Microbiology Lecture Exam 1
(T/F) All bacteria have cell walls
False
(T/F) Autotrophs only use light for energy
False
T/F eukaryotes and prokaryptes evolved independently
False
What counting methods can differentiate between live and dead cells?
flow cytometer
Lophotrichous (polar)
small bunches or tuffs
Halophile
"salt-loving" archaea that live in environments that have very high salt concentrations
asexual life cycle
-fungi are classified by their asexual spores -sporangiospores and conidospores
pili (sex pili)
-special type of fimbria -fimbriae<pili<flagella -only a few per cell -sex pilus/transfer DNA from one cell to another -some pili can provide motility -controlled genetically in G bacteria
Select characteristics exhibited by most bacteria and archaea to test your understanding of the differences between these microorganisms and eukaryotic organisms. 1. DNA 2.Nucleus 3. Golgi Body 4. Ribosomes 5. Cell wall composed of unique lipids and carbohydrates
1. DNA 4. Ribosomes 5. Cell wall composed of unique lipids & carbohydrates
Describe ways in which eukaryotic flagella are different than prokaryotic flagella
1.10x thicker 2.structurally more complex 3.covered by an extension of the cell membrane
Fermentation of a glucose molecule has the potential to produce a net number of ____ ATPs
2
Which of the following are true regarding spontaneous generation? Check all that apply. 1. It was definitively disproven by Francesco Redi. 2. Louis Pasteur designed an experiment with swan-necked flasks that disproved this theory once and for all. 3.This theory was based on idea of abiogenesis. 4. The meat maggot experiment indicated that the concept of abiogenesis was likely true.
2. Louis Pasteur designed an experiment with swan-necked flasks that disproved this theory once and for all. 3.This theory was based on idea of abiogenesis.
ATP synthase complexes can generate ____ATP for each NADH that enters electorn transport
3
Morphology and arrangement of cells
3 basic shapes coccus-round bacillus-oval spirillium-spiral diplo-2 tetrads-groups of four staphylo-grapes strepto-chains of a few to a hundred sarcina-cube packet of 8,16 or more
Choose the statement or characteristic that best describes the current taxonomic system. 5 kingdoms as the highest levels of taxonomy First division is based on prokaryote vs eukaryote with all prokaryotes being very genetically distinct from the eukaryotes 3 distinct cell lines called domains as the highest taxonomic category Organisms divided first into groups of plants, animals, and microorganisms
3 distinct cell lines called domains as the highest taxonomic category
Complete oxidation of glucose in aerobic respiration can yeild a net output of ______ ATP
38
Total yield from glycolysis, Krebs cycle and electron transport
38 ATP
Describe the difference between nematodes, cestodes, trematodes
<<nematodes(roundworms) - non segmented bodies, complete digestive system, separate sexes >>cestodes(tapeworms) - segmented bodies, hermaphroditic, absorb nutrients << trematodes(flukeworms): non-segmented, leaf shape. primitive gut, hermaphroditic mostly
fermentation
A catabolic process that makes a limited amount of ATP from glucose without an electron transport chain and that produces a characteristic end product, such as ethyl alcohol or lactic acid.
Methanogens
A group of archaebacteria that produce methane as a by product of their metabolism.
Commensalism
A relationship between two organisms in which one organism benefits and the other is unaffected
parasitism
A relationship between two organisms of different species where one benefits and the other is harmed
Electron Transport Chain (ETC)
A sequence of electron carrier molecules (membrane proteins) that shuttle electrons during the redox reactions that release energy used to make ATP.
A Product or products of glycolysis is/are ATP H20 CO2 both a&B
ATP
What are the three domains of the Woese-Fox system of classification
Archae, bacteria, eukaryote
Hyperthermophiles
Archaea growing about 80 degrees celcius and some above 100 degrees celcius
Three Domains
Bacteria, Archaea, Eukarya
What is the impact of microorganisms on environment (photosynthesis)
Bacteria= ubiquitous bacteria & algae more than 70% of earth photosynthesis majority of the oxygen to the atmosphere
Describe the differences between capsules and biofilms.
Biolfilms are groups of microbes colonize on the surfaces long term indwelling to protect surface from pathogenic bacteria, and capsules fromed by pathogenic bacteria to coat there surface and protect from white blood cells.
binomial nomenclature
Classification system in which each species is assigned a two-part scientific name Genus & species G. species (italicized)
Inspection
Cultures are observed for growth characteristics
How and why have causes of death changed over time
Deaths due to disease have decreased due to immunizations, yet self causes diseases have increased
Robert Koch
Developed the culture plate method to identify pathogens
What do we call a collection of signs and symptoms that alter homeostasis in a host in a negative way?
Disease
Describe three functions of the cytoplasmic membrane
Energy reactions Nutrient processing Synthesis Transport
Characteristics of fungi
Eukaryotes - Have a distinct nucleus chitin cell walls Use organic chemicals for energy Fungi cannot carry out photosynthesis Can reproduce sexually or asexually. Most typical fungi are molds - Multicellular, consisting of masses of myclia which are composed of filaments called hyphae.
Characteristics of protozoa
Eukaryotic microbes Move by pseudopods (false feet), flagella or cilia. Can reproduce asexually or sexually Varieties of shapes Live either as free entities or as parasites Absorb or ingest organic chemicals
Microorganisms have adapted to nearly every environment through the process of ______. recombinant DNA technology ubiquity evolution bioremediatio
Evolution
True or False Archaea are known to cause disease
FALSE Archaea are NOT known to cause disease (not relevant to the human health)
(T/F) Only two of the main types of microorganisms are found in or on the normal healthy human body.
False
(T/F) Plasmids are vital to the meta
False
(T/F) The average generation time of most bacteria under optimum conditions is 24-48 hours
False. It is 30-60 min.
To which division of bacteria does E. coli belong? -Tenericutes -Gracilicutes -Firmicutes -Mendosicutes
Gracilicutes
Difference between gram positive and gram negative cell well
Gram positive has a large peptidoglycan cell wall- this is what the stain sticks to during the process
Motility is best observed with a a. hanging drop preparation b. negative stain c. streak plate d. flagellar stain
Hanging drop presentation
Identification
Identification of the species
Steps of the Scientific Method
Identify problem, Form Hypothesis, Collect Data, Analyze Data, Form Conclusions
Describe advantages of protozoans producing cysts
Important factor in spread of disease. Formed when conditions become unfavorable for growth and feeding...the cell wall (cuticle) is tough.
How is the definition of species different for bacteria than for animals
In animals a species is a distinct type of organism that can produce viable offspring only when it mates with others of its own kind. This definition does not work for bacteria and archae primarily because they do not exhibit a typical mode of sexual reproduction
Aseptic techniques were developed by
Joesph Lister
Catabolism is a form of metabolism in which ____ molecules are converted into ____ molecules.
Large, small
lipid catabolism
Lipids are hydrolyzed into glycerol and fatty acids
The microorganisms that live in or on the human body are called the ______. archaea prokaryotes microbiome recombinant
Microbiome
Characteristic of viruses
Most can only be seen with an electron microscope due to how small they are. Simple structure - Core made up of either DNA or RNA, core is surrounded by a protein coat - coat may be enclosed in a lipid envelope. Can only reproduce when they are in a living host. Without a host, the virus is inert Acellular
At what stage of growth are bacteria best for testing biochemical reactions? At what phase are they most susceptible to antibiotics
Most susceptible to antibiotics- log phase
Characteristics of helminths
Multicellular eukaryotic animals Specialized to live in hosts May lack digestive system Reduced nervous system Reduced or lacking locomotion Complex reproductive system
_____________ evolved from primitive cells that became engulfed or trapped in larger cells with elementary membranes
Organelles
Darkly stained granules are connected crystals of _____ that are found in _____
PO4, Corynebacterium
Characteristics of algae
Photosynthetic eukaryotes Cellulose cell walls Sexual and asexual reproductive forms Produce molecular oxygen and organic compounds
regulated enzymes
Production is turned on (induced) or turned off (repressed) in response to changes in concentration of substrate
Characteristics of Archae
Prokaryotes Lack peptidoglycan but do have cell walls Found in extreme environments: methanogens - produce methane as a waste product. Extreme halophiles - live in extremely salty environments Extreme thermophiles - live in extremely hot sulfurous environments
Order the following choices to reflect the relative sizes of microorganisms as compared to each other and other cells, ranging from the largest to the smallest. Red Blood Cell Most Bacteria Viruses Reproductive structure of bread mold
Reproductive Structure of Bread Mold Red Blood Cell Most Bacteria Viruses
In helminths, the most developed organ system is the ________ system.
Reproductive tract
anaerobic respiration
Respiration in the absence of oxygen. This produces lactic acid. less efficient than aerobic
A ______is a type of fungus that derives nutrients from dead or decaying material
Saprobes
Isolation
Separation one species from another
Characteristics of bacteria
Single celled Organisms Prokaryotes Peptidoglycan cell walls Reproduce by binary fission Bacteria move by using a flagella For energy: Use organic or inorganic chemicals or photosynthesis
____are asexual spores contained in a saclike head
Sporangiospores
Describe the steps of endospore formation
Sporulation: 1. asymmetrical cell dicision 2. engulfment of spore by mother cell 3. cortex formation>>forms thick coat of peptidoglycan while inside mother cell 4. coat, Ca2+, SASPs, dipicolinic acid 5. water loss, maturation, cell lysis 6-7. germination
Krebs Cycle (Citric Acid Cycle)
The Krebs Cycle, also known as the citric acid cycle, takes place in the matrix of the mitochondria. In the Krebs Cycle, each of the two acetyl coenzyme A molecules enter the cycle and combine with oxaloacetate to form citric acid, which then loses two carbons as carbon dioxide. The cycle is now ready to begin again with the second Acetyl CoA. For each Acetyl CoA, the Krebs Cycle produces 1 ATP, 3 NADH, and 1 FADH2. doesn't require CO2
dismutase
The enzyme that breaks down the free radical that causes tissue damage
Inoculation
The introduction of a pathogen or antigen into a living organism to stimulate the production of antibodies.
The three cell types discussed, eukaryotes, archaea, and bacteria, all derived from ______
The last universal common ancestor
Describe how the outer membrane of gram-negative contributes to disease symptoms.
The outer membrane of a gram-negative contributes to disease symptoms because it contains Lipopolysaccharide which is an endotoxin which stimulates fever and shock reactants.
Anabolism
The sysnthesis of complex molecules in living organisms from simpler ones together with the storage of energy
Why are helminths (worms) considered in the study of microbiology?
They are transmitted similarly to bacterial diseases and the human body responds to them in the same way as it responds to bacterial diseases
The feeding, motile stage of protozoans is the
Trophozoite
(T/F) pathogenic fungi require a host to complete their life cycle
True
(T/F) Microscopic organisms produce more oxygen than plants
True
(T/F) Generally, all bacteria of the same species should have same shape and arrangement
True (morphology)
Microbial dimensions small to large
Virus bacteria yeast red blood cell protozoan
Among the types of microorganisms, the ______ are noncellular.
Viruses
Eukaryotic cells are larger than bacterial or archaeal cells; all cells are larger than macromolecules. Where do viruses fit on this scale?
Viruses are smaller than bacterial or archaeal cells, but larger than macromolecules.
Resolution is ___ with a longer wavelength of light. a. improved b. worsened c. not changed d. not possible
Worsened
What is the difference between a "run" and a "tumble"?
a run is going in a smooth counterclockwise motion but when it tumbles it stops, changes course, and reverses directions
pH requirements for affecting growth
acidophiles- grow best at low ph <6 Neutrophiles- grow best bw pH 6-8 Alkalinophile- grow best at high pH >8
Which of the following is not found in all bacteria cells? -cytoplasmic membrane -a nucleoid -ribosomes -actin-like cytoskeleton
actin like cytoskeleton
An apoenzyme is where the _____ is located
active site
constitutive enzymes
always present and in relatively constant amounts
Carbohydrate catabolism
amylase- break downs tarch into glucose
The source of the necessary elements of life is
an inorganic environmental reservoir
What is measured to determine serotype?
antibody responses
Most helminth infections -are localized to one site in the body -spread through major systems of the body -develop within the spleen -develop within the liver
are localized to one site in the body
Psychrophiles would be expected to grow
at refrigeration temperatures
Bacteria & archae vs eukaryotes
bacteria can reproduce, metabolize, and nutrient processing bacteria does not wind DNA and archaea does bacteria and archaea have nuclear material free in cytoplasm eukaryotes have a nucles and wind with DNA bacteria cell wall made up of peptidoglycan
How are bacterial ribosomes different than eukaryotic ribosomes?
bacterial ribosomes are 70S and eukaryotic ribosomes are 80S
How are protozoans classified?
by how they move
subgroups
cell shape arrangements oxygen usage (aerobic, anaerobic, facultative)
quorum sensing
cells are stimulated to release chemicals as the population grows to monitor its size
pyruvic acid
central metabolite for many biological processes
The category that ONLY contains bacteria and archaea is _________.
chemautotrphs
A _____ required organic molecules for carbon and energy
chemoheterotroph
3 shapes of bacteria
coccus, bacillus, spirillum
Psychrophiles
cold-loving microbes
In a viable plate count, each ____ represents a ____ from the sample population.
colony, cell
Cells characteristics
contain ribosomes always have plasma membrane may havea cell wall
aerobic respiration
converts glucose to C)2 and allows the cell to recover signigficant amounts of energy glycolysis, krebs cycle and ETC
AI-2 (autoinducer 2)
cross species talk
What part of the bacterial cell is analyzed to determine evolutionary relatedness
determined through comparison of nitrogen bases in rRNA this is used because Tend to remain stable in their nucleic acid content over long periods and Any major differences in the signature sequence indicates distance in ancestry
The papers that Pasteur published regarding the germ theory of ________ and disproving the __________________ were read by his contemporary Joseph Lister, a surgeon battling high post-surgical mortality in his patients.
disease ; theory of spontaneous generation
Superoxide ion is toxic to strict anaerobes because they lack
dismutase
parasitic helminths reproduce with -spores -eggs and sperm -mitosis -cysts -all of these
eggs and sperm
induction control
enzymes appear induced only when suitable substrates are present inverse of enzyme represion
(T/F) Eukaryotic cell walls perform a similar function to prokaryotic cell walls
eukaryotic cell walls are rigid, provide structural support,shape and have different chemical composition than bacterial cell walls
To difest cellulose in its environment, a fungus produces
exoenzyme
(T/F) fungal spores have a tough outer coating that allows them to survive in extreme conditions
false
(T/F) Some helminths produce millions of eggs to overcome a high mortality rate of ova
false- they do not have a high mortality rate
Name the three parts of a bacterial flagellum.
filament, hook, basal body
amphitrichous (polar)
flagel
petrichous
flagella are dispersed randomly over the surface of the cell
Sporangiospores
formed by successive cleavages within a sporangium (spore bearing sac
Conidospores
free spores not enclosed by a spore-bearing sac
superficial mycoses
fungi colonize the hair, skin, or nails and infect only the surface layers
The cell wall is found in which eukaryotes -fungi -algae -protozoa -a and b
fungia and algae
Glycocalyces
gelatinous, sticky substance surrounding outside of the cell polysaccharides or polypeptides 2 types can accumulate, capsule or slime layer biofilms
Viruses Characteristics
genome may be exclusively RNA are obligate parasites outer layer is predominately protein
A scientist who studies the influence of microbes in the formation of caves is called a(n) ______.
geomicrobiologist
divisions
gracilicutes-gram neg cell walls, thin firmicutes-gram pos cell walls, thick and strong tenericutes-lack a cell wall, soft mendosicutes-archaea
AIP (autoinducing peptide)
gram + some AIP's differ by amino acid
AHL (autoinducer homoserine lactone)
gram - positive feedback 180 genes during reg metabolism 600 genes in high cell density
Pili are tubular shafts in ____bacteria that serve as a means of _____.
gram negative, genetic exchange
Mycoplasma
groups of pathogenic bacteria membrane is stabilized by sterols and is resistant to lysis ex: chlamydia
Some helminths are ________, having both male and female organs.
hermaphrodite
Energy is carried from catabolic to anabolic reactions in the form of
high energy ATP bonds
Lister had studied inflammation and suspected that wound sepsis was caused by an infectious agent in the air. Pasteur's work solidified his _________ so he began to use ___________ before performing an operation, drastically reducing the number of deaths in patients following surgery.
hypotheses ;phenol
Plasmodium
is a genus of unicellular eukaryotes that are obligate parasites of vertebrates and insects -life cycle involves development of blood feeding insect host which then injects parasites into a vertebrate host
Which of the following is true of passive transport
it requires a gradient
Place the four steps of the growth curve in the proper order: Log phase Death phase Lag phase Stationary phase
lag phase log phase stationary growth phase death phase
Mycobacterium
lipids (mycolic acid) in the cell wall increase survival ex:TB
A cell exposed to a hypertonic environment will ____ by osmosis.
lose water
Incubation
maintaining something at the most favorable temperature for its development
In 1857, Louis Pasteur discovered that specific organisms carry out chemical reactions and create ________ end-products such as alcohol and lactic acid.
metabolic
Chemotrophs can survive on _____ alone
minterals and CO2
Biofilms
mixed communities of different kinds of bacteria and other microbes ex: plaque
Complex stain
more than one dye is used
atrichous
no flagella
A real image is produced by the a. ocular b. objective c. condenser d. eye
objective
A real image is produced by the -ocular -objective -condenser -eye
objective
oxygen requirements affecting growth
obligate aerobe-essential has enzymes to detoxify facultative anaerobe-capable of growth in absence of O2 but prefers obligate anaerobe-O2 is deadly, can't detoxify aerotolerant anaerobes-can survive and grow to a limited extent in presence of O2
nonsymbiotic
organisms are free-living; relationships not required for survival synergism/members cooperate and share nutrients -antagoniam/some members are inhibited or destroyed by others
Symbiotic
organisms live in close nutritional relationships; required by one or both members
A pathogen would most accurately be described as a
parasite
All mature sporozoa are -parasitic -nonmotile -carried by vectors -both a and b
parasitic and nonmotile
Pasteur is also credited with the process of __________ which removes pathogens from consumable liquids, reducing _________ and subsequent illness.
pasteurization ; contamination
An organism that can synthesize all its required organic components from CO2 using energy from the sun is
photoautotroph
3 categories of media classification
physical state chemical composition functional type
Binary fission
prokaryotic cell division following enlargement of a cell to twice its minimum size
Both flagella and cilia are found primarily in -algae -protozoa -fungi -both a and c
protazoa
Protein catabolism
proteins break down in to amino acids and undergo a variety of conversions; products can enter glycolysis or kreb's cycle
phylogeny
represents the natural relatedness between groups of living thigns
Which of the following statements is true for ALL organisms
require inorganic nutrients
Flagella structure
responsible for movement long structures that extend beyond cell surface are not present on all bacteria filament, hook, and basal body
Osmotic pressure affecting growth
restricts organisms to certain environments requires high levels of salt- halophile best of solute concentration 3-12% halotolerant can tolerate solutes 1-7% non halophiles need very low concentration
Features of the nuclear envelope include -ribosomes -a double membrane structure -pores that allow communication with the cytoplasm b and c all of these
ribosomes double membrane structure pores that allow communication with the cytoplasm
saprobes vs. parasitic
saprobes feed primarily on organic detritus from dead organisms parasites derive nutrients from the cells and tissues of a host
A bacterial arrangement in packets of eight cells is described as a -micrococcus -diplococcus -tetrad -sarcina
sarcina
monotrichous (polar)
single flagellum at one pole
fimbriae
sticky, bristle like projections -used by bacteria to adhere to one another and to substance in environment -serve an important function in biofilms
repression
stops further synthesis of an enzyme somewhere along its pathway response time is longer than for feedback inhibition
Sexual Life cycle
strains of different mating types must meet 9hyohae or mycelium) for sexual spore formation -allow for genetic variation -usually microscopica
alcoholic fermentation
the anaerobic process by which yeasts and other microorganisms break down sugars to form carbon dioxide and ethanol
Almost all protozoa have a -locomotor organelle -cyst stage -pellicle -trophozoite stage
trophozoite stage
Yeasts are ____ fungi, and molds are ____ fungi.
unicellular, filamentous
simple stain
use of a single basic dye
Many coenzymes metals vitamins proteins substrates
vitamins
Resolution is _____ with a longer wavelength of light. -improved -worsened -not changed -not possible
worsened