BIOL 2261 Exam 1 Nguyen
How to calculate total magnification?
(ocular X objective) = total
Gram +
90% peptidoglycan layer, teichoic acids in cell wall, lipoteichoic acids attached to membrane lipids
Koch's postulates developed from his STUDY of __________?
Anthrax
What domains have pili?
Bacteria (Type IV) and Archaea
What domains have peptidoglycan?
Bacteria ONLY
What type of microscope allows you to see 3D?
DIC (no staining)
Penicillin are effective against...
Gram +
False
In an endospore, the protein coat forms a layer external to the exosporium.
nucleocapsid
In an enveloped virus, the part of the virus including the nucleic acid genome and the surrounding protein coat but not the envelope is called the
mother cell
In endospore formation, when DNA condenses and aligns itself in the center of the cell, the cell is called a(n) ______.
False
Like prokaryotic cells, most eukaryotic cells have an external cell wall.
What macromolecule produces the most ENERGY?
Lipid (lipid > carb > protein)
amphipathic
Lipids with polar and nonpolar ends are said to be
Diplococci
Pairs of spherical cells
Protein
RNA serves to convert the information stored in DNA to ________.
What species fixes N2 in symbiosis with leguminous plants?
Rhizobium sp.
What species is in symbiosis with cattle? (allows cattle to eat grass and break down cellulose in the grass)
Ruminococcus sp.
True
Some archaeal cells lack a cell wall.
True
Spirillum is a genus of spiral-shaped bacteria that move by flagella.
False
The Gram stain can only be performed on cultures grown in liquid media.
cell wall
The Gram stain of a bacterial cell is based on the chemical properties of its ________.
Resolution
The ability to distinguish between two separate structures that are very close to one another
Magnification
The apparent increase in size of an image
True
The endosymbiotic hypothesis is generally accepted as the origin of two eukaryotic organelles: mitochondria and chloroplasts.
Stroma
The formation of carbohydrate (CO2 fixation) in the dark reaction of photosynthesis, takes place in the
endotoxin
The lipopolysaccharide (LPS) that is found in the outer membrane of gram-negative bacteria is also known as
True
The membrane bound structure that contains the chromosomes of eukaryotes is called the nucleus.
What organism causes syphillus in humans?
Treponema pallidum
Polyphosphate
accumulations of inorganic phosphate
What type of microscope allows you to see CELL MOTILITY?
dark-field (no staining)
Bacteria and Eukarya
ester linkages
What is one way that microbes are genetically engineered?
human insulin (genetically engineered bacteria)... today engineered yeast is used to make insulin
Gram -
~10% peptidoglycan, nutrient transporter proteins and hydrolytic enzymes, LPS (lipopolysaccharide), Lipid A (endotoxin - released when bacteria dies), porins and TonB proteins in membrane to allow diffusion of molecules into periplasmic space
When was the light microscope invented?
1600s
Virion
A complete virus particle is called a
consist of a lipid monolayer
A feature unique to some archaeal plasma membranes is that they may
an archaeon
A newly discovered microorganism has a circular chromosome that is complexed with histones, but not enclosed within a membrane. The plasma membrane lipids include glycerol dietethers and diglycerol tetraethers. There are no mitochondria or chloroplasts, but the cells do contain 70s ribosomes. This microbe most likely is
The bacteria will become less virulent and will not be able to readily establish infection.
A strain of Neisseria gonorrhoeae has undergone a mutation and is no longer able to make pili. Predict the most likely outcome.
False
A temperate phage always lyses its host cell.
3 different types of active transport?
ABC (ATP-Binding Cassette) Systems, Secondary Active Transport, Group Translocation
Contrast
Ability to be distinguished from the surroundings
Pink Gram-positive and pink Gram-negative cells
After performing a Gram stain of a mixed culture of Gram-positive and Gram-negative cells, you shout: "Oops, I forgot the iodine step!" What would you expect to see if you observed the slide under the microscope?
What domains have flagella?
All (Bacteria - grow from tip, Archaea - grow from base, Eukarya - wave-like motion)
True
All eukaryotes have a membrane-delimited nucleus.
False (larger)
Although similar in function, the eukaryotic ribosome is generally smaller and more complex than the prokaryotic ribosome.
Lister
Antiseptic surgery was pioneered by
bonds between N-acetyl group sugars?
B-1,4 glycosidic bonds (can be destroyed by lysozyme)
What can break the crosslinked bonds between peptidoglycan layers?
B-lactam (penicillin) - inhibits transpeptidase (crosslinks the peptides)
S-layers can be found in which domains?
Bacteria and Archaea
pleomorphic
Bacterial cells that are variable in shape are called
Carboxysomes
CO2 fixing bacteria contain Rubisco for CO2 fixation (cyanobacteria)
False
Cell walls of most Archaea and Bacteria contain peptidoglycan.
Prokaryotes
Cells with a relatively simple cell morphology that do not have a true membrane-delimited nucleus are called
Production of breads, cheeses, antibiotics, vitamins, enzymes used for many different industrial applications
Check all of the following that showcases how microbes can be used by people.
example organism for Algae
Chlamydomonas reinhardtii - two flagella (good for studying)
True
Chloroplasts are the site for both the light and dark reactions of photosynthesis.
False
Edward Jenner's work in preventing rabies led to the use of the term vaccination to describe a type of procedure used in the prevention of disease.
rough, smooth
Endoplasmic reticulum (ER) with many ribosomes attached is called __________ ER, whereas endoplasmic reticulum that is mostly devoid of ribosomes is called __________ ER.
False
Endospores are reproductive structures.
dipicolinic acid
Endospores are resistant to most environmental stressors because they have _____ complexed with calcium ions which stabilize DNA.
lysosomes
Enzymes needed to digest all types of macromolecules are found in
What domains have cilia?
Eukarya ONLY
hami
External structures that are found in Archaea but not Bacteria are _________.
What type of microscope allows you to see MOLECULES?
Fluorescence
What type of Eukaryotic organism is penicillin made from?
Fungi (Penicillium notatum)
oncogenes
Genes whose expression (or abnormal expression) causes cancer are called
example organism for Protists
Giardia lambia - lacks mitochondria (has mitosome), causes disease, two nuclei, genetically "old"
Specialized cell-surface proteins and slimy polysaccharides
Gliding motility in bacteria involves which of the following?
False
Gram-positive bacteria have a structurally and chemically more complex cell wall than gram-negative bacteria.
False
Gram-positive bacteria have a thinner layer of peptidoglycan than gram-negative bacteria.
False
Gram-positive bacteria have flagella with four basal body rings, while those of Gram-negative bacteria have only two.
Organelles
Membrane delimited intracellular structures that perform specific functions in cells are called
False
Microbiologists study a variety of organisms, but all are considered either Bacteria or Archaea.
hydrophilic
Molecules or regions of molecules that readily interact with water are said to be __________, whereas molecules or regions of molecules that are insoluble in water or do not readily interact with water are said to be hydrophobic.
plasma
Most enveloped viruses use the host __________ membrane as their envelope source.
Koch and ________________? Organism grows very slowly, is hard to stain due to lipid content in cell wall
Mycobacterium tuberculosis
True
Mycoplasma pneumoniae lacks a cell wall and are pleomorphic in shape.
What is the most IMPORTANT macromolecule?
Nucleic Acids
What is the use of moderate heat to reduce number of microorganisms in foods (milk, wine, etc.)?
Pasteurization
Most archaeal cells have a cell wall, but it is not composed of peptidoglycan.
Penicillin inhibits bacterial growth by preventing the cross-linking during peptidoglycan synthesis. Why does penicillin not inhibit growth of archaeal cells?
Two structures that can be used for attachment in Bacteria?
Pili and Fimbraie
domestic animals and humans.
Prions are of significance because they cause infections of
What is the most ABUNDANT macromolecule?
Proteins
both catalysts and structural elements.
Proteins function in modern cells as
example organism for Fungi
Saccharomyces cerevisiae - production of bread, beer, wine via fermentation
What type of microscope allows you to see SURFACE CELL STRUCTURES?
Scanning Electron
invasion of host cells
Select a harmful effect that can result from bacterial colonization of the human body.
True
Spirochetes move in a screw-like manner that is mediated by bundles of flagella located in the cell's periplasmic space.
True
Spore formation is initiated when there is a scarcity of nutrients.
True
Sterol-like molecules called hopanoids are thought to be important for the structural integrity of many bacteria because of their suspected role in membrane stabilization.
A complex peptidoglycan network, Outer membrane, Lipopolysaccharide
The Archaea generally lack which of the following that are normally found in gram-negative bacteria?
packaging of materials for excretion.
The Golgi apparatus is responsible for the
by rotation that is powered by the proton motive force
The bacterial flagellum moves ______.
run
The bacterium E. coli swims in a straight line, called a __________, for a few seconds; then it stops, tumbles, then swims away in a new direction.
plasma membrane, peptidoglycan, outer membrane, periplasmic space
The cell wall of Gram-negative bacterial cells is external to the _____________. This structure contains only a thin layer of _____________. In addition, there is an ___________________ external to the Gram-negative bacterial peptidoglycan layer. The two layer cell wall of Gram-negative bacteria is separated from the plasma membrane by the _________________.
Spontaneous generation
The concept that living organisms arise from nonliving material is called
either DNA or RNA
The nucleic acids carried by viruses usually consist of
peptidoglycan
The plasma membrane of eukaryotes contains all of the following EXCEPT phosphoglycerides peptidoglycan sphingolipids sterols
proton motive force (PMF)
The power used by most bacterial flagellar motors is produced by
crystal violet, iodine, ethanol, safranin.
The proper sequence of reagents in the Gram stain procedure is
RNA or DNA in a protein coat
The simplest viruses consist of
Cortex
The spore layer containing peptidoglycan is the ______.
vibrio
The term used to describe bacteria that are shaped like curved rods is
Eukarya
The three domain system, comprising the bacteria, the _________, and the archaea, was devised in the 1970s by Carl Woese.
What type of microscope allows you to see VIRUSES/PROTEINS/NUCLEIC ACIDS?
Transmission Electron
Type IV pili
Twitching motility involves
plants
Viroids are of economic significance because they cause disease in
Organisms that can't be grown in a lab are?
Viruses (HIV), Treponema pallidum
False
Viruses and bacteria were first cultured in the laboratory at about the same time.
False
Viruses are not generally studied by microbiologists because they are not classified as living organisms.
False
Viruses constitute the fourth domain of life in current biological classification schemes.
False
Viruses have typical cellular structure like other living organisms.
DNA molecules are more chemically stable than RNA molecules.
What is the most compelling reason why DNA, rather than RNA, evolved to be the storage repository for genetic information in cellular life forms?
Scanning electron
What microscope would be the best to use to view cell surface features of a specimen?
Transmission electron microscopy
What would be the best technique to prepare and view the internal structures of fungal hyphae?
Fungi
Which group of microbes contains organisms necessary for production of wine and bread?
Satellite Viruses
Which of the following encodes its own capsid proteins?
Algae (cellulose), Fungi (chitin)
Which of the following eukaryotes typically have cell walls?
Koch's postulates
Which of the following experiments is used to identify new pathogens?
Fluorescence microscope
Which of the following microscopes typically uses dyes or antibodies?
Pili
Which of the following structures are external to both Bacterial and Archaeal cells?
Capsule
Which of the following structures is NOT found in an endospore?
The filament extends out of the cell.
Which statement about flagellar structure is TRUE?
Virulent phage
Which type of phage always lyses its host cell?
Budding
Which virion release process is most often used by enveloped viruses?
Koch
Who of the following developed a set of criteria that could be used to establish a causative link between a particular microorganism and a particular disease?
Pasteur
Who of the following provided the evidence needed to discredit the concept of spontaneous generation?
Group translocation
You discover a new transport system used by a newly discovered bacterial species. The sugars that are transported using this system are phosphorylated as they enter the bacterial cell. You would describe this transport system as a(n) _____.
Ribosomes
_______ are the site of protein synthesis in the cell.
Sporulation
__________ is the process through which endospores are formed within a vegetative cell.
Cannulae, hami
__________________ are hollow tube-like structures that hold some archaeal daughter cells together after cell division while____________ are grappling hook-like structures that appear to attach archaeal cells to surfaces.
Why are proteins bonded to DNA?
adding proteins compacts DNA to take up a very small amount of space in a cell (allows it to fit)
Cytoskeleton
assists in cell division (FtsZ and MreB)
condenser lens
between light source and specimen
Poly-B-hydroxybutyrate (PHB)
carbon/energy source
Glycogen
carbon/energy source, polymer of glucose
objective lens
closest to specimen, 10x 40x or 100x
ocular lens
closest to the eye, typically magnify 10x
What are some downsides to forming a biofilm?
competing for nutrients, infections (viral), accumulate of waste products
S-layer
crystalline array of interlocking proteins, act as armor against predation or infection
Vibrio
curved rod
Taxis
directed movement in response to chemical or physical signals
Alexander Fleming 1929
discovered antimicrobial effects of penicillin (FIRST ANTIBIOTIC) on Staphylococcus
Louis Pasteur
disproved theory of spontaneous generation using the swan necked flask
Archaea
ether linkages
Fimbraie
filamentous protein structures, allow attachment
repellants
flagella fly apart, "tumble", clockwise rotation
Edward Jenner 1778
found that milkmaids exposed to cowpox were immune to smallpox... vaccinated people with cowpox (including his son) and they became resistant to smallpox FIRST VACCINATION
Joseph Lister 1864
found that survival rates of patients increased if surgeons wash hands, sterilize instruments and use disinfectants (carbolic acid/phenol) during surgery - Listerine
Symport
function as co-transporters
Gas vacuoles
gas-filled structures made of protein, buoyancy in photosynthetic microbes, impermeable to water
Two ways to increase resolution?
immersion oil and increase contrast
Where is the only place a virus can reproduce?
inside the host cell
What is one beneficial biofilm in humans?
intestinal tract - breaks down food
ABC (ATP-Binding Cassette) Systems
involved in uptake of organic compounds, inorganic nutrients, and trace metals, contain periplasmic binding proteins, have high substrate specificity
Mycoplasmas
lack cell wall, very small, easier to be pathogenic because our bodies recognize Bacteria from outer cell wall
Peptidoglycan
main component in bacterial cell walls, provides strength, polysaccharide composed of N-acetylglucosamine and N-acetylmuramic acid
Koch's postulates provided scientific basis for determining that a specific ___________ causes a specific ___________.
microbe, disease
peritrichous
more than 2 flagella extending from multiple sides of Bacteria
lophotrichous
more than 2 flagella on one end of Bacteria
Spirochetes
move by axial fibrils
False
obert Koch developed a vaccine that could be used to prevent anthrax.
Robert Hooke
observes small eukaryotic organisms with a microscope (1st to describe molds)
monotrichous
one flagella
Under what condition would you expect a capsule to form?
optimal
What type of microscope allows you to see INTERNAL STRUCTURES/ORGANELLES?
phase contrast (no staining)
Capsules
polysaccharides and proteins, allow adhesion, defense against host immunity (phagocytosis), desiccation, formation of biofilm
Antoni van Leeuwenhoek
published first drawings of bacteria (cocci, spiralli, bacilli)
Mot Protein
pumps H+ ions across the membrane creating a gradient to rotate flagella (more = faster rotation)
attractants
push cell forward, "run", counterclockwise rotation
Sulfur globules
some Gram - can store sulfur globules in the periplasm
Paul Ehrlich 1900s
speculated about a "magic bullet" that could destroy a pathogen without hurting the host... CHEMOTHERAPY
Pasteur disproved _____________ ____________.
spontaneous generation
Group Translocation
substance transported is chemically modified during transport across the membrane, 5 protein transport system that results in phosphorylation of glucose
Pasteurs experiment used the "________-_______" flask.
swan-necked
What is the main purpose of an endospore?
to protect DNA
Antiport
transport a molecule across the membrane while simultaneously transporting another molecule in the opposite direction
Uniport
transport in one direction across the membrane
amphitrichous
two flagella, one on each end of Bacteria
Secondary Active Transport
use ion gradients to co-transport substances uniport symport antiport
Percentage of deaths caused by TB?
~1/7
