Microbiology Final Review
enzymes that speed up a chemical reaction in a cell are usually comprised of _____________
proteins
algae and protozoa are also referred to as ________________
protists
synthesis reaction
reactants are combined to form a product
decomposition reaction
reactants are separated to make multiple products
without microorganisms, substances required for human life such as O2 and organic nitrogen would _____________
run out
molecules that pass freely through a lipid bilayer can move across the cytoplasmic membrane by ________________ diffusion
simple
antiseptics are used to decrease the number of bacteria on __________ to prepare for invasive procedures
skin of the patient
although stocks of the causative agent still exist, humans have eradicated which of the following diseases -aids -smallpox -cholera -bubonic plague
smallpox
in the name escherichia coli K12, the part after the species is the __________ designation
strain
DNA is a double-stranded helical structure; the backbone of each strand is a series of alternating __________ and _________ units
sugar and phosphate
lactose
sugar naturally present in milk
describe the transition step and the tricarboxylic acid cycle
the transition step converts the pyruvate from glycolysis into acetyl-CoA the TCA cycle oxidizes a 2-carbon acetyl group to release two molecules of CO2 together they generate the most reducing power of all the central metabolic pathways
the human microbiome project __________
used DNA sequencing to characterize microbial communities that inhabit the human body
rank the following from highest to lowest magnifying capability -light microscope -atomic force microscope -electron microscope
-atomic force microscope -electron microscope -light microscope
which microorganisms lack a membrane-bound nucleus
-bacteria -archaea
which of the following are found in DNA nucleotides -deoxyribose -thymine -guanine -ribose -uracil -adenine -cytosine
-deoxyribose -thymine -guanine -adenine -cytosine
which of the following are groupings of cells resulting from the division process -grape-like clusters -chains -coccobacilli -diplococci -cubical packets
-grape-like clusters -chains -diplococci -cubical packets
algae are ________
-single-celled, photosynthetic eukaryotes -multicellular, photosynthetic eukaryotes
unlike the term microorganism, the word microbe also includes __________
viruses
which of the following is/are true regarding viruses -viruses can only multiply within host cells -viruses are composed of cells -outside of host cells, viruses are inactive
-viruses can only multiply within host cells -outside of host cells, viruses are inactive
RNA differs from DNA in which ways
RNA has uracil instead of thymine and RNA has the sugar ribose instead of deoxyribose
what enzyme binds to a DNA promoter region to initiate transcription
RNA polymerase
ozone
a strong oxidizing agent
the critical site of an enzyme to which a substrate binds by weak forces is called _________ _________
active site
polyadenylation
adenine derivatives at the 3' end
polypeptides are chains of ________ that have been joined together by peptide bonds
amino acids
when a molecule other than O2 serves as the terminal electron acceptor for the ETC, the organism is utilizing _____________ respiration
anaerobic
is Cl- a cation or anion
anion
as a general rule, proteins from thermophiles _______________
are not denatured at high temperatures
what term is used to describe organisms that use CO2 as a carbon source
autotrophs
which of the following are medically relevant endospore-producing genera -bacillus -mycobacterium -clostridium -escherichia
bacillus clostridium
unlike other organisms, most ___________ have cell walls that contain peptidoglycan
bacteria
which of the following are manufactured by microbial fermentation -beer -ice cream -cheese -yogurt -fresh milk
beer cheese yogurt
using microorganisms to degrade toxic chemical spills is an example of __________
bioremediation
maltose
breakdown product of starch
is Na+ a cation or anion
cation
an outbreak of foot-and-mouth disease in england was controlled by ____________
destroying millions of pig, sheep, and cattle
describe respiration
electrons extracted from glucose are transferred to the ETC the ETC uses the electrons to generate a proton motive force that can be used to generate ATP
what is true regarding forms of energy
energy can be changed from one form to another
a change in the nucleotide sequence of DNA can result in a change in the ____________
folding of a polypeptide amino acid sequence of a protein
an endospore can survive harsh conditions and _________, or exit the dormant stage
germinate
an extreme ____________ specifically requires a high concentration of salt for growth
halophile
bacteria such as staphylococcus that can tolerate high salt concentrations found on human skin are _______________
halotolerant
john tyndall's experiments in the 1800s showed that microorganisms remained in some broths even after boiling for 5 hours. he later realized that the results of his experiment were due to the presence of endospores. pasteur might have had results similar to tyndall's if he had used which materials to make his broths?
hay soil
it is important to minimize the number of pathogens in health-care settings due to the risk of ____________ - associated infections
healthcare
an organism that must consume organic matter is called a(n) ___________________
heterotroph
mesophile
human body
phospholipids have a polar phosphate head that is __________ and a non-polar lipid tails that are ___________
hydrophilic hydrophobic
order of events of transcription
initiation elongation termination
describe a petri dish
it is a two part covered container made of plastic or glass, it excludes airborne contaminants, and a culture medium in a petri dish can be referred to as a plate of that medium
autotrophs use CO2 to synthesize organic compounds; describe the process
it often involves the calvin cycle called carbon fixation in photosynthetic organisms, the process is called the light-independent reactions
___________ phase describes the initial phase after bacterial cells are placed into a new environment and are gearing up for cell division, but their numbers have not yet increased
lag
the outer membrane of a gram-negative cell is a lipid bilayer that contains ______________
lipopolysaccharide
the series of sequential chemical reactions in a cell that converts a starting compound to an end product is called a ____________ pathway
metabolic pathway
cap
methylated guanine derivative at the 5' end
which of the following are characteristics of protozoa -multicellular eukaryotes -microscopic -possess a rigid cell wall -single-celled eukaryotes
microscopic single-celled eukaryotes
modern-day bacterial endosymbionts in eukaryotic cells have similarities to ______________
mitochondria and chloroplasts
a concentrated culture of cells will take ___________ time to kill than a dilute culture of the same organisms
more
compared to a typical prokaryotic cell, a eukaryotic cell is generally much ________
more complex larger
electron
negatively charged particle
what microbes are highly resistant to chemical control methods
non-enveloped viruses bacterial endospores protozoan cysts and oocysts mycobacterium species
organisms that populate the human body and which protect it from disease are termed _______________ _________________
normal microbiota
the class of molecules that encode the genetic information of the cell is called ___________ ______________
nucleic acid
all DNA nucleotides contain the same deoxyribose and phosphate group but different ....
nucleobases
the _______ sequence of DNA encodes the ________ sequence of protein
nucleotide; amino acid
___________ is the diffusion of water across a selectively permeable membrane
osmosis
a __________ is the term used for any disease-causing microorganism
pathogen
the chemical bond between the carbon and nitrogen of two amino acids is specifically referred to as a(n) ___________ bond
peptide
the strength of the bacterial cell wall is due to the layer of _____________
peptidoglycan
an autotrophic organism that uses light for energy and carbon dioxide as a carbon source is termed a _____________
photoautotrophs
a _________ is a circular DNA molecule that is smaller than the chromosome and typically encodes non-essential characteristics that can be advantageous to a cell
plasmid
protron
positively charged particle
in living organisms, carbohydrates play important roles in all of the following EXCEPT -energy source and storage -primary structure of the cell membrane -component of genetic material -carbon source for biosynthesis -structural component of cell walls
primary structure of the cell membrane
psychrotroph
refrigeration
what term is used to describe a group of microbes co-existing in polymer-encased communities
biofilm
microorganisms are useful in the study of higher life forms for which of the following reasons -there are fewer species of microorganisms, so studying them is simpler -microorganisms have the same basic metabolic mechanisms -microorganisms multiply quickly -microorganisms lack cells, making them easier to observe with a microscope -microorganisms are cheaper to study -microorganisms have the same fundamental genetic properties
-microorganisms have the same basic metabolic mechanisms -microorganisms have the same fundamental genetic properties -microorganisms multiply quickly
when viewed using a microscope, the object is magnified by a factor equal to the product of the magnifying powers of the _________ lens and the _________ lens
ocular and objective
why are cells sometimes difficult to see in a wet mount
some are transparent some move quickly
what happens to glucose inside a cell
some glucose might be oxidized to CO2, generating the maximum amount of ATP glucose can be used in catabolism to yield energy, or the precursor metabolites generated from its breakdown can be used in anabolism some glucose might enter glycolysis, only to be siphoned off as a precursor metabolite for biosynthesis
when an extensive amount of experimental evidence supports a hypothesis, the explanation may become a scientific _____________
theory
the first shell of an atom can hold a maximum of ______ electrons
two
neutron
uncharged particle
which of the following pairs conform to the base-pairing rules -G/C -A/G -T/C -A/T
-G/C -A/T
which of the following are molecules but NOT compounds -N2 -O2 -H2O -CH4 -NH3 -H2
-N2 -O2 -H2
order the stages of the growth curve
1. lag phase 2. lor or exponential phase 3. stationary phase 4. death phase 5. phase of prolonged decline
rank the steps in the scientific process in order -communicating the methods, results, and conclusions -develop an explanation and then devise an experiment to test this explanation -make an observation about something and ask a question about the situation -collect data from this experiment and draw a conclusion
1. make an observation about something and ask a question about the situation 2. develop an explanation and then devise an experiment to test this explanation 3. collect data from this experiment and draw a conclusion 4. communicating the methods, results, and conclusions
RNA polymerase synthesizes a strand of RNA in the ________ direction
5' to 3'
because less than 1% of microorganisms can currently be grown in the laboratory, most of what we know about the other 99% comes from _____________
DNA sequencing
what are important electron carriers for a cell
NAD+/NADH FAD/FADH2 NADP+/NADPH
why are cells growing in a colony on solid media likely to be in many more different phases of growth than cells growing in liquid culture
cells in liquid culture experience a relatively uniform environment, so they are much more likely to be in the same phase of growth unlike cells on the edge of a colony, those in the center of a colony face depleted levels of nutrients and O2 yielding different phases of growth
proteins involved in folding newly synthesized proteins into functional structures
chaperones
a _________ bond is a link formed when two atoms share, donate, or accept electrons
chemical
which term describes organisms which acquire their energy from chemical compounds
chemotrophs
sucrose
table sugar from sugar cane and beets
the region of DNA that signals the end of an RNA transcript is the _______ sequence
termination
a regular light microscope has sufficient resolving power to distinguish ___________
the general morphology of a prokaryotic cell
what is true about glycolysis
the pathway splits glucose and oxidizes it to form two molecules of pyruvate the pathway provides the cell with a small amount of ATP, some reducing power, and six precursor metabolites
explain the events leading to plasmolysis
the solute concentration of the medium is greater than that in the cell, causing water to diffuse out of the cell due to osmosis
describe an exergonic reaction
the starting compounds have more free energy than the products the reaction releases energy as it proceeds
in photosynthesis, what do the light reactions, or light-dependent reactions accomplish
they capture radiant energy and convert it to chemical energy in the form of ATP
why were louis pasteur's experiments with swan-necked flasks so important in helping disprove the theory of spontaneous generation
they ended arguments that a "vital force" was necessary for spontaneous generation, while preventing contamination from microbes in the air
certain intermediates of catabolic pathways, called precursor metabolites, are important because
they serve as carbon skeletons from which subunits of macromolecules can be made
what two essential cellular processes directly involve DNA
transcription DNA replication
the process of decoding the information carried by mRNA to synthesize a protein
translation
which of the following is a difference between archaea and bacteria -archaea are generally rod-shaped whereas bacteria are generally round -bacteria are found in extreme environments whereas archaea are not -archaea have a nucleus and bacteria do not -bacteria possess peptidoglycan in their cell walls whereas archaea do not
bacteria possess peptidoglycan in their cell walls whereas archaea do not
psychrophile
cold arctic regions
thermophile
compost heap
pasteur is famous for his experiments that contradict spontaneous generation. consider this set up: after showing that the fluid in the swan-neck flasks remained sterile even when exposed to air, pasteur tipped the flasks so that bacteria could enter the fluid. he demonstrated that nothing in his original set-up prevented bacteria from growing in the flask. what part of the scientific method does this represent
control
a chemical bond that involves the sharing of pairs of electrons between two atoms is a ____________ bond
covalent
a disaccharide is composed of two monosaccharides joined together by which type of bond
covalent
what acts as a selective barrier between the interior and exterior of the cell
cytoplasmic membrane
long protein structures responsible for most types of prokaryotic motility are called ____________
flagella
what is true regarding freezing
freezing is a common method used to preserve stock cultures of bacteria freezing is a good method for preserving foods for long-term storage
what are the effects of increasing the pressure of water in an autoclave
increases the temperature at which steam forms increases the boiling point of water