OCTC-Micro-Chapter 3

What are the Processes of Life?
1.Growth and development = increase in size
2. Reproduction and heredity (genome) = increase in number
3. Responsiveness and movement = ability to react to environmental stimuli
4. Metabolism = controlled chemical reactions
Greek for “true nucleus”
Nuclear membrane surrounds DNA forming a nucleus
Greek for “before nucleus”
Two types of Prokaryotes:
Bacteria & Archaea
Eukaryotes Nucleus is bounded by?
nuclear membrane.
Eukaryote’s genome or nucleic acid for heredity material is?
Are Eukaryotes larger than prokaryotes and more complex or smaller than eukaryocytes and less complex?
Eukaryotes are larger than prokaryotes and more complex.
Eukaryotes have a _______ membrane?
Cytoplasmic membrane = plasma membrane containing the cytoplasm
Some Eukaryotes also have a ______outside the plasma membrane.
cell wall
Some Eukaryotes also have a ______outside the plasma membrane.
cell wall
Structures within the cytoplasm of Eukaryotes may include:
Endoplasmic Reticulum
Gogi apparatus.
Eukaryotes are:
algae, protozoa, fungi, animals, and plants
How long have prokaryotes been on Earth?
3.5 billion years.
How long have prokaryotes been on Earth?
3.5 billion years.
Prokaryote’s genome or nucleic acid for the chromosomes is ?
DNA which is not enclosed within a nuclear membrane, but located in the cytoplasm.
Prokaryote’s DNA is One circular chromosome called the?
Bacterial chromosome
Bacterial Chromosome is spread centrally throughout the_____? What is that region called?
the cell’s cytoplasm
This region is called the nucleiod.
Prokaryote’s DNA is One circular chromosome called the?
Bacterial chromosome
Bacterial Chromosome is spread centrally throughout the_____? What is that region called?
the cell’s cytoplasm
This region is called the nucleiod.
Are prokaryotes smaller or larger than eukaryotes?
Prokaryotes lack internal membrane bound what? (3 things)
Golgi apparatus
Prokaryotes contain ______in the cytoplasm for protein synthesis.
In prokaryotes, where do most metabolic reactions occur?
Cell membrane
Genetic material of most bacteria consist of a circular strand of DNA called the?
Bacterial Chromosome
Bacterial Chromosomes contains essential what?
essential genetic material for survival
Plasmids are not part of the ___?
bacterial chromosome
What are plasmids?-QOT
Plasmids are separate, double stranded circles of DNA fragments.
Are plasmids essential for bacterial growth and metabolism?-QOT
Plasmids often contain protective genes. Name 4.
Drug resistance
Fertility factors
Genes for producing toxins
Certain enzymes.
Plasmids can become integrated into?-QOT
bacterial chromosome.
Any DNA molecule LOVES to?-QOT
incorporate into another DNA molecule
Because Plasmids can become integrated into bacterial chromosome they are?
They are important tools used in genetic engineering
Plasmids can be manipulated in labs. What are two things that they can do?
they can be transferred from one bacterial cell to another bacterial cell or yeast cell.
Three Parts of Prokaryotic Cell are?
Structures External to the Cell Wall
The Cell Envelope
Structures Internal to the Cell Wall
Structures External to the Prokaryotic Cell Wall are:
One of the Structures External to the prokaryotic Cell Wall are Appendages which include:
One of the Structures External to the prokaryotic Cell Wall is Glycocalyx which can either be a:
Capsule Or Slime layer
Capsule resists phagocytosis
Slime layer doesn’t resist phagocytosis
Glycocalyces are a general term for?
substances surrounding bacterial cell
Many bacteria secrete slimy, or gummy materials on their surfaces called a
“sugar cup” or Glycocalyx
Glycocalyces = “sugar cup” that consists of?
Or both.
This gelatinous, sticky substance surrounds the outside of the bacterial cell wall. What is it?
Glycocalyces = “sugar cup” that consist ofPolypeptides(proteins),Polysaccharides
Or both.
Two Types of Glycocalyces-QOT
If the glycocalyx is organized and tightly attached=?
Two Types of Glycocalyces-QOT
If the glycocalyx is unorganized and loosely attached =?
Slime Layer-QOT
3 Functions of Capsules and Slime Layers
1.They aid in attachment to surfaces.
2. They prevent phagocytosis by WBC which increases the bacteria’s pathogenicity. (capsule slide in lab)
3. They protect the bacteria from dehydration.
What advantage does a glycocalyx provide a cell?-QOT
A glycocalyx provides protection from dying and being devoured. It may also help atach cells to one another and to surfaces in the environment.-QOT
Capsules allow the bacteria to attach to solid surfaces and form?
Where do Biofilms form? (name 7 places)
Infected tissues
Plastic catheters
Metal pacemakers
Industrial pipelines.
What are Biofilms?
Biofilms are a complex community of microbes that form a protective adhesive matrix that attaches microbes to surfaces.
what is a slimy community of microbes growing on a surface?
Microbes in a biofilm can be different what? 2 things
genera and species
In lab, we will learn to recognize Capsules using?
Negative stains
Negative Stains allow us to? Why?
“see” capsules because the capsule does not take up the stain. Capsule appears white
One example of a Negative Stain in lab uses the stain-QOT
India ink-QOT
does the stain, India ink, penetrate the capsule?
What does the capsule show up as using the stain India ink?
the capsule shows up as a white “halo” around K. pneumoniae.
What are functions of a capsule?
Aid in attachment to surfaces
Capsules inhibit phagocytosis
and intracellular digestion by phagocytic cells
Prevent drying out
Enhance formation of biofilms, stick to surfaces
Prokaryotic Cell
Glycocalyx Capsule
External Structures to the Cell Wall :
Appendages include:
Flagella for swimming
Pili for exchanging genetic info
Fimbriae for attaching to surfaces
Bacterial Flagella Can move by means of rotating flagella how many degrees?
Flagella are easily seen with which type of microscope?
electron microscope.
Can Flagella be seen with a light microscope?
Flagella are so thin they must be stained with a _____ Stain to observe under a light microscope.
Functions of Flagella
1.Propel microorganism away from harm
2.Propel microorganism toward food
Flagella Movement is called?
Taxis(taxi cab)
Positive taxis means to?
move towards
Negative taxis means to?
move away
3 Examples of Taxis:
Movement toward light = positive phototaxis
Movement toward chemical = positive chemotaxis
Flagella move bacteria by runs and tumbles
. Flagella move bacteria by ___ and _____?
runs and tumbles
When the flagellum runs what is it doing?
flagellum rotates counterclockwise and cell swims forward.
Runs is called what 2 things?
Runs called positive chemotaxis, or positive phototaxis
Prokaryotic movement-Run
Prokaryotic Movement Tumble
When the flagella tumbles, what does it do?
flagellum rotates clockwise and cell stops and tumbles and changes direction.
Tumbles are abrupt, random, changes in direction that ____? QOT
increase under unfavorable stimuli. QOT
Tumbles cause what kinds of taxis?
Tumbles cause negative chemotaxis, or negative phototaxis
Flagella are arranged in four ways-QOT
Flagella are arranged in four ways

1. Monotrichous=

one flagellum at end -QOT
Flagella are arranged in four ways:
2. Lophotrichous=
clump of flagella called a tuft, at one end of the cell-QOT
Flagella are arranged in four ways:
3. Amphitrichous=
flagella at two ends of cell-QOT
Flagella are arranged in four ways:
4. Peritrichous=
flagella covering entire cell- QOT
Monotrichous= one flagellum at end
Lophotrichous = tuft of flagella at one end
Amphitrichous = flagella at both ends
Peritrichous = surrounded by flagella

Endoflagella  form an Axial Filament 

Endoflagella form an Axial Filament, These bacteria move though their environment with a ____ rotation?
The microbe that causes _______ is a spirochete with an endoflagella.
syphilis, Treponema pallidum

Treponemapallidumcauses syphilis = spirochete

Are Fimbriae and Pili invloved in locomotion?
Are Fimbriae and Pili invloved in interations with other cells? QOT
Characteristics of fimbriae?

sticky, proteinaceous, bristlelike fibers.

 they make the bacterium look like a porcupine.

There may be hundreds or thousands of fimbriae per bacterial cell.


There may be hundreds or thousands of _____ per bacterial cell.
Fimbriae enable microbes to
stick to each other and to other surfaces.
Fimbriae can serve as _____ factors and are also called ______.
adherence factors , adhesions
Fimbriae are found forming ______.
Remember: Biofilms are slimy masses of bacteria adhering to surface such as:
Human tissue
Industrial pipeline
Aggregates of bacteria in liquid.
Fimbriae vs. Flagella
Pilus, pili Also called:
Conjugation pilus
Sex pilus
Pili are long hollow tubules composed of _____?
Pilus, pili are found in
gram negative bacteria.
gram negative bacteria usually have_____ pili per microbe.
one or two
Pili join two_____ together and transfer___ from one bacterial cell to another bacteria. What is this transfer called?
bacterial cells, DNA.
This transfer is called conjugation.
What is Conjugation?
Conjugation is a form of genetic exchange between bacteria. (Remember bacteria replicate asexually)-QOT
Remember bacteria replicate _____?
Photo of Conjugation
Three Parts of Prokaryotic Cell
1.Structures external to cell wall
2.The cell envelope
3.Structures internal to the cell wall.
Cell Envelope consist of two parts:
1.cell wall of prokaryotic cell
2.cell membrane of prokaryotic cell
Do human cells have a cell wall?
The Cell Wall of Bacteria is just outside the bacteria’s ______.
cell membrane
Bacterial Cell wall provides? (3 things)-QOT
1.Shape and rigidity
2.Protects bacterial cell from toxic substances
3.Most importantly, the cell wall prevents the cell from bursting or exploding in hypotonic solutions. (Fluid in our body)
Bacterial Cell wall is made up of ?-QOT
Repeating layers of rigid carbohydrate and protein layers called peptidoglycan (PG).
Archaea have cell walls but they are not made up of______?
Peptidoglycan is macromolecule found ONLY in _______?-QOT
Try to visualize a layered chain length fence, now stack the chain length fences one on top of the other.
Peptidoglycan is made up of long chains of?
polysaccharides (sugars) called glycans
Peptidoglycan is macromolecule found ONLY in _______?-QOT
Glycans are cross linked with _______ made up of four amino acids.
short peptide
The glycans (polysaccharides sugars) are made up of chemicals called?
1.N-acetylglucosamine or glucosamine abbreviated NAG
2. N-acetylmuramic acid or muramic acid abbreviated NAM
Two basic types of bacterial cell walls are?-QOT
1.Gram positive (20-80 nm, thick layer of PG)
2.Gram negative (2-7nm, thin layer of PG)
Gram-Positive Cell Walls Have thick layers of _______ pressed tightly against the cell membrane. There is little space between the cell wall and cell membrane.

Bacterial Cell Walls


Cell walls of gram positive bacteria retain crystal violet dye in _______ procedure. QOT
Gram staining-Bacteria appear purple under magnification.
Gram-Negative Cell Walls are composed of a much thinner layer of _____?-QOT
In Gram-Negative Cell Walls Periplasmic space is located where?
on either side (surrounds) the peptidoglycan layer.
Why is the Gram negative cell’s Outer Membrane unlike any other membrane in nature?
The outer membrane has a lipid bi-layer.
The inner leaflet of the outer membrane is made up of phospholipids and proteins (similar to a human cell membrane).
The more important outside leaflet of the Outer Membrane is made up of what layer?-QOT
Lipopolysaccharides layer called the LPS.
The lipid portion of LPS is known as?-QOT
Lipid A = endotoxin
Functions of LPS layer-QOT
1.LPS forms a protective barrier which excludes toxic compounds to bacteria including antibiotics
2.LPS resist phagocytocis and resist complement proteins.
3.When gram negative bacteria die, the LPS releases Lipid A an endotoxin.
Lipid A causes: KNOW THESE
Vasodilation that can lead to shock
Blood coagulation
Fibrinolysis (breakdown of blood clots)
Diarrhea, vomiting, gas
Intestinal hemorrhage
Any infection with Gram negative bacteria is cause for concern.Why?-QOT
Because treatment with antibiotics may kill the bacteria
Release Lipid A
Giving the antibiotic may cause more harm than good due to consequences: Lipid A.(Many types of Gastroenteritis caused by Gram – bacteria)
When covered with the decolorizer, does the Cell Wall of gram negative bacteria retain the crystal violet dye after decolorization?-QOT
No it does not
Gram negative bacteria cells look red under microscope due to what?
counterstain with saffarin dye
Name 4 Characteristics of Gram negative cell walls
1.Outer membrane contains LPS an extra barrier.
2.More impervious to antimicrobial agents, antibiotics, and disinfectants
3.More difficult to kill than Gram +
4.Lipid A causes gas, diarrhea, weakness, vomiting, fever, inflammation, vasodilation, shock, blood clotting, fibrinolysis, GI bleeding
Penicillin and cephalosporin kill bacteria by targeting the synthesis of ?
Penicillin and cephalosporin kill bacteria by targeting the synthesis of ?
Why does penicillin and cephalosporin not harm animal cells(Human cells)? QOT
because animal cell’s lack cell wall and PG.
Why do Penicillin and cephalosporin (barring allergic reactions) have few side affects on humans?
because they target the PG layer of the cell wall of bacteria
Do Archaea Cell Walls have peptidoglycan?
Archael Cell Walls do not have peptidoglycan and are classified as a separate Domain.
Archael cell walls contain variety of specialized what?
polysaccharides and proteins.
Do Archaea Cell Walls have peptidoglycan?
Archael Cell Walls do not have peptidoglycan and are classified as a separate Domain.
Most Archaea live in ______ environments”.
Have Archaea been found to be pathogenic to humans?
Have Archaea been found to be pathogenic to humans?
Some Archael cells can live in extreme environment such as? Name 4 things
Hot springs
Polar regions
Dead Sea
Bottom of oceans.
Examples of Eukaryote’s Cell Walls: Name 3 things
Plants and fungi have cell walls
Plants have cellulose in their cell wall
Fungi have chitin in their cell walls
Prokaryote’s Cell Walls:
Bacteria and Archaea have cell walls
Bacteria have peptidoglycan in their cell walls
Archaea lack peptidoglycan in their cell walls
Some bacteria lack cell wall entirely nameone-QOT
Mycoplasma pneumoniae naturally lacks a cell wall.
Mycoplasma pneumonia causes atypical pneumonia or walking pneumonia
Bacteria that lack cell walls will have a range of shapes from ____ to _____.
filamentous to spherical.
In the past, these bacteria that lacked a cell wall were mistaken for viruses because they are
so small in size.
Prokaryotic cell membrane is composed of
lipids and proteins in a phospholipid bilayer.
There are no steroids in prokaryotic cell membranes. (Remember this!! QOT)
There are no steroids in prokaryotic cell membranes. (Remember this!! QOT)
Do Eukaryotic cells have steroids in cell membranes?-QOT
Proteins in Bacterial cell membrane function as: 5 things
Recognition proteins
Carrier proteins
Channel proteins
Proteins in Bacterial Cell Membrane are the sites for: 3 things
Energy reactions
Nutrient processing and synthesis
Regulating transport.
Is the Bacterial Cell membrane selectively permeable? By what modes of transport?
Yes passive transport or active transport.
The Cytoplasm of Prokaryotes contains what 7 things? QOT
Ribosomes (70s)
Inclusions (reserve deposits of lipids, CHO, or vesicles that store gases)
Bacteria have thousands of _____(sites of protein synthesis) in the cytoplasm.
Are Bacterial ribosomes smaller or larger in size than eukaryotes ribosomes?-QOT
Bacterial ribosomes have a sedimentation rate of what number?-QOT
Eukaryotic Ribosomes have a sedimentations rate of?-QOT
Certain Antibiotics can selectively target the bacteria’s _________ which will inhibit ________ in the bacteria.
ribosomes of 70s, protein synthesis
If the bacteria cannot carry out protein synthesis, what will happen?
it will die.
Why do hypertonic solutions kill bacteria that would otherwise spoil these foods?-QOT
Bacteria crenate (lose water)
What are some examples of foods that are preserved in hypertonic salt environment?
Pickles are preserved in a hypertonic salt environment: Salted hams, salted fish
What is an example of a food that is preserved in hypertonic sugar environment?
Jams and jellies are preserved in hypertonic sugar environment

Pickles are preserved in a hypertonic salt environment: Salted hams, salted fish

Dehydration preserves dried fruit, dried grains. Why don’t the bacteria metabolize?
Because bacteria need water to metabolize
Do Eukaryotic Cells all have Cell Membranes?
Plants =
cell membrane, cell wall (cellulose), DNA
Algae =
cell membrane, some cell wall, DNA
Fungi =
cell membrane, cell wall (chitin), DNA
Animals =
cell membrane, DNA
Protozoa =
cell membrane, DNA
External Structures of Eukaryotic Cells:

Animals and protozoa cells lack cell wall but some contain_____(capsules) which anchor cells together

Fungi, algae, and plants lack _____ but contain____
glycocalyces, cell walls
Flagella =
extensions of cell membrane; protozoa, sperm cells of mammals (also in bacteria)
Cilia located on some _____ cells
Do Bacteria have cilia?-QOT
Bacteria do not have cilia!
Nucleus contains?
DNA which is surrounded by nuclear membrane
Cytoplasm contains:
Endoplasmic Reticulum
Golgi Body
Lysosomes, Peroxisomes, Vacuoles, and Vesicles, Centrioles
Membranous ans Nonmembranous organelles

Comparision of Prokaryote’s and Eukaryote’s 

Categories: Microbiology