Chem

Microbiology: study of small living things study of bacteria: bacteriology study of viruses: virology study of parasites: parasitology study of fungi: mycology

NOT ALL BACTERIA ARE PATHOGENS (disease causing)

antibiotic: used to treat bacterial infections and diseases (penicillin, mold, 1929) bioremediation: using bacteria to clean up toxins

pathogenesis: ability of an organism to be pathogenic virulence factors: toxins, receptors, cellular composition

innate immune response v.s. adaptive immune response

MRSA: Methicillin Resistant Staphylococcus Aureas (treatment is Vancomycin)

Bonding sequence: atoms → molecules → cells → tissues

Atoms: protons + neutrons +electrons protons: found in the core, positive charge, equal to atomic number neutrons: also found in the core, neutral charge, contribute to mass of an atom electrons: found outside the core in orbitals, negative charge, equal to number of protons

Bonds: ionic: donating electrons to fill a shell (stability) covalent: sharing electrons, one pair = single bond, two pair = double bond polarity: slightly unequal sharing of electrons hydrogen: determine and maintain structure, affected by temperature and pH, involved in proteins and DNA

solvent: liquid substance solute: dissolving substance

dehydration synthesis: using water to build molecules hydrolysis: using water to break down molecules

heat capacity: ability to absorb or retain heat (reactions give off heat)

pH scale: 1 (acidic) - 2 - 3 - 4 - 5 - 6 - 7 (water) - 8 - 9 - 10 - 11 - 12 - 13 - 14 (alkaline) human body range: 7.2-7.4

Biological molecules (organic molecules)
Carbohydrates:
easily used and best source of energy contain carbon, oxygen, hydrogen types: monosaccharide (small chain of carbons), disaccharide (two monos), polysaccharide (many monos) linked by dehydration synthesis example: glucose
Lipids:
insoluble, contain more energy than carbs but harder to break down fats: contain 3 carbon molecule glycerol + one (or more) fatty acids made by dehydration synthesis, broken down by hydrolysis classified by how many tails are attached monoacylgylcerols (one fatty acid tail), diacylglycerol (two), triacylglycerol (three) - can be saturated (contains all hydrogens) or unsaturated (lost hydrogens, formed double bonds) glycolipids: lipids with carbohydrates attached phospholipids: lipids with phosphates attached, form barriers between water inside the cell and outside the cell steroids: example cholesterol, found in cell membranes of eukaryotic cells or fungal plasma membrane

Proteins each proteins has a specific 3-D shape that is directly related to function made of amino acid building blocks (contain one carboxyl group and one amino group) also made of long sequences of linked amino acids called peptides (dipeptide = two amino, poly = many) peptide bond formed through dehydration synthesis of carboxyl and amino groups - four levels of structure (held together by hydrogen and disulfide bonds)

- can be denatured (pH and temp break hydrogen bonds) which causes changes in shape and therefore function
- two main types: structural, enzymes structural proteins: preserve structural integrity, used for motility enzymatic proteins: metabolism, lowers activation energy of reactions, holds reactants together during reactions

- Nucleic acids involved with cellular information and function as energy molecules two types: DNA, RNA
DNA (nucleotide): nitrogenous base (adenine, guanine, thymine, cytosine) + deoxyribose sugar + a phosphate
RNA: ribose sugar + uracil instead of thymine major energy molecule in cells is ATP (adenosine triphosphate)

Classification of Organisms: prokaryotes (no membrane-bound organelles) v.s. eukaryotes (organelles) organisms classified by genus and species name (ex: Clostridium tetani)

Bacteria:
- are small (0.1-.000001m) are classified by shape and multi-cell arrangements can move from their initial site (motility) infects by thwarting the body’s defenses mutates and evolves rapidly

Staining: positive, negative, simple, differential the Gram Stain (positive, negative, variable, nonreactive), developed by Hans Christian Gram, takes advantage of cell wall differences (exploiting the thickness of the peptidoglycan cell wall component negative (capsule stain) exposes capsules (virulence factor made of sugar) by staining the background and leaving a halo flagella stain: identifies presence of flagella which is used for motility
Ziehl-Neelsen (acid-fast): detects tuberculosis and leprosy by using heat to break down mycolic acid (a component of cell walls) endospore: detects small, tough, dormant structures that form in bacteria by using heat to penetrate the spore

Microscopy bright field (light): slide illuminated from below by white light electron microscope: uses particle beam of electrons to illuminate the specimen and magnify it

Bacterial Cell Wall is a protective barrier against: osmotic pressure changes and environmental stresses primary structure is peptidoglycan, which is composed of repeating sugar molecules (N-acetyl glucosamine NAG, N-acetyl muramic acic NAM)


Gram positive teichoic acid, provides rigidity to cell wall by cations such as Magnesium and Sodium wall teichoic acid part way v.s. lipoteichoic acid goes through cell wall and links plasma membrane
M protein, virulence factor that protrudes from cell wall, is required for infection and highly susceptible to mutations mycolic acid, waxy lipid makes cell resistant to environment and chemicals



Gram negative thin peptidoglycan layer have outer membrane called lipopolysaccharide layer (LPS) which is composed of lipids, proteins and polysaccharides contains porin proteins which form a channel through the outer later outer membrane also contains translocation protein system outer layer functions as endotoxin (Lipid A, O polysaccharide)

Structures outside the cell wall:
Glycocalyx:
sticky substance produced in cytoplasm and secreted protects against environmental stress and can be used a nutrition loosely attached = slime layer v.s. adhered tight = capsule adherence (staying in) is a major part of infection
Fimbriae:
sticky projections shorter than flagella only in Gram-negative genes can be easily transferred
Pili:
used for motility (twitching/gliding and extension/retraction) involved in development of biofilm transfer genetic material (antibiotic resistance, toxin production, defense against host)
Axial filaments: roll like a corkscrew only on spirochetes allow organisms to get into the blood as well as other tissues
Flagella:
used for motility long structures that extend far beyond the cell wall consists of: filament, hook, basal body filament: made of molecules of flagellin protein, only seen in bacilli two different arrangements of basal body: gram-positive (one pair of ringed structures) v.s. gram-negative (two pairs of ringed structures) configurations: - monotrichous: one flagellum located at the end of the cell - amphitrichous: two flagella, one at each end of the cell - lophotrichous: two or more flagella location at the same end of the cell - peritrichous: flagella surround the entire cell movement of flagella allow: - opportunistic infections, escape from host defense (defeat of host defense), systematic infection (damage to the host)