Exam 1 Flashcards
1
Q
Microorganisms/Microbes
A
very small organism too small to see (some parasites and fungi are visible to naked eye)
2
Q
Pasteurization
A
a process used to kill microorganisms responsible for spoilage (uses heat)
3
Q
Fermentation
A
process that uses bacteria, mold, or yeast to convert sugars (carbohydrates) to alcohol, gases, and organic acids
- people may have learned about it by accident (expired milk)
4
Q
Fermented foods/beverages include:
A
beer, wine, bread, yogurt, cheese
5
Q
Saccharomyces cerevisiae
A
yeast responsible for making bread rise
6
Q
Earliest examples of urban sanitation
A
the cities had complex networks of wells, baths, and drainage systems that stored fresh water and carried waste away. About two thousand years later, people in the ancient Greek civilization attributed disease to bad air, mal’aria, which they called “miasmatic odors.” They developed hygiene practices that built on this idea. In Rome, they built aqueducts, which brought fresh water into the city, and a giant sewer, the Cloaca Maxima, which carried waste away and into the river Tiber
7
Q
Hippocrates
A
Greek physician, father of western medicine
believed that disease had natural (not supernatural causes)
8
Q
Thucydides
A
- father of scientific history
- Introduced an early understanding of immunity after realizing that survivors of Athenian plague did not get reinfected with the disease
9
Q
Marcus Terentius Varro:
A
- one of the first to propose the concept that things we cannot see can cause disease
- “ certain minute creatures… which cannot be seen by the eye”
10
Q
Abū Bakr al-Rāzī:
A
- developed experimental methods to test various aspects of medicine
- For example, hung raw meat around the city to build hospitals in places where the meat took longest to rot
- First to distinguished, measles, and smallpox
11
Q
Ibn Sina
A
credited with advancing the practice of isolating people who were sick, laying foundation for quarantine methods
12
Q
Antonie van Leeuwenhoek:
A
- Father of microbiology
- first to develop a lens powerful enough to view microbes
- First to observe live cells using simple microscope
- He was able to observe live single celled organism which he described as “animalcules” or “wee little beasties” swimming in rain water
13
Q
Louis Pasteur:
A
- showed that individual microbial strains had unique properties
- Demonstrated that fermentation is caused by microorganisms
- Invented pasteurization
- Developed vaccines for treatment of diseases, including rabies
- SWAN NECK FLASKS disproved spontaneous generation
14
Q
Robert Koch
A
- first to demonstrate the connection between a single, isolated microbe, and a known human disease
- for example, he discovered the bacteria that causes anthrax (Bacillus Anthracis), cholera (Vibrio cholera), and tuberculosis (Mycobacterium tuberculosis)
15
Q
Carolus Linnaeus:
A
- most famous early taxonomist
- proposed the Linnaean taxonomy (a system of categories and naming organisms using a standard format)
- In his tree of life he divided the natural world into animals and plants
- invented binomial nomenclature
16
Q
Ernst Haeckel:
A
proposed another kingdom, Protista for unicellular organisms
Later proposed a fourth kingdom, Monera, for unicellular organisms, whose cells lack nuclei, like bacteria
His tree of life contained: Plants, Protista, Animals, and Monera
17
Q
Robert Whittaker:
A
- proposed adding a fifth kingdom - Fungi - in his tree of life
- tree of life contained: plants, Protista, animals, monera, and fungi
- Proposed a level of categorization above the kingdom level, known as the empire or super kingdom level, this distinguish between organisms that have membrane bound nuclei in their cell (eukaryotes) and those that do not (prokaryotes)
18
Q
Galileo Galilei
A
used a compound microscope to examine insect parts
19
Q
Robert Hooke
A
first, to observe cells by observing a sample of cork through his microscope (they were dead)
20
Q
Taxonomy
A
the classification, description, identification, and naming of living organisms
21
Q
Levels of categorization:
A
kingdom, phylum, class, order, family, genus, and species
22
Q
What is the most basic taxonomic unit?
A
Species
23
Q
Classification
A
the practice of organizing organisms into different groups based on their shared characteristics
24
Q
Phylogenetic Tree of Life
A
(contains the 3 domains) does not rely on observable characteristics that can often be subjective, instead relies heavily on comparing the nucleic acids or proteins from different organisms
25
Binomial Nomenclature:
- Two word naming system for identifying organisms by genus and specific epithet
- For example, humans are in the genus Homo and have a specific epithet name sapiens
binomial nomenclature: Homo sapiens
- The genus (first part) is always capitalized
- Followed by the specific epithet name, which is not capitalized
- Both names are italicized
26
Abbreviation for Binomial Nomenclature:
- First initial of the genus name, followed by a period and the full name of the species
- For example, the bacterium Escherichia coli is shortened to E. coli
27
3 major domains (proposed by Woese and Fox)
Bacteria, Archaea, Eukarya
28
Bacteria Domain
- contains prokaryotic organisms (their cells lack a nucleus)
- found nearly everywhere
- Most are harmless/helpful others are pathogens
- Cell walls contain peptidoglycan
- Often described in terms of their general shape (coccus, bacillus, vibrio, coccobacillus, spirillum, spirochete)
- Some are photosynthetic, others are non-photosynthetic
29
Archaea Domain,
- contains prokaryotic organisms (their cells lack a nucleus)
- Unicellular organisms
- Cell walls DO NOT CONTAIN PEPTIDOGLYCAN, instead psuedopeptidodogylocan
- Found almost everywhere, even in extreme environments
- None have been shown to be pathogen (causing disease)
30
Eukarya Domain
- Contains eukaryotic organisms (their cells do have a nucleus)
- Contains the kingdoms: protists, fungi, plants, animals
31
Characteristics of each kingdom, coming under eukaryotes
Protists
- informal grouping of eukaryotes that are not plants, animals, or fungi
- Includes some algae
- Cell wall made of cellulose
- All protozoa are examples of protists (protozoa or the backbone of many food webs because they provide nutrients for other organisms)
Fungi
- Not photosynthetic
- Have chitin cell wall
- Yeast (unicellular)
- Mold - play role in decomposition, often used to make pharmaceuticals (medicine)
Animals
- have no cell wall
Plants
- have a cellulose cell wall
32
Helminths
multicellular parasitic worms
33
Characteristics of viruses
- Acellular (not composed of cells)
- Do not fall within any of the three domains (Bacteria, Archaea, Eukarya)
- Consists of proteins and genetic material - either DNA or RNA - but never both
- Can infect all types of cells
- Not all viruses cause diseases
34
Microbiology
the study of microorganisms
35
Mycology
study of fungi
36
Immunology
study of the immune system
37
How much must an object measure to be visible without a microscope?
100 micrometers (ųm)
38
What are the two features common for all living cells?
Cell membrane and genetic material (DNA)
39
Difference between prokaryotes and eukaryotes
eukaryotes have a nucleus
Prokaryotes lack a nucleus
40
Difference between the domain bacteria and archaea (Which are both prokaryotes)
Bacteria has peptidoglycan cell, while archaea does not and is instead composed of pseudo marine
41
What are animal like protest called? What are plant like protest called?
protozoa and algae
42
What is the use of oil immersion lens?
To improve resolution by reducing the refraction
43
Reflection
occurs when a wave bounces off a material
44
Absorbance
occurs when a material captures the energy of a light wave
45
Transmission
occurs when a wave travels through a material, like light through glass (usually occurs when material is thinner or more transparent/less opaque)
46
Refraction
- the most important behavior, exhibited by light waves
- the bending of light or sound waves as they pass through different materials or substances
47
Dispersion
Separation of colors
48
Resolution
the ability to tell that two separate points or objects are separate
factors affecting resolution include wavelength and numerical aperture (lenses ability to gather light)
shorter wavelength = better resolution and higher energy
49
Total magnification
= ocular magnification x Objective magnification
50
Magnification of objective lenses:
Scanning: 4X
Low power: 10 X
High power: 40 X
Oil immersion: 100 X
51
Parts of a Compound Microscope & functions 12 parts
Eye piece (ocular lense)
- First set of Lenses
- what you look through
Revolving nose piece
- Holds multiple Objective lenses
Objective Lenses
- Second set of lenses
- Used to magnify the image of the specimen (4x, 10x, 40x, 100x, etc)
Coarse focus
- Larger knob
- Used to move the stage
Fine focus
- Small knob
- Used to focus image
Stage
- Where you keep the specimen on the slide in position
Illuminator
- Light source
Diaphragm
- Reduces/magnifies intensity of light
Condenser
- Third set of lenses
Mechanical stage
- ???
XY Mechanical stage knobs
- Used to move slide
Rheostat
- to adjust light intensity
52
What types of electron microscope?
Transmission electron microscope:
- uses electron beams that pass through a specimen to visualize small images
- Useful to observe, small, then specimens such as tissue sections and subcellular structures
- Well defined
Scanning electron microscope:
- Uses electron beams to visualize surfaces
- Useful to observe the three dimensional surface details of specimens
- 3D image
53
Differences between light and electron microscope
- Source of energy: Light energy for light microscopes and beam of electrons for electron microscopes
- Objectives: Glass objectives for light microscopes and electromagnets for electron microscopes
- Oculars: Ocular are present and light microscopes, and no ocular for electron microscope
- Medium: Air is the medium inside the light microscope and vacuum inside electron microscope
54
Staining techniques
simple, differential and special stains (importance of each stain)
Simple
- A single dye is used
- All organisms will appear the same color even if sample contains more than one organism
Differential
- Uses multiple stains on one slide
- Examples: gram stain, acid fast stain
Special
- Staining “special” structures
- Example: Capsule staining, Flagella staining, endospore staining
55
Gram stain: purpose and know the steps
* A type of differential staining technique
* Used to distinguish cells by cell wall type (Gram-negative and gram-positive)
* Hans Christian Gram
* 4 Step Process
- Step 1: Crystal Violet (primary stain)
- Step 2: Iodine (mordant)
- Step 3: Alcohol (decolonized)
- Step 4: Safranin (counter stain)
56
Gram Stain Process: Gram +
Step 1: Crystal violet - stains the cell purple or blue
Step 2: Iodine - Cells remain purple or blue
Step 3: Gram positive cells remain purple or blue
Step 4: Gram-positive cells remain purple or blue
57
Gram Stain Process: Gram (-)
Step 1: Crystal violet - stains the cell purple or blue
Step 2: Iodine - Cells remain purple or blue
Step 3: alcohol - Gram-negative cells become colorless
Step 4: Safranin - Gram-negative cells become pink or red
58
Acid fast stain
- differential staining technique
- Differentiates two types of gram-positive cells: those that have waxy my colic acid and their cell walls and those that do not
- Or used to distinguish acid fast bacteria, such as Mycobacterium tuberculosis, from non-acid fast cells
59
Electromagnetic spectrum and color
- Color red has low frequency, color violet has the highest frequency
60
What do you mean by “fixing”
- heat fixing or chemical fixing
- Purpose is to kill the cells and to make them adhere to the slide
61
What type of staining technique was used to find tuberculosis?
Acid fast staining
62
Miasma Theory
an outdated medical hypothesis that proposed that diseases are caused by poisonous vapors or "miasmas" in the air
63
Endosymbiotic Theory
mitochondria and chloroplasts are derived from the uptake of bacteria
- proposed by Lynn Margulis
64
What organelles are thought to be formed inside the eukaryotic cell based on the Endosymbiotic theory? what is the evidence?
mitochondria and chloroplast
Their size and shape both resemble bacteria, both have 70 S ribosomes, both contain circular DNA and divide independently of the host
65
What are the only organelles in prokaryotes?
Ribosomes (70s)
66
Spontaneous Generation
articulated by Aristotle
The notion that life can arise from nonliving matter
67
Francesco Redi
performed an experiment in 1668 that was one of the first to refuse the idea that maggots spontaneously generate on meat left out in the open air
Concluded that maggots could only form when flies were allowed to lay eggs in the meat, and that the maggots were offspring of flies, not the product of spontaneous generation
68
John Needham
- argued in favor of spontaneous generation
- He briefly boiled the broth infused with plant or animal matter, hoping to kill all pre-existing microbes, he then sealed the flasks, after a few days, he observed that the broth contain numerous microscopic creatures
- He likely did not boil the broth enough to kill all pre-existing microbes
69
Lazzaro Spallanzani
- performed experiments against Needhams claim of spontaneous generation
70
Aristotle
earliest recorded scholar to articulate the theory of spontaneous generation
71
Schleidan and Schwann
Schleidan observed plant tissue
Shwann observed animal tissue
72
Robert Remak and Rudolf Virchow
published convincing evidence that cells are derived from other cells as a result of cell division
Cumulated what we know now as the modern cell theory
73
Robert Brown
first To describe observations of nuclei observed in plant cells
74
Ignaz Semmelweis
introduce the importance of handwashing to prevent transfer of disease between patients by physicians
75
Joseph Lister
First to use chemical disinfectant on live tissue (Listerine)
76
John Snow
father of epidemiology
Traced down the origin of cholera and found that it came from dirty water
77
Biogenesis
Life comes from pre-existing life, proved by Louis pasteur Swan neck experiment
78
Cell theory
all living organisms are made up of cells, The cell is the fundamental unit of life
79
Germ theory
proposed by Girolamo Fracastoro
States that diseases may result from microbial infection
80
Prokaryotic cells structure
* cell membrane
* chromosome DNA that is concentrated in the nucleoid
* ribosomes - THE ONLY ORGANELLE
* cell wall
* some prokaryotic cells may also have flagella, pilli, fimbriae, and capsules, inclusions
81
Plasma membrane structure (in prokaryotic cell)
composed of phospholipid bilayer
82
Fimbriae
helps bacteria stick
83
Pilli
-looks like long and thin hair
- used for sexual reproduction
84
Flagella
-helps propel/ the bacteria
-thicker than pilli
-flagillant protein
85
Animal cells do not have:
Do not have a cell wall or chloroplasts
86
Different arrangement of flagella in bacteria
monotrichous: One string on one side
lophotrichous: One string on each side
amphitrichous: Multiple strings on one side
peritrichous: multiple strings all around
87
Cell walls of gram-negative
- thin peptidoglycan sandwiched between inner and outer cell membranes (3 layers of cell wall)
- more complex
- outer layer is toxic (lippopolyscharrides)
88
Cell walls of gram-positive
- thick peptidoglycan
- teichoic acid
89
Bacteria Cell wall structure
contains peptidoglycan
90
peptidoglycan structure
* composed of polymers NAM and NAG
In gram negative bacteria there is a direct link
In gram positive bacteria there is penta peptide and tetra peptide
91
Membrane transport mechanisms in prokaryotes and eukaryotes
1: Passive Transport: (no ATP is required) material moves from a high concentration to a low concentration
- simple diffusion: movement of molecules from regions of high concentration to regions of low concentration until an equilibrium is reached
- facilitated diffusion: movement of molecules from high concentration to low concentration through a membrane protein
- osmosis: water molecules pass through a semipermeable membrane from an area of high water concentration to an area of low water concentration
2: Active transport: molecules are moved against concentration gradient (ATP is required)
92
Structures external to the cell wall: Glycocalyx
Two types:
Capsule - neatly organized and firmly attached
Slime layer - unorganized and loose
93
Tonicity
the ability of a solution to change the volume of a cell by affecting osmosis
94
Cells without cell wall and hypertonic solution will…
Lose water and shrink (crenation)
95
Cells without cell wall in hypotonic solution will…
Gain water and breakdown/burst (lyses)
96
Cells with cell wall in hypertonic solution will get…
plasmolyzed
97
Cells with cell wall and hypotonic solution will get…
“turgent” or swelled up
98
Organelles of the Endo membrane system
- nuclear envelope
- endoplasmic reticulum
- Golgi apparatus
- lysosomes
- vesicles
99
Organelles which are not included in the Endomembrane system
Mitochondria, chloroplast, peroxisomes
100
Function of golgi apparatus
Sorting and packaging everything into vesicles
‘’Post office” of the cell
101
Smooth ER
Makes lipids, steroid hormones, lysosomes
Acts as detoxifying organell
102
Mitochondria
Power house of cell, has 2 membranes (inner & outer), atp production
103
Centriole
Organization of microtubioles
104
Symbiosis
any interaction between different species within a community
105
Types of Symbiotic Relationships: (5)
Mutualism - both populations are benefitted
-Example: E. coli
Amensalism - one population is harmed, the other is unaffected
-Example: L. sericata
Commensalism - one population is benefitted the other is unaffected
-S. epidermidis
Neutralism - both populations are unaffected
-B. anthracis and endospores
Parasitism - one population is benefitted, the other is harmed
-any human bacterial infection
106
Proteobacteria
from the mythical Greek god Proteus, who could assume many shapes
Know the important bacteria mention in lecture regarding the associations
107
Know the classification scheme of the domain bacteria into kingdoms and phyla
Domain: bacteria —> kingdom: gram positive < phylum: low g+c or high g+c
Domain: bacteria —> kingdom: gram negative < phylum: proteobacteria and nonproteobacteria
108
Gram negative:
Largest taxonomic group of bacteria
109
5 classes of Proteobacteria
Alphaproteobacteria
Betaproteobacteria
Gammaproteobacteria
Deltaproteobacteria
Epsilonproteobacteria
110
Alphaproteobacteria
- oligotroph (require low nutrition)
- they are intracellular obligate parasites
- organism: Rickettsia (Rocky Mountain disease) due to ticks
- organism: Chlamydia Trachomatis (common among college student, causes STI and trachoma)
111
Betaproteobacteria
- eutrophs/copiotrophs (require lots of nutrients)
- organism: N. meningitidis: causes meningitis
- organism: N. gonorrhoeae: causes STI gonorrhea
- organism: Bordetella pertussis: whooping cough
112
Gammaproteobacteria
- most diverse and largest class of Proteobacteria
- Organism: Vibrio cholerae - diahreah & dehydration
- Organism: Vibrio parahaemolyticus - causes gastroenteritis
- Organism: Vibrio vulnificus - cause cellulitis and skin eating bacteria
- Organism: pseudomonas aeruginosa (UTI)
- Organism: Haemophilus influenzae: respiratory illness
- Enterics: bacteria that live in intestinal tract
- Coliforms: able to ferment lactose completely (E. coli)
- Non-coliforms: can not or incompletely ferment lactose (salmonella, shigella, yersinia pestis)
113
Deltaproteobacteria
bacteria under this are predators of other bacteria
example: Bdellovibrio bacteriovorus
114
Epsilonproteobacteria
- microaerophilic (only require small amounts of oxygen)
- smallest class of gram negative proteobacteria
- Campylobacter
- Helicobacter: causes stomach ulcers or stomach cancers
115
Phylum Non-Proteobacteria (under kingdom gram negative)
* 1st Class: Spirochetes - long, spiral shaped, very thin, very difficult to culture, highly motile, use axial filament to propel themselves
* 2nd Class: CFB
- Cytophaga - motile aquatic bacteria that glide
- Fusobacteria - inhabit the human mouth and may cause severe infectious diseases
- Bacteroides - Largest genus of the CFB groups (PREVALENT INHABITANTS OF THE HUMAN LARGE INTESTINE) is 30% of the normal microbiota in the human gut
* 3rd Class: Photobacteria/Phototrophic Bacteria (large and diverse group, use solar energy to synthesize ATP through photosynthesis
- Oxygenic - produce oxygen during photosynthesis (Cyanobacteria)
- Anoxygenic - (green/purple sulfur and nonsulfur bacteria)
116
Photosynthesizers
Oxygenic under non-proteobacteria
117
Gram-positive
- thick peptidoglycan cell wall
- remain purple in gram staining
- 2 Phyla : Actinobacteria (high G+C) and Bacilli (low G+C)
118
Phylum High G+C (under kingdom gram positive)
- high G+C, aka Actinobacteria, they have more than 50% guanine and cytosine nucleotides in their DNA
* Mycobacteria
- Mycobacterium tuberculosis
- M. leprae - causes Hansen’s disease or leprosy
- Corynebacterium diphtheria
- Gardnerella vaginalis
119
Phylum Low G+C (under kingdom gram positive)
- low G+C, aka Bacilli, they have less than 50% guanine and cytosine nucleotides in their DNA
* Clostridia - produce endospore, are anaerobes (die in oxygen)
* streptococcus - chain of cocci, they are hemolytic, breakdown red blood cells
* lactobacillus - maintains acid environment in vaginal canal
staphylococcus - skin infection
120
121
Answer to one
Polysaccharides
Teichioc acid
