Class: BI221 Microbiology Instructor: Dr. Elaine Vanterpool

Van Leewenhook- first observed living microorganisms and called them “animalcules” from rain water

Robert Hooke- observing cork using a microscope (small cells or boxes) cell theory-all living things are composed

of cells After Leewenhook, the thoery of

spontaneous generation came about forms of life can arise from the non-living

Rudolf Virchow-(theory of biogenesis) challenged the spontaneous generation and claimed that only living things can rise to living things

Spallanzani- showed that heating a nutrient broth after sealing did not give rise to microorganisms and suggested that microorganisms are in the air

Francesco Redi demonstrated that maggots appear on meat only when the flies were able to

directly lay their eggs on the meat

The causative agent of disease must be present in all cases of disease and must be absent from healthy animals

The agent of disease can be isolated from the diseased animal and can be grown in pure culture

The disease can be produced by inoculating a portion of the pure culture into healthy animals

The agent of disease can be re-isolated from infected animal

Discovered that heating solutions enough to kill microorganisms prevented spoilage- termed pasteurization

Joseph Lister was a surgeon that performed the first aseptic surgery (using phenol solution)

Edward Jenner was a physician who discovered that his milk maids never got smallpox (due to cowpox infection)

Performed a “clinical trial” on an 8 year old boy used a cowpox infected needle and

scratched the boy’s arm The boy only got mildly ill and

recovered . The boy never contracted smallpox- the

newly discovered vaccination Immunity provided long term protection

The host’s immune system plays a crucial role in protection against microbial invasion and infection.

Once a particular antigen enters the host, the host has immune cells which will identify and destroy the foreign antigen and maintains immunity against it. Antigen is a substance that when introduced into the

body stimulates the production of an antibody. Antigens include toxins, bacteria, foreign blood cells, and the cells of transplanted organs

If re-infected with the same organism (or antigen), the individual will be protected.

Paul Ehrlich discovered that salvarsan (derivative of arsenic) was effective against syphilis

Alexander Flemming accidentally discovered that the fungus Penicllium secreted an antibacterial substance that killed bacteria- termed penicillin.

Elaine Vanterpool Ph. D

Cocci-sphericalBacillus-rod

Cocci-bacillus vibrio

Spiral

Spirillum is more rigid and helical shaped

Spirochete is more flexible and corkscrew shaped

The cell envelope may be defined as the cell membrane and cell wall plus an outer membrane if one is present

An appendage on the bacterial cell wall that is responsible for attachment

Pili is a type of fimbria that is used for “sex” between bacteria. Joins bacteria to

transfer genetic information

Is a thin appendage arising from the surface of the cell which is used for locomotion. It is composed of flagellin in prokaryotes

Some bacteria can have either of the four arrangements of flagella Monotrichous Amphitrichous Lophotrichous Peritirchous

Peritrichous

Monotrichous

Lophotrichous

Amphitrichous

Tumbles in the absence of oxygen or light

The glycocalyx is usually described as the slime layer

The glycocalyx is usually secreted for the bacteria and is composed of sugar (polysaccharides), and/or polypeptides

If the glycocalyx is tightly attached to the cell wall, it is referred to as the capsule.

The capsule is pathogenic and prevents destruction by the host (resist pahgocytosis)

Lipopolysaccharide or LPS is found on the outer leaflet of the outer membrane of Gram-negative bacteria. As the name implies, LPS consists of a lipid region, termed lipid A, covalently linked to the polysaccharide region

May vary among bacteria

N-acetylglucosamine (NAG)

N-acetylmuramic acid (NAM)

Crystal violet binds

Passive Simple diffusion Facilitated diffusion Osmosis

Osmotic pressure-pressure required to move water

Isotonic-equilibrium of solute concentration outside and inside

Hypotonic-concentration of solutes outside is lower

Hypertonic-concentration of solutes outside the cell is greater than inside

Simple diffusion

Facilitated diffusion

Osmosis

Active transport-requires energy

Nucleoid-primitive nucleus (lacks membranes) Ribosomes- protein synthesis (70s for bacteria; 80s

for eukaryotes); can be inhibited by antibiotics Inclusion bodies

Metachromatic granules- inorganic phosphate Polysaccharide granules- consists of glycogen and starch Lipid inclusions- storage of poly-β-hydroxybutyric acid Sulfur granules- sulfur granules Carboxysomes- inclusions of ribulose 1,5 diphosphate

(nitrifying bacteria) Gas vacuoles- gases (usually aquatic organisms) Magnetasomes- contains iron oxide

Histones are present in the nucleus (DNA binding proteins)

Synthesize phospholipids, fats and steroids

Synthesize proteins destined to be glycoproteins, phospholipids

Modifies the proteins from the ER to become either a lipoprotein, glycoprotein or become a glycolipid

The powerhouse of the cell

Lysozymes-contain digestive enzymes Chloroplast-in plants and contains

chlorophyll to carry out photosynthesis Centrosome-plays a role in cell

division Perioxisomes-similar to lyzosomes;

contains oxidizing enzymes

Metabolism- the sum of all chemical reactions within living organisms

Catabolism-the breakdown of complex organic compounds into simpler ones

Anabolism- the building of complex organic molecules from simpler ones

The enzyme substrate complex- formed by temporary binding of enzymes and reactants and lowers the activation energy of the reaction (making the reaction rate quicker)- Lock-Key Theory

Note: A catalyst can actually speed up a chemical reaction without being changed Specific region for the substrate

is called the active site

Temperature pH Substrate concentration

saturation

NAD+-nicotinamide adenine dinucleotide NADP+- nicotinamide adenine

dinucleotide phosphate FAD- flavin adenine dinucletide FMN- flavin mononucleotide CoA- plays a role in the synthesis and

breakdown of fats

Most are electron carriers of the electron transport system

Competitive- fills the active site and prevents the interaction of the substrate

Non-competitive- does not compete with the active site of the substrate

Allosteric-when the inhibitor binds to another site other than the substrate binding site

Feedback inhibition- regulation by the end product of the reaction (or pathway)

Phosphorylation is the addition of a

phosphate group to a chemical compound Substrate-level phosphorylation-

generation of ATP by the transfer of a high energy phosphate to ADP

Oxidative phoshorylation- The synthesis of ATP coupled with electron transport

Photophosphorylation- The production of ATP in a series of redox reactions (usually the electrons from the chlorophyll starts the reaction)

A decomposition reaction of the break down of carbohydrates into simple components. Glycolysis- oxidation of glucose into pyruvic acid

(net gain of 2 ATP and 2 NADH) Kreb cycle-oxidation of acetyl to CO2 to gain 2 ATP, 6 NADH, 2 FADH2

Electron transport system- NADH and FADH2 are oxidized;oxidation-reduction reactions results in the generation of ATP.

= 36-38 ATP Total

The pentose-phosphate pathway-used to metabolize five carbon sugars, yielding 1 ATP and 12 NADPH

The Entner-Doudoroff pathway- results in 1 ATP and 2 NADPH

Anaerobic respiration-fermentation (without the use of oxygen)

Aerobic respiration-requires oxygen (final acceptor)

ETC is termed by a sequence of electron carriers used in

oxidative phosphorylation, where the transfer of electrons from

one electron carrier to the next releases energy (used to

generate ATP by chemiosmosis)

The protons generated by the ETS gets pumped across the inner mitochondrial membrane until a high concentration gradient of protons accumulate.

The protons then get pumped out of the mitochondrial membrane through the special pumps containing ATP synthase, which makes ATP

Does not require oxygen

Does not use Krebs

Releases energy from sugar, and other organic molecules

Produces only small amounts of ATP

Lactic Acid- glucose is oxidized into two pyruvic acids, which is used to form two ATP molecules

Alcohol-instead of lactic acid, the end product is acetylaldehyde to form two molecules of ethanol

Light-independent (Calvin-Benson Cycle)

Light-dependent (photophosphorylation) Cyclic

photophosphorylation Non-cyclic

photophosphorylation

Photoautotroph-use light as the main source of energy and uses carbon dioxide as the main source of carbon

Photoheterotrophs- uses light as a source of energy, but cannot convert CO2 to sugar; they use other organic material

Chemoautotrophs- uses electrons from reduced inorganic compound as source of energy (also uses CO2)

Chemoheterotrophs- uses electrons from hydrogen atom as source