Microbiology midterm studyguide

Microbiology Lecture Notes: I. Cell 1/27/14
1. Robert Hooke
2. Basic unit of structure and function in all living things.
a. Unicellular à Microscopic
b. Multicellular à Microscopic & Macroscopic
c. 2 main cell groups:
1. Eukaryote = True Nucleus
2. Prokaryote= Bacteria (only)
a. Karyo = nucleus, pro= pre, Eu= true
3. Components of a cell:
a. Nucleus: brain of cell; has nuclear membrane/envelope
1. DNA à Chromosomes (Genes) à make protein à
Macromolecule.
2. Mitosis, Cell Division
b. Nucleoid Material (Bacterial DNA; note: no nuclear membrane.
1. Essential Genes (instructions).
2.Nucleoid Material ONLY used for bacteria
a. Single Chromosome
i. Human chromosomes à ROD
c. Protoplasm: Composed of Karyoplasm & Cytoplasm
1. Water w/ particles dissolved/ suspended.
a. Cytoplasm= water based w/ organelles.
1. Eukaryotic à Ribosomes, mitochondria, chloroplasts in cytoplasm.
2. Prokaryotic à Ribosomes in cytoplasm.
d. Cell Membrane: Flexible Structure; phospholipid bi-layer.
1. Proteins à Peripheral; integral
2. Semi-permeable (selective).
3. Bacteria make ATP/metabolism mostly at cell
Membrane.
e. Cell Wall à Plant/Plant-like cell **RIGID**
1. Obtain Nutrients Via:
i. Absorption
ii. Ingestion
iii. Photosynthesis
2. Why is a cell wall needed?
i. Prevents swelling & bursting
ii. this can happen w/ photosynthesis.
3. Bacteria
i. Most Bacterial cells have a cell wall.
a. Absorption (water-based)
b. Need c. wall to prevent bursting & swelling.
ii. Typical bacterial cell:
a. Nucleoid material
b. Cytoplasm à ribosome’s
c. Cell membrane
d. Cell wall (MOST)
iii. Chemical in cell wall (LAB); staining techniques.
• Viruses:
1. Consists of nucleic acids (DNA or RNA)
a. and Protein coat
b. Not considered a living thing à NOT A CELLà
A particle.
2. Needs a host cell (Human, other animal, bacterial & plant).
a. Can only do harm if they attach to your cells. ***
4. Cellular Characteristics:
a. Reproduce (mitosis)
i. Exceptions à RBC’s & Platelets
ii. Dead bacteria à defined by lost ability to reproduce.
b. They use “food” as a nutrient source à “an energy source”
c. Synthesizeà cellular components.
d. Excrete wastes.
e. Respond to changes in their environment.
f. Mutate à change in DNA (humans à always bad)
i. Diseased state, etc. (in humans)
ii. Mutations in bacteria can be good or bad.
5. Taxonomy
a. Study of classifying, identify and naming organisms.
b. Kingdom à Phylum à Class à OrderàFamilyàGenusàSpecies.
(Specific).
c. Genus, species. à Staphylococcus, epidermidis.
i. Caps, lowercase; typing à Italics. (pg. 15 in bk).
d. Taxonomy à Binomial system (Linnaeus).
Kingdoms
Pro/Eu karyote
Details
Monera
Prokaryotes
BACTERIA!!! ONLY
Protista
Eukaryotes
Protozoa; animal like, unicellular organisms
Fungi
Eukaryotes
Mold, mildew, mushrooms, yeast
Animal
Eukaryotes Plant
Eukaryotes

6. Whitakker
a. Obtain Nutrients via:
i. Absorption (nutrients à dissolved).
ii. Ingestion (taking in solid/ particulate matter)
iii. Photosynthesis Pigment à cell needs chlorophyll.

b. Examples/notes
i. Bacteria à Mycoplasmà lacks cell wall
ii. Cyanobacteria à has chlorophyll à photosynthesis
iii. Most bacteria absorb
c. How organisms from other kingdoms obtain nutrients:
i. Most protozoa à ingest
ii. Fungi à absorb for nutrients à has a cell wall (no bursting).
iii. Animal à ingest
iv. Plant à photosynthesis
7. Ribosomal RNA
a. How to identify; what we look like.
b. Species à collection of proteins à expressed rRNA
c. 3 Distinct Cell Lines
i. Archaeobacteria
a. Adapt easily à survive longerà simpler in structure
à more primitive.
ii. Eubacteria
a. Cell Membrane, cell wall, nucleus
iii. Eukaryotes
a. Eukaryotes
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Chapter: ~ 4 1/28/14 1. Endosymbiotic Theory:
a. Mitochondria & chloroplasts have their own DNA.
b. Primitive Eukaryotic cell à takes in a primitive bacterial cell wall
i. Phagocytosis of primitive bacteria (symbiant).
c. Eukaryotic:
i. Animal Cell à Symbiant became mitochondria
ii. Plant Cell à Symbiant chloroplasts.
d. Explains (theory) why these structures have their own DNA. 2. Major Groups of Microbes:
A. Protozoa:
1. Single-celled eukaryotes
2. Animal-like à\ nutrients via ingestion.
a. \ lack rigid, cell wall, chloroplasts etc.
3. Most are mobile/ motile
4. Examples:
a. Amoeba:
i. Doesn’t swim but à “creeps” along the surface.
ii. Amoeboid movement/ cytoplasmic streaming
à formation of psuedopods.
à serves to help ingest & for movement.
b. Paramecium:
i. Has Cilia
ii. Pellicle (for protozoa) à Cover
a. Think “pea coat”
iii. 2 purposes for cilia:
a. Movement
b. Ingestion
c. Sporazoan à “resting body”; hybernation
à Not metabolically active. (in terms of bacteria).
1. Cystà form = sporazoan = protection
2. Cyst: Protective coat
a. Survive from host A to host B.
b. * Will become active when environment is favorable.
c. Can be found in water & soil.
3. Disease:
a. Difficult to treat à different forms (complex).
b. Found in intestinal tract of animals.
c. Overall à doesn’t cause a lot of human infection.
B. Algae à “plant-like”
1. Chloroplasts = \ photosynthesis
2. Can be unicellular or multicellular
a. Usually aquatic (in water).
b. Serve as a food source for other animals.
c. Blue, Green, Red (resp. infection w/ red).
3. Emulsifiers (algae)
4. Used to make anti-inflammatory drugs.
5. Used to make Agar (solid medium; used in lab).
a. Polysaccharide.
b. Like making jello.
c. Using a loop/needle puncturing the slant and determining where you see
growthà good tool to see if organism has flagella.
d. Growth at bottom of tube = possibly anaerobic.
e. When out of incubator à solid ; can re-melt via hot water bath.
C. Fungi à Eukaryotes à Rigid Cell wall à lack chlorophyll.
1. Mold à \Nutrients via ingestion (cell wall).
a. Has filaments (thread-like) à cylindrical
b. Ex’s à mold (ex- cheese),mildew, yeast.
i. Mold à Hyphae (#1); microscopic
a. Mycelium (# 10); macroscopic (same just diff. in #’s).
b. Aerial Hyphaeà penicillum notatium (penicillin).
ii. Moldà Bathroom (showerhead) à comes back
iii. Chronic \ responsible for chronic fungal infections \ takes long
time to develop.
2. Yeast
a. Eukaryotic (has nucleus); oval footballs shape.
b. Reproduce via Budding. (sometimes budding doesn’t break off).
1. \ pseudohyphae
c. Yeast, normal Flora (or microbiota).
1. Mouth, vaginal canal.
2 . Low pH à protects harmful bacteria fr. entering vaginal tract.
i. Yeast infections à antibiotics; opportunistic infections.
a. too much à yeast infection.
3. Diabetic type 1 à yeast (gums); can tell fr. yeast in gums.
i. Why? à Glucose high \ yeast use glucose. (pseudohyphae).
d. Yeast used in baking, making beer (fermentation).
à HIV à yogurt for gut bacteria.
à Should NOT have (immunocompromised).
D. Bacteria
1. Prokaryotic à lack true nucleus
2. Morphology (shape):
a. Coccus (cocci) à spherical, “barley-shaped”
b. Bacillis (bacilli) à Rod-shaped.
c. Spirillium à Spiral shape.
3. Arrangements:
a. Staph à (clusters of cells) ; “grape-like” (random division planes).
i. e.g. à Staphylococcus
ii. Arrangement = Clusters ; Shape = round cells
b. Strep à chains
i. Streptococcus
ii. Arrangement = chains (strepto) ; Shape = circular (coccus).
iii. Steptococcus pyogenes à sometimes put in blood agar.
iv. Coccobacillus à When bacteria get older , can look rounder
4. 2 Main groups of bacteria:
a. Eubacteria (what we look at in lab).
b. Archaicbacteria
note** à bacteria are more beneficial to us than harmful **
E. Viruses
1. Borderline b/w living & non-living
a. Defined as particles not cells.
2. Composition:
a. Nucleic acids (RNA or DNAà can have 2x or 1x of either).
b. Protein coat à greater in quantity.
3. Obligate intracellular parasite à
a. \ Requires a host cell:
Animal Cells
Human Cells
Bacterial Cells à Bacteriophage “phase”
i. Host cell à Replication; lacks cellular material to replicate
on their own.
4. Electron microscope à needed to see viruses.
a. Morphology : “Geometric” in shape, “robots”.
5. Need living tissue/ viable tissue as nutrient. • 1:10 ratio of human to bacterial cells.
• Bacteria à Chemical Converters!
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1. Chemistry 1/29/14
A. Study/science of interactions
1. Atom = matter is made up of atoms.
2. Matter = anything that has mass & occupies space.
3. Components of elements.
a. Nucleus
i. Protons (+)
ii. Neutrons (neutral)
iii. Electrons à Energy Shells (-)
Orbits 1st shell (max 2e-)
2nd (max 8e-)
“Octet Rule”
4. Definitions:
Atomic # : Number of protons
Atomic Weight: # of protons & # of neutrons.
a. # of protons determines the element.
à Isotopes: different atomic weight but same atomic #.
à Valence # : # of e- in the outermost shell.
Polar = means charge.
Bonds:
a. Ionic Bond à Transfer of e-‘s from 1 atom to another.
i. e.g. à NaCl (salt)
a. Na+ = cation
b. Cl- = Anion
ii. 1e- is transferred to Cl from Na.
b. Covalent bond: Share pairs of electrons.
à C-C=c means share; \ covalent.
i. 2 subtypes:
a. non-polar covalent bond
à share pairs equally
i. ex: CH4 (symmetrical)
b. polar covalent bond:
à shares pairs unequally.
i. ex: H20; partial charge + and – on each side.
* NaCl dissolves in water.
c. Hydrogen Bonds: Attraction of a proton.
i. Negative Charge: Oxygen atom; nitrogen atom
ii. Good solvent for chemical reactions (b/c we are made of water).
iii. Strength in numbers.
5. Chemical Reactions
a. Synthesis reactions: anabolic reactions
à A + B (reactants) à AB (product)
b. Degradation reactions: Decompose; catabolic
à ABà A + B
c. hydrolysis: break down (digestion)
i. Exchange reactions: Break old bonds to make new.
AB + CD à AC + BD
ii. Reversible Rxns:
AB à ß A + B
Vocab:
6. Chemical Energy: Occurs when bonds are broken or formed in a chemical reaction.
a. Endergonic : Energy directed inward.
i. Energy is being absorbed from the surroundings.
ii. Bonds being formed are weaker than those that are broken.
b. Exogonic: Energy directed outward.
i. energy released into the surroundings.
ii. Bonds being formed are stronger than those being broken.
c. Organic: carbon containing, but hydrogen must be associated w/ it.
d. Inorganic: “non-carbon containing”.
i. Exceptions CO2 & CO.
e. Solvent = liquid component
f. Solute= particle(s) suspended. Both make up the solution.
II. Inorganic acids, bases & salts:
A. Acid à substance (chemical); when added to water dissociates.
Ex: HCL
[H+] [Anion] –
B. Baseà when added to water, dissociates:
Ex: NaOH
[OH]- [Cation] +
• [OH-] = If more of OH- group defined as a base.
• [H+] = If more H+ in group defined as an acid. o \ Strength in numbers.
C. Salt à Substance that dissociates into a [Cation] & [Anion].
i. NaCl [Na+] [Cl-]
à \ no OH- or H+ à it’s a salt.
D. Buffer à Strong acids à weaker one
àStrong Base à weaker one

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