Recent Microbiology Lecture 1

What is microbiology

The study of microorganisms, living things that can’t be seen with a naked eye.

Positive roles of Microbes?

-Photosynthetic microbes produces 50% of the earths Oxygen (02).

-Helps with decomposition

-Helps cows digest grass

(Lactobacillus (yogurt), Saccharomyces cerevisiae (helps dough rise), Propionibacterium sharmanii (makes Swiss cheese) E.coli (Produces insulin and indican) Helps in sewage treatment, bioremediation.

Who are the creators of microscopes?

-Robert Hooke (30x, observed cells)

-Leewenhoek (275x, observed Protozoans and bacteria)

6 Types of Microbes

• Parasitic Worms (Eukaryotes)

• Bacteria and Archaea (Prokaryotes)

• Fungi ( Eukaryotes)

• Algae (Eukaryotic)

• Protozoans (Eukaryotic)

• Virus (Acellular)

Eukaryotes

Has a nucleus and larger in size

Prokaryotes

Lacks Nucleus

5 Kingdoms

-Animalia (Eukaryotes, Multicellular)

-Plantae (Eukaryotes, Multicellular)

-Fungi (Eukaryotes, Multicellular)

-Protista (Eukaryotes, Unicellular/Multicellular)

-Monera (Prokaryotes, Unicellular)

What are the 3 domains

-Bacteria (Peptidoglycan cell wall, unicellular)

-Achaea (Doesn’t have a peptidoglycan cell wall, live in extreme environments )

-Eukarya (Has a nucleus)

Fungi

-Absorbs organic material

-Chitin cell walls

-Yeasts (unicellular) Mold (Multicellular)

Protozoa

-Animal like protists

-Moves via cilia, flagella and pseudopodia.

-Unicellular

-Lacks cell wall

Algae

-Plant like protists

-Have a cell wall

-Photosynthetic

-Unicellular/ Multicellular

Binomial Nomenclature

-Carollus Linnaeus

-Organism Names must include the genus (capitalized) and species (not capitalized)

-Can be underlined or italicized

Abiogenesis (Spontaneous Gen)

-Aristotle

-Believes living organisms arise from nonliving matter

Who disproved the spontaneous gen and how?

-Louis Pasture

-Swan-necked Flasks

What causes fermentation?

Yeast- Alcohol

Bacteria- Acids

Robert Koch

-Koch’s Postulate (Proved that bacteria caused disease)

Ignaz Semmelweis

-Introduced handwashing during childbirth with chlorine

Joseph Lister

-Antiseptic surgical technique

-Used phenol to disinfect surgical tools

Florence Nightingale

-Introduced antiseptic technique and hygiene in the hospital & nursing school

John Snow

-Cured the cholera epidemic

-Introduced infection control and epidemiology

Edward Jenner

-Cured Cowpox

-Crated the first vaccine

How does vaccine works

A weakened form of the disease is injected in the body, the body then creates antibodies to attack it. In the future the body already knows how to fight the disease.

Louis Pasteur

-Made Rabies vaccine

Paul Ehrlich

-Created Compound 606 (treats syphilis)

-Magic Bullet (Selective toxicity)

-Chemotherapy (uses chemicals to treat diseases)

Alexander Fleming

-Dicovered Penicillium (Antibiotic)

Matter

anything that takes up space and has mass

Atoms

the smallest chemical units of matter

Electrons

negatively charged subatomic particles circling a nucleus

Nucleus

contains neutrons and protons

Neutrons

uncharged particles

Protons

positively charged particles

Element

composed of a single type of atom

Atomic number

equals the number of protons in the nucleus

Atomic mass

sum of masses of protons, neutrons, and electrons

isotopes

Elements that differ in number of neutrons in their nuclei

Unstable isotopes

Release energy during radioactive decay

Chemical bonds

when atoms combine by sharing or transferring valence electrons

Molecule

two or more atoms held together by chemical bonds

Compound

a molecule composed of more than one element

Hydrogen bonds

weak forces that combine with polar covalent bonds

Covalent bond

sharing of a pair of electrons by two atoms

Electronegativity

attraction of atom for electrons; the more electronegative an atom, the greater the pull its nucleus exerts on electrons.

Gelatinous

sticky substance surrounding the outside of the cell

-polysaccharides and/or polypeptides

Slime layer

Loosely attached, irregular

Glycocalyx

-Attach cells to surfaces->biofilm formation
-Prevent desiccation

Capsule

-May prevent bacteria from being recognized by host
-may prevent phagocytosis by immune cells

Biofilms

a collection of organisms that attach to each other and to surfaces

Flagella

-used for motility

-Work by rotation

Stucture:
filament, hook
basal body (Gram positive)

Monotrichous

One at one end

Amphitrichous

One or more at each end

Lophotrichous

2 or more at one end

Peritrichous

Flagella throughout surface

Positive, Movement in response to a stimulus

toward stimulus

Negative, Movement in response to a stimulus

away from stimulus

Endoflagella

form “axial filaments”

Endoflagella

covered by outer sheath, and wrap around the bacteria.

Axial filaments

Rotation produces corkscrew-like movement

Fimbriae

short, numerous, hair-like appendages used in attachment
- Important in biofilms

Pili

-Made of pilin proteins
-Longer than fimbriae, shorter than flagella
-Typically only one or two per cell
- Also called conjugation pili,
- For transfer of DNA

Cell Wall

Main component is peptidoglycan
-Protect cells from osmotic pressure
-Provide structural rigidity
-Support cell shape

Gram Positive

-Has a bigger peptidoglycan

-Teichoic acid often present, may be anchored to lipid
(Lipoteichoic acid)

Gram negative

- smaller peptidoglycan

-Outer membrane present
 Contains phospholipids, lipopolysaccharide
(LPS) and porin proteins
 Lipid A in LPS causes fever, inflammation,
shoc

-Periplasmic space present

Acid-fast bacteria

-High in lipid (mycolic acid)

-Mycobacteria

Major functions of the plasma membrane

-Permeability barrier

-Protein Anchor

-Energy Conservation

-Maintaining concentration and electrical gradient

Passive transport (no energy needed)

Down concentration gradient
○ (Simple) diffusion (small lipid, O2,
CO2, water)
○ Facilitated diffusion (transport
proteins)
○ Osmosis (water only)

Active transport (energy needed)

Against concentration gradient Passive

-uses permease, and ATP
○ Uniport
○ Antiport
○ Symport
-Group translocation

Diffusion

Goes through the phospholipid bilayer

Facilitated Diffusion

-Through a nonspecfifc channel protein

-Through a permease specific for one chemical, which causes shape change in the channel protein

Osmosis

-Diffusion of water through a specific channel protein or through a phospholipid bilayer.

-Water moves across selectively permeable membrane from high to low concentration of water.

Isotonic solution

A solution that has the same solute concentration as another solution.

Hypertonic solution

A solution that has a higher solute concentration than another solution.

-Water moves out of the cell. (Cell shrinks)

Hypotonic Solution

A solution that has a lower solute concentration than another solution.

-Water moves into the cell. (cell swells)

Group translocation

involves modification of transported molecules– Only in bacteria