gene on the chromosome (normal chromosome)

What is the characteristic determined by plasmide ??

Eukaryotic Cell Prokaryotic Cell

Nucleus Present Absent

Number of chromosomes More than one One--but not true chromosome: Plasmids

Cell Type Usually multicellular Usually unicellular (some cyanobacteria may be

multicellular)

True Membrane bound Nucleus Present Absent

Example Animals and Plants Bacteria and Archaea

Genetic Recombination Meiosis and fusion of

gametes

Partial, undirectional transfers DNA

Microtubules Present Absent or rare

Endoplasmic reticulum Present Absent

Mitochondria Present Absent

Cytoskeleton Present May be absent

DNA wrapping on proteins.

Eukaryotes wrap

their DNA around

proteins called

histones.

Multiple proteins act together to fold and

condense prokaryotic DNA.

The trait that are not essential for the growth of bacteria for

example >>antibiotics resistant; enzyme production; toxins

transfer

Why?? Bactria are sensitive to x antibiotics. After period of time

the bacteria resistant to x antibiotic ….why?? Because gene that

code of resistance of antibiotics could o plasmide (jumping gene)

Bacteria can gain gene on plasmide and can eliminate it and can

transport it to another bacteria …and it is important in clinical

medicine to treat patients

وبالتالي ممكن ان plasmideومة والحساسية محمولة على هذا يعني ان صفة المقا

تنتقل من بكتيريا الخرى

Genes transfer from one bacteria to one another by 1)conjugation

(most popular) 2)transduction

Archea is an old bacteria that’s live in extreme environment such

as (high and low pH, high osmotic pressure, high and low

temperature)

Eukaryotic cell >> all organisms in the world expect 1)bacteria

2)Archea 3)green blue Algi

Eukaryotic Cell Prokaryotic Cell

Nucleus Present Absent

Number of chromosomes More than one One--but not true chromosome: Plasmids

Cell Type Usually multicellular Usually unicellular (some cyanobacteria may be

multicellular)

True Membrane bound Nucleus Present Absent

Example Animals and Plants Bacteria and Archaea

Genetic Recombination Meiosis and fusion of

gametes

Partial, undirectional transfers DNA

Microtubules Present Absent or rare

Endoplasmic reticulum Present Absent

Mitochondria Present Absent

Cytoskeleton Present May be absent

DNA wrapping on proteins.

Eukaryotes wrap

their DNA around

proteins called

histones.

Multiple proteins act together to fold and

condense prokaryotic DNA.

There is no bacteria with

constant characteristic for

its life (always change)

Minute: 19

histone is a basic protein

In prokaryotic cell there is some bacteria do photosynthesis so

that it has chlorophyll separated in cytoplasm not in chloroplast

Flagella is use to move

Ribosomes Larger smaller

Vesicles Present Present

Golgi apparatus Present Absent

Chloroplasts Present (in plants) Absent; chlorophyll scattered in the

cytoplasm

Flagella

Microscopic in

size; membrane

bound; usually

arranged as nine

doublets

surrounding two

singlets

Submicroscopic in size, composed of

only one fiber

Permeability of Nuclear

Membrane

Selective not present

Plasma membrane with

steroid

Yes Usually no

Cell wall

Only in plant

cells and fungi

(chemically

simpler)

Usually chemically complexed

Vacuoles Present Present

Cell size 10-100um 1-10u

Ribosomes Larger smaller

Vesicles Present Present

Golgi apparatus Present Absent

Chloroplasts Present (in plants) Absent; chlorophyll scattered in the

cytoplasm

Flagella

Microscopic in

size; membrane

bound; usually

arranged as nine

doublets

surrounding two

singlets

Submicroscopic in size, composed of

only one fiber

Permeability of Nuclear

Membrane

Selective not present

Plasma membrane with

steroid

Yes Usually no

Cell wall

Only in plant

cells and fungi

(chemically

simpler)

Usually chemically complexed

Vacuoles Present Present

Cell size 10-100um 1-10u

Eukaryotic Cell Prokaryotic Cell

Nucleus Present Absent

Number of chromosomes More than one One--but not true chromosome: Plasmids

Cell Type Usually multicellular Usually unicellular (some cyanobacteria may be

multicellular)

True Membrane bound Nucleus Present Absent

Example Animals and Plants Bacteria and Archaea

Genetic Recombination Meiosis and fusion of

gametes

Partial, undirectional transfers DNA

Microtubules Present Absent or rare

Endoplasmic reticulum Present Absent

Mitochondria Present Absent

Cytoskeleton Present May be absent

DNA wrapping on proteins.

Eukaryotes wrap

their DNA around

proteins called

histones.

Multiple proteins act together to fold and

condense prokaryotic DNA.

No histones

Note : flagella don’t have any association or related to the cell

speed in motion

Note :there is no relation ship between number of flagella and

active motion

Flagella determine only if there is motile or no

**bacteria can change its shape in respond to several factors such

as : 1)enviroment 2)radiation

in procaryoti cell there is some bactreia have steriod

for example>>myoplasma hominis one of the smallest bacteria

don’t have cell wall …..but it have plasma membrane with steroid

(3 lyers of steroid) ….(normal bacteria cell have cell wall and plsma

membrane without steroid)

steroid it is a fatty lyer have rule and affect many things like

motile and stabilty to the cell and many other things.

In prokaryotic cell >> the cell wall is very important part of the

bacteria because it is use in determing the type of gram stan (+ or -)

This part is very important in clinical medicine in diagnosis

Ribosomes Larger smaller

Vesicles Present Present

Golgi apparatus Present Absent

Chloroplasts Present (in plants) Absent; chlorophyll scattered in the

cytoplasm

Flagella

Microscopic in

size; membrane

bound; usually

arranged as nine

doublets

surrounding two

singlets

Submicroscopic in size, composed of

only one fiber

Permeability of Nuclear

Membrane

Selective not present

Plasma membrane with

steroid

Yes Usually no

Cell wall

Only in plant

cells and fungi

(chemically

simpler)

Usually chemically complexed

Vacuoles Present Present

Cell size 10-100um 1-10u

Ribosomes Larger smaller

Vesicles Present Present

Golgi apparatus Present Absent

Chloroplasts Present (in plants) Absent; chlorophyll scattered in the

cytoplasm

Flagella

Microscopic in

size; membrane

bound; usually

arranged as nine

doublets

surrounding two

singlets

Submicroscopic in size, composed of

only one fiber

Permeability of Nuclear

Membrane

Selective not present

Plasma membrane with

steroid

Yes Usually no

Cell wall

Only in plant

cells and fungi

(chemically

simpler)

Usually chemically complexed

Vacuoles Present Present

Cell size 10-100um 1-10u

By using gram stain >>(gram - =red // gram + =purple)

If we use lysosome or pencillin or others enzyme we can change

the structure of cell wall and change it.

Cell wall in prokaryotic cell called “peptidoglycan” or “mural”

Minute :28

Cell size… In prokyrotic cell >> myoplasma hominis it is very small

and don’t have cell wall …but it has nuclear material in cytoplasm

and have plasmic membrain which have steroide that supply and

give stability to the cell

Slide 9

Biologists recognize the existence of two fundamentally different types of cells in the microbial world,

called procaryotic and eucaryotic cells.

1. Eucaryotic cells have a "true" nucleus (the region of the cell that contains genetic information or DNA) that enclosed in a nuclear

membrane

2. Prokaryotic cells are said to have a "primitive" nucleus because their DNA is not enclosed within a nuclear membrane. The nuclear

region of a prokaryotic cell is sometimes referred to as a nucleoid, but

never as a nucleus.

Procaryotic and Eucaryotic cells

Eucaryotic cells are always bounded by a membrane, just as prokaryotic cells are.

Some eucaryotic cells are also surrounded by a cell wall, but eucaryotic cells do not have capsules.

Mitochondria are present in nearly all eucaryotic cells and produce the cell's energy by breaking down food.

Chloroplasts, in contrast, are present only in plants and algae and are used in photosynthesis, the process through which

the organism uses energy from the sun to build sugars.

Taxonomy of Life:

The classification, or grouping, of organisms based on common characters used to reflect their evolutionary relatedness. Types of groups, taxa, are arranged in a hierarchy from the most general (Domain) to most specific.

3 Domains based on molecular analysis of ribosomal RNA. (Carl Woese 1980s)

Two prokaryote domains: Bacteria and Archaea

A single Eukaryote domain.

Many Phyla within each domain.

Divided to 3 domains and each domains have several groups

Domain : Eukaryotic

Bacteria prokaryotic

Archae prokaryotic

Usually bacteria in lab live in normal temperature 37 (middle

temperature)

Every line represents a period of time and note the eukaryotic

and archea are closed to each other but prokaryotic its far away

Humans

• Domain: Eukarya • Kingdom: Animalia • Phylum: Chordata • Class: Mammalia • Order: Primata • Family: Hominidae • Group: Homo • Species: sapiens

Intestinal Bacterium

• Domain: Bacteria • (no kingdom) • Phylum: Proteobacteria • Class: γ-proteobacteria • Order: Enterobacteriales • Family: Enterobacteriaceae • Genus: Escherichia • Species: coli

Difference in taxonomy between us and them

The underline suffix “ales” mean order and the suffix “aceae”

mean family

Minute :34

Binomial nomenclature: (1+2)

1)Genus 2)species (must be italic or underlined)

Genus name must begin in capital letter

Example : E.coli O157:H7 >>(it is subspecies)

O mean >> one of somatic antigen and the number 157 it is one type of several type begin to numbering from 1

H mean >>flagella antigen and the number is type of several type

**bacteria may be capsulated or not capsulated (capsulated one is more dangerous to us than non-capsulated one)

One of the capsule functions is being anti-phagocytic and allows the bacteria to proliferation and distribute in your body

Minute :42

Bacteria is more common than Fungi

Deffernt in ways of motile

Amoeba>> Pseudopodia

Ciliate >>cilia

Flagellate >>flagella

Viruses: An infectious particle with an acellular organization of protein and nucleic acids (RNA or DNA), and lacking independent metabolism.

It requires the metabolism of a host cell in order to replicate. Viruses are about 50 to 200 nm in size.

Viruses can’t survive without living with another cell

Viruses that’s surrounded by envelpe called “enveloped viruse”

Compound microscope = bright filed microscope =student microscope

Elctron microscope 600,000x

Compound microscope 1000x

contain only one DNA or RNA and not both with protien Viruse

conain only protien Prion

contane only RNA and protien Virone

Prion: An infectious aberrant brain protein that causes abnormal aggregation of similar normal brain proteins; no nucleic acids. Causes dementia and madness.