Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
67 Cards in this Set
- Front
- Back
|
Robert Hooke
|
British Scientist
First to describe cells (1665) |
|
|
Anton van Leewenhoek
|
Not a scientist
Dutch merchant/politican Read Hooke's book and made his own microscope Saw all 3 basic shapes of bacteria 1st to see: Protozoa, Sperm, Red Blood cells, and capillaries |
|
|
Spontaneous Generation
|
living creatures arise from non-living things
|
|
|
Miasma
|
Gases or fumes rising from a diseased or dead individuals body
|
|
|
Theories of Disease
|
Miasma, Curses by witches, Inheritance, Punishment for sins, Germs (later)
|
|
|
Settled Spontaneous Generation
|
Redi and Pasteur
|
|
|
Redi
|
Meat/Maggot Experiment
Developed 1st controlled experiment "covered jar" experiment refuted spontaneous generation of Macroorganisms |
|
|
Settled Cause of disease
|
Jenner, Semmelweiss, Lister, Pasteur, and Koch
|
|
|
Jenner
|
Smallpox Experiment
British Scientist created first vaccine (1796) used cowpox to create immunity to smallpox |
|
|
Semmelweiss
|
Hungarian doctor
Observed high "childbirth fever" with doctors visiting cadavers before seeing patients without disinfecting hands or instruments Introduced use of lime water for disinfection Mortality rates decreased |
|
|
Lister
|
Aseptic Surgery
"Father of Aseptic Surgery" (1850's) Anesthesia increased mortality rates Expanded methods of Semmelwiess (less confrontational) introduced: heat sterilization of instruments, disinfection of wounds and dressings, and disinfection of air during surgery |
|
|
Louis Pastuer
|
French chemist
Pasteur's Wine Experiment -Proved microbes can metabolize Good wine = Ovals (yeast) Bad wine = Sticks (bacteria) along w/ ovals Developed Pasteurization (1857) S-Flask Experiment -Proved microbes do not spontaneously generate |
|
|
Koch
|
Prussian(German) doctor
Anthrax Experiment Studied cause of anthrax in cattle (1875) |
|
|
Koch's Postulates
|
Step 1: Pathogen present in all cases of disease (absent from healthy)
Step 2: Grow pathogen in pure culture Step 3: Cultured pathogen causes disease in healthy animal Step 4: Reisolate pathogen same as the original pathogen |
|
|
Pastuer-Attenuation
|
Weakening of pathogen to create a vaccine (accicdental)
-Methods: Aging culture - Drying culture or tissue containing organism (rabies virus), Exposure to weak acids, exposure to other harsh chemicals (formalin), and passage through animals |
|
|
Alexander Fleming
|
PHD and MD
Dirty dishes "accident" Isolated first antibotic - penicillen - from Penicillium notatum mold (1929) Penicillin not produced commerically until 1941 in US |
|
|
Prokaryotic Cells
|
Simple
No membrane bound organelles Unique features are targets for drugs |
|
|
Three Basic Shapes
|
Cocci - Round
Bacilli - Rods Spirilli - Spirals or curved cells |
|
|
Arrangements
|
Strepto - chains
Staphylo - grapelike clusters Diplo - twos Tetrads, Sarcina - square packets of 4 and 8 |
|
|
All Bacterial cells have
|
Cytoplasm - inclusions of lipid, starch, etc.
Ribosomes- 70S |
|
|
Drugs that attack ribosomes
|
Inhibition of protein synthesis
-karamycin -tetracycline -enthyromycin |
|
|
Cell membrane
|
Phosopholipid bilayer
|
|
|
Genome
|
DNA double helix molecule
Only one circular "chromosome" No nuclear membrane -Nucleoid region |
|
|
Drugs that attack genome
|
Inhibition of DNA or RNA synthesis
- Ciprofloxacin - Metronidazole |
|
|
Cell wall
|
Peptidoglycan
|
|
|
Peptidoglycan
|
2 alternating sugars: NAM and NAG
Cross-linkages: tetrapeptides Protects from cell bursting in water |
|
|
Wall exists in two alternatives
|
Gram + and Gram -
|
|
|
Gram +
|
Thick peptidoglycan
Many layers of Technoic Acids |
|
|
Gram -
|
Thin peptidoglycan
Fewer Technoic layers Outer LPS - lipopolysaccharide Lipid A (endotoxins) |
|
|
Drugs that attack peptidoglycan
|
Stronger effect on gram + (poor penetration of LPS)
-All -cillin drugs -Cefaclor -Bacitracin -Inhibition of cell wall synthesis |
|
|
Optional parts
|
Plasmids
Sex Pili Fimbrae Flagella Glycocalyx Endospores |
|
|
Plasmids
|
Small extra segments of DNA
Self-replicating Easily passed (CD compared to hard drive) |
|
|
3 kinds of plasmids
|
R plasmids
F plasmids T plasmids |
|
|
R plasmids
|
Resistance to antibiotics
Common Mechanisms: 1. Efflux pump pumps out drug 2. Enzymes break down drug 3. Enzymes alter drug |
|
|
F plasmids
|
Fertility genes
-Initiate conjugation -Make sex pili |
|
|
T Plasmids
|
Production of toxins
|
|
|
Sex Pili
|
Temporary (directions on F plasmids)
Tubular pilin protein Connect cells: allow DNA transfer |
|
|
Fimbrae
|
Short and numerous
Proteinaceous For adhesion to surfaces |
|
|
Flagella
|
Function - movement
Hair-like structures Stiff, curved Rotate - Counterclockwise - runs (moves one direction) - Clockwise - tumbles (goes crazy) |
|
|
Taxis
|
Movement in response to stimulus
- + stimulus: more runs, fewer tumbles - - stimulus: more tumbles, less runs |
|
|
Four Flagellar Arrangements
|
Lophotrichous - Tuft
Monotrichous - One Peritrichous - Surrounding Amphitrichous - Both ends |
|
|
Glycocalyx
|
Mucoid layer - polysaccharide or glycoprotein
Loose layer = slime layer Dense, thick layer = capsules |
|
|
Capsules
|
Confer increased pathogenicity
-Neutralize drugs -Fool/delay immune response (capsule first) -Adhere to surfaces -Avoid phagocytosis (WBC eating of cells) Help cell survive: - Nutrient source during starvation -Storage of toxic waste products |
|
|
Endospores
|
Dormat, Non-reproductive structures
Formedinside cell in bad conditions |
|
|
Sporulation
|
Layers of peptidoglycan + protein = spore coat
Water removed Dipicolinic acid added - heat stability -Spores contain Dipicolinic acid molecules to provide heat stability -Spores contain only small amounts of water |
|
|
Characteristics of Endospores
|
Highly resistant to harsh environmental conditions:
- Heat (survive boiling) - Harsh chemicals (alcohols, etc.) - Drying - Lack of nutrients - Germinate in favorable conditions to normal vegetative cells |
|
|
Endospore structure and types
|
Location: Central, Subterminal, Terminal
Size: Small, Medium, and Large Shape: Circle and Oval |
|
|
Drug Attack points
|
Inhibition of synthesis of :
-Cell wall -DNA or RNA - Protein - General metabolic pathway - Trimethoprim ( Interfer w/ production of folic acid) |
|
|
Unusual Bacteria
|
Mycoplasma - no cell wall (some pneumonias)
Rickettsia - Rocky Mountain Spotted Fever Chlamydia - Eye or venereal disease Spirochaetes - Borrealia = Lyme Disease and Treponema = Syphilis (Huge Spiral cells, flexible) |
|
|
Archaea
|
Ancient, not considered true bacteria
Cell wall has no peptidoglycan Simpler than bacteria -Methanogens -Extremophiles: Thermophiles and Halophiles |
|
|
Bacterial Growth
|
Bacteria Reproduce by Cloning
- Binary Fission = splitting in two -Genome is copied, cell elongated, new cell wall and cell seperates |
|
|
Generation Time
|
Time b/w division => 30 mins
|
|
|
Exponential Growth
|
Explode in number when conditions are good
|
|
|
Bacterial Growth Curve in Optimal Conditions
|
Lag phase- Adaptation (turn genes on, produce enzymes)
Exponential Growth phase- bacteria doubling rapidly Maximum Stationary Phase- Carrying capacity reached Exponential Death Phase- halving => only strongly selected bacteria survive Population Crash = All cells die or Minimum Stationary Phase- A few hardy cells remain |
|
|
Viruses
|
Non-reproducing, non-metabolizing "particles"
Floating free= virion Obligate intracellular parasites |
|
|
Virus Three Designs
|
Eukaryotic Host cells:
1. Basic = unenveloped (naked) 2. Luxury model = enveloped Prokaryotic Host Cells: 3. Bacteriophages (phages) - Viruses that infect bacteria |
|
|
Required Parts of all Viruses
|
Nucleocapsid = Basic design
Protein capsid (shell) - composed of capsomere proteins |
|
|
Genetic Material
|
4 options:
-Single stranded DNA -Single stranded RNA -Double stranded DNA -Double stranded RNA |
|
|
Complex Viruses
|
Enveloped Design
-Outside nucleocapsid -Envelope: Phosopholipid bilayer (cell membrane of last host) -Glycoprotein spikes = peplomers |
|
|
Optional parts
|
Stabilizing proteins
Unique Enyzmes |
|
|
Virus Stabilizing proteins
|
Tegument or Matrix
|
|
|
Virus Unique enzymes
|
Reverse transcriptase- DNA from RNA template
Protease- cuts viral proteins Integrase- joins viral genes to host genome |
|
|
Bacteriophages (Phages)
|
Complex Capsid:
-Head -Tail -Tail fiberson baseplate -Lysozyme on baseplate -Digests peptidoglycan |
|
|
Viral Replication
|
Lytic cycle- virulent virus (immediate - 6 hours to 6 days)
Lysogenic cycle- temperate virus (may be delayed) |
|
|
Lytic Life Cycle: Step 1
|
Attachment (adhesion)
- Receptor protein on host cell surface -Virus binds to receptor proteins by ligand proteins: Phage: tail fibers Animal viral attachment: -Naked: capsomeres -Enveloped: peplomers |
|
|
Lytic Life Cycle: Step 2
|
Penetration
-Genetic material enters cytoplasm: -Phage: Lysoyzme and contraction of tail -Capsid remains outside Naked: 1. Phagocytosis- Uncoating in cytoplasm 2. Direct Entry Enveloped: 1. Fusion of enveloped and cell membrane 2. Phagocytosis (both-uncoating in cytoplasm) 3. Direct Entry |
|
|
Lytic Life Cycle: Step 3
|
Host genome shut down - may deteriorate (phage, some animal viruses)
Genome of virus directs all cell activities: -Stops normal cell activity -Produces viral parts: 1. Genome copies 2. Proteins - capsomeres |
