BIO 175 Exam #1
List some recent microbiology discoveries of great impact.
-1953: the structure of DNA is determined (Watson, Crick, Franklin, and Wilkins) -1954: polio vaccine is developed (Salk) -1979: genetic engineering of insulin -1983: intro of PCR (polymerase chain reaction) (Kerry Mullis) -1997: first cloned mammal is developed (Dolly) -2000: rough version of human genome is mapped -2006: first "cancer" vaccine developed -discovery of restriction enzymes (1970s) -the invention of the PCR technique (1980s) -the importance of small RNAs (2000s) -genetic identification of the human microbiome (2010s-to present)
Differentiate between Bergey's Manual of Systematic Bacteriology and Bergey's Manual of Determinative Bacteriology.
-Bergey's Manual of Systematic Bacteriology: presents a comprehensive view of bacterial and archaea relatedness, based largely on rRNA sequencing information -Bergey's Manual of Determinative Bacteriology: based entirely on phenotypic characteristics, which are the observable characteristics of an organism such as its shape and its metabolic capabilities (such as what it requires to grow); used by microbiologists who need to identify bacteria
List and describe the three main fibers of the cytoskeleton.
-actin filaments: long, thin protein strands, responsible for cellular movements such as contraction, crawling -microtubules: long, hollow tubes that maintain the shape that don't have walls, and transport substance from one part of a cell to another -intermediate filaments: ropelike structures that helps structural reinforcement to the cell and organelles
List the structures all bacteria possess.
-cell membrane -cytoplasm -ribosomes -cytoskeleton -one (or a few) chromosomes
teichoic acid and lipoteichoic acid
-cell wall-associated structures found only in gram positive organisms -teichoic acid plays crucial roles for cell shape, regulation of cell division, and others -lipoteichioc acid adds to the thick peptidoglycan layer
prion
-infectious proteins that do not contain genetic materials like DNA and RNA
Name the four main families of biochemicals.
-macromolecules: large, molecular compounds assembled from smaller subunits, most notably biochemicals -include carbohydrates, lipids, proteins, and nucleic acids -all macromolecules except lipids are formed by polymerization, a process in which repeating subunits termed monomers (a simple molecule that can be linked by chemical bonds to to form larger molecules) are bound into chains of various lengths termed polymers (starch, protein, DNA); for example, proteins (polymers) are composed of a chain of amino acids (monomers)
Describe the protozoan characteristics that illustrate why protozoa are informally placed into a single group.
-most protozoan cells are single cells containing all the major eukaryotic organelles -cytoplasm is divided into two parts, the ectoplasm (the clear outer layer), and the endoplasm (granular inner region) -ectoplasm: involved in locomotion, feeding, and protection -endoplasm: houses the nucleus, mitochondria, and food and contractile vacuoles
Explain how a flagellum works in the presence of an attractant.
-moves in response to chemical signals by chemotaxis -as a flagellum rotates counterclockwise, the cell itself swims in a smooth linear direction toward the stimulus, this actions is called a run and they are interrupted at various intervals by tumble, during which the flagellum reverse direction and causes the cell to stop and change its course
Differentiate between the two main types of bacterial envelope structure.
-moving from outside to in, the outer membrane (if present) lies just under the glycocalyx, next come the cell wall and the innermost layer the cytoplasmic membrane -cell wall: helps determine the shape of a bacterium and it also provides the kind of strong structural support necessary to keep a bacterium from bursting or collapsing because of changes in osmotic pressure; gain their relatively rigid quality from peptidoglycan -gram +: thick and one membrane, no outer membrane (purple) -gram -: with an outer membrane, a cytoplasmic membrane, and a thin cell wall (pink)
pilus
-a hair-like appendage found on the surface of many bacteria and archaea -required for bacterial conjugation (transfer of genetic material by direct cell-to-cell contact) -basically like fimbriae (adhesion, not movement)
viroid
-a plant pathogen consisting of a molecule of naked, circular RNA, lacking the protein coat of a virus
virophage
-a satellite virus that multiplies in the virus factory found in cells co-infected with a larger virus and inhibits replication of its host virus
Compare and contrast selective and differential media, and give an example of each.
-selective media: contains one or more agents that inhibit the growth of certain types of microbes (call them A,B, and C) but not others (D) and thereby encourages, or selects, microbe D and allows it to grow; very important in the initial stages of isolating a specific type of microorganism from samples containing dozens of different species- for example feces, saliva, skin, water, and soil -differential media: do no inhibit the growth of any particular microorganisms but are designed to display visible differences in how they grow; can show up in variations in colony size or color, in media color changes, or in the formation of gas bubbles and precipitates
Koch's Postulates
-series of guidelines used to identify the microorganism that causes a specific disease -the microorganism must be found in abundance in all organism suffering from the disease, but should not be found in healthy organisms -the microorganism must be isolated from a diseased organism and grown in a pure culture -the cultured microorganism should cause disease when introduced into a healthy organism -the microorganism must be preisolated from the inoculated, diseased experimental host and identifies as being identical to the original specific causative agent
Diagram the possible nucleic acid configurations that viruses may possess.
-unlike cells, which contain both DNA and RNA, viruses contain either DNA or RNA but not both
Describe three ways in which viruses are cultivated.
-using live animal inoculation: viruses can exhibit host specificity, certain animals can propagate a give virus more readily than others -using bird embryos: a bird egg containing an embryo provides an intact and self supporting unit, complete with its own sterile environment and nourishment -using cell (tissue) culture techniques: a simple and effective way to grow a population of isolated animal cells in culture; close inspection for signs of infection
retrovirus
-virus that contains RNA as its genetic information -uses an enzyme called reverse transcriptase its RNA to DNA -integrates its viral DNA into the DNA of a host, which allows it to replicate -HIV is an example of a retrovirus
Create a mnemonic device for remembering the taxonomic categories.
Domain- Dorky Kingdom- King Phylum- Philip Class- Crossed Order- Over Family- For Genus- Green Species- Soup
Identify an acellular infectious agent that is studied in microbiology.
-viruses are considered a microorganism however, they are not "living" because they do no consist of cells -they are the smallest of microbes (about 10x smaller than the average bacteria although some of the smallest bacteria are smaller than the largest viruses) -outside their host, they are composed of a small amount of heredity material, either DNA or RNA but never both, wrapped up in a protein covering -consist only of a capsid, nucleic acid, and sometimes an envelope
Distinguish between enveloped and naked viruses.
-viruses possess an additional covering external to the capsid called an envelope, which is usually a modified piece of the host's cell membrane -viruses that consist of only a nucleocapsid are considered naked viruses -both naked and enveloped viruses possess proteins on their outer surfaces that project from either the nucleocapsid or the envelope -the enveloped viruses differ from the naked viruses in the way that they enter and leave a host cell
Discuss the size of viruses relative to other microorganisms.
-viruses represent the smallest infectious agents -more than 2,000 bacterial viruses could fit into an average bacterial cell -more than 50 million polioviruses could be accommodated by an average human cell
Compare and contrast the relative sizes of the different microbes.
-viruses: range from 20nm-450nm -prokaryotic cells (bacteria): range from 250nm-2000nm -eukaryotic cells: range from 2000nm-10,000nm
which of these are acellular microbes?
A. bacteria B. viruses***** C. protozoa D. yeasts
If you study HIV, what sort of microbiologist would you be considered?
A. bacteriologist B. protozoologist C. mycologist D. virologist***
what do you call someone who studies fungal molds?
A. bacteriologist B. protozoologist C. mycologist*** D. virologist
what do you call someone who studies bacteria?
A. bacteriologist*** B. protozoologist C. mycologist D. virologist
The active, feeding and motile stage of the protozoan life cycle is the ______ stage.
A. cyst B. endospore C. trophozoite*** D. merozoite E. all of the choices are correct
from which sources can fungi derive nutrients?
A. dead plants and animals B. living tissues C. rubber D. petroleum products E. all of the choices are correct***
adulthood and mating of helminths occurs in the
A. larvae B. intermediate host C. cyst D. definitive host *** E. egg
which of the following structures are possessed by some, but not all, prokaryotes?
A. ribosomes B. A cell membrane C. one or more chromosomes D. flagella***
Correctly write the binomial name for a microorganism.
Staphylococcus aureus -genus first, species second -genus is capitalized, species is lowercased -italics or underline
life
a distinctive characteristic of a living organism from dead organism, as specifically distinguished by the capacity to grow, metabolize, respond, adapt, and reproduce
List the various types of microorganisms that can colonize humans.
bacteria, archaea, protozoa, fungi, helminths, and viruses
Recall three characteristics common to all cells
carbon, hydrogen, oxygen
satellite viruses
depend on other viruses for replication
trematodes
flatworms and flukes
List the three components of a nucleotide.
nitrogenous base, sugar, phosphate group
List the three components of ATP.
nucleotide with adenine, ribose and three phosphates
nematodes
roundworms
species
-a group of organisms that can reproduce with one another in nature and produce fertile offspring -can also be defined as the most basic category in the system of taxonomy
acid fast stain
-a differential stain used to identify bacteria that are not decolorized by acid-alcohol -identify mycobacteria, which is TB
Name the three nitrogen bases of DNA and RNA.
-adenine always pairs with thymine and cytosine with guanine
Diagram the five-step life cycle of animal viruses.
-adsorption: the virus encounters a susceptible host cell and adsorbs specifically to receptor sites on the cell membrane; the membrane receptors attach proteins that the cell requires for normal function; glycoprotein spikes on the envelope bind to the cell membrane receptors -penetration and uncaring: the entire virus is engulfed (endocytosed) by the cell and enclosed in a vacuole; when enzymes in the vacuole dissolve the envelope and capsid, the virus is uncoated, a process that releases the viral nucleic acid into the cytoplasm -synthesis, Replication and Protein Production: the viral nucleic acid begins to synthesis building blocks for new viruses -assembly: mature virus particles are contracted from the growing pool of parts; the capsid is first laid down as an empty shell that will serve as a receptacle for the nucleic acid strand; one important event leading to he release of enveloped viruses is the insertion of viral spikes into the host's cell membrane so they can be picked up as the virus buds off with its envelope -release: assembled viruses leave their hose in one of two ways; nonenveloped and complex viruses that reach maturation are released when cell ruptures of the enveloped viruses are liberated by budding from the membranes
Give an example of a disease caused by each of the four types of protozoa.
-amoeboid protozoa using pseudopods (sarcodina): acanthamoeba, brain infection -ciliated protozoa (cillophora): balantidium coli (intestinal and other symptoms) -flagellated protozoa (mastigophora): giardiasis (intestinal distress) -apicomplexan protozoa (sporozoa): malaria
provirus
-an inactive viral form that has been intergraded into the genes of the host cell -can also be called prophage
Describe two ways in which fungal spores arise.
-asexual spore formation: product of mitotic division of a single parent cell -sexual spore formation: formed through a process involving the fusion of two parental nuclei followed by meiosis
differences between eukaryote and prokaryote cell membranes
-animal cells have cholesterol -plants have other sterols -bacteria have neither (but gram negative have endotoxin)
Compare and contrast the major features of archaea, bacteria, and eukaryotes.
-archaea and eukaryotes share a number of ribosomal RNA sequences that are not found in bacteria and their protein synthesis and ribosomal subunit structures are similar
Draw a diagram of the three major domains.
-bacteria: the "true" bacteria and blue-green algae includes most pathogenic species -archaea bacteria: extremophiles (grow best in salty or acidic conditions) -eukaryota: the eukaryotic organisms, consisting of animals, plants, fungi, and protists
Identify seven structures that may be contained in bacterial cytoplasm.
-bacterial chromosome: also called a nucleoid that holds DNA in bacteria -plasmids: nonessential pieces of DNA, tiny strands, separate double stranded circles of DNA -ribosomes: the site of protein synthesis -inclusions: store nutrients and respond to periods of low food availability, they can pack gas to provide buoyancy in an aquatic environment -cytoskeleton: contribute to cell shape and cell division -endospores: dormant bodies that have two phases of life, a vegetative cells which is metabolically active and growing, and the endospore which exists initially inside the vegetative cell, but eventually the cell disintegrates and the endospore is on its own
Provide thorough descriptions of both lysogenic and lytic bacteriophage infections.
-bacteriophage: makes bacteria more pathogenic to humans; bacterial host cells were being eaten by some unseen parasite; most contain double-stranded DNA; although the entire phage does not enter the host cell, the nucleic acid penetrated the host after being injected through a rigid rube the phage inserts through the bacterial membrane and wall -lysogenic: the host chromosome carries bacteriophage DNA; viral particles are not produced, the bacterial cells carrying temperate phages do no lyse and appear entirely normal; lysogeny is a less deadly form of parasitism than the full lytic cycle and is thought to be an advancement that allows the virus to spread without killing host -lytic: the host cell becomes so packed with viruses that it lysis-splits open- thereby releasing the mature virions
difference between lytic and lysogenic
-bacteriophages can hijack host cell's machinery for their own replication if surrounding conditions are unfavorable in a process called lytic cycle; killing the host cell, host cell becoming weak and full go viruses and eventually bursts, releasing the new viruses -they may go dormant, know as Lysogenic state, when conditions are favorable; the virus integrates itself into host DNA, when then it is termed prophage where it will replicate
Describe the function and structures of viral capsids.
-capsids: or shell, that surrounds the nucleic acid in the central core -nucleocapsid: together the capsid and the nucleic acid -many animal viruses also possess an additional covering external to the capsid called an envelope
Provide examples of cell components made from each of the families of biochemicals.
-carbohydrates: monosaccharides, disaccharides, polysaccharides -lipids: triglycerides, phospholipids, waxes, and steroids; fats and oils -proteins: enzymes, part of the cell membrane, cell wall, ribosomes -nucleic acids: nucleotides (pentose sugar+phosphate+nitrogen base); adenine (A), guanine (G), cytosine (C), thymine (T), uracil (U)
Describe three major shapes of bacteria.
-cocci (circle) -bacillus (bat): rod shaped -spirllum (squiggles) -vibrio (v)
Explain why a cyst stage may be useful to a protozoan.
-cyst: a large number of species are capable of entering a dormant, resting stage when conditions in the environment become unfavorable for growth and feeding -resistant to heat, drying, and chemicals -can be dispersed by air current -important factor in the spread of disease
Define the cytopathic effect and provide one example.
-cytopathic effect (CPEs): virus-induced damage to the cell that changes its microscopic appearance -one very common CPE is the fusion of multiple damaged host cells into single large cells containing multiple nuclei
Provide brief definitions for defined media and complex media.
-defined media: media whose chemical composition are precisely chemically defined -complex media: media that contains at least one component that is not chemically definable
Summarize the relative burden of human disease caused by microbes.
-despite the benefits of microorganisms, they also contribute pathogens which are agents that causes diseases -infectious disease: any disease caused by a microorganism -we are also witnessing an increase in the number of new (emerging) and older (reemerging) diseases such as AIDS, zika, and TB -10 billion new infections every year -13 million people are affected by infectious disease every year -diseases which were once though to be the result of non-infectious causes, peptic ulcers, cancer, obesity
List two detrimental and two beneficial activities of fungi (from the viewpoint of humans).
-detrimental: infection (health care associated in clinical settings, community acquired with the general population, and opportunistic which infects already weak people) and agriculture (damaging to field plants, rots fresh produce which reduces crop production) -beneficial: decomposing organic matter and returns essential minerals to soil and used in food as yeast for bread and beer
Provide at least four terms to describe bacterial arrangements.
-diplococci: single or in pairs -tetrads: groups of four -staphylococci: irregular clusters (grapes) -streptococci: in chains of a few to hundreds of cells -sarcina: cubical packet of eight, sixteen, or more cells
Explain what it means when viruses are described as filterable.
-early researchers found that when infectious fluids from the victims were passed through porcelain filters designed to trap bacteria, the fluid that came through the filter remained infectious -this result proved that an infection could be caused by a fluid containing agents smaller than bacteria
Diagram how the nucleus, endoplasmic reticulum, and Golgi apparatus act together with vesicles during the transport process.
-endoplasmic reticulum: a series of membrane tunnels used in transport and storage; rough is a continuation of the outer membrane of the nuclear envelope and extends in a continuous network through the cytoplasm, even all the way out to the cell membrane, appears rough because of the large numbers of ribosomes attached to its surface; smooth is a closed tubular network without ribosomes which functions in nutrient processing and in synthesis and storage of nonprotein macromolecules such as lipids -Golgi apparatus: the site in the cell in which proteins are modified and then sent to their final destinations, consists of a stack of several flattened, disc shaped sacs called cisternae; always closely associated with the endoplasmic reticulum; at the site where these two meet buds off tiny membrane-bound packets of protein called transitional that are picked up by the face of the Golgi apparatus; the final actions of this apparatus is to pinch off finished condensing vesicles that will carry the modified proteins to organelles such as lysosomes -lysosome: a vesicle that buds off of the Golgi apparatus, contains a variety of enzymes; involved in digestion of food and in protections against invading microorganism -vacuoles: membrane bound sacs containing fluids or solid particles to be digested, excreted, or stored -segment of DNA code from the nucleus and copied onto RNA and passed through the nuclear pores to the RER; synthesized proteins on the RER are deposited into the lumen and transported into vesicles to the Golgi apparatus; proteins in the Golgi apparatus are chemically modified and packaged into vesicles to be used by the cell
Explain how endosymbiosis contributed to the development of eukaryotic cells.
-endosymbiosis: scientists believe that both bacterial and eukaryotic cells emerged from an earlier, now-extinct, cell type, called the Last Common Ancestor (LCA)
List similarities and differences between eukaryotic and bacterial cytoplasmic membranes.
-eukaryotic cells have a bilayer of phospholipids in which protein molecules are embedded; more stable because of sterols than those of non eukaryotic cells; don't have a cell wall -cytoplasmic membranes of eukaryotes have the same function as those in bacteria and archaea, serving as selectively permeable barriers
Differentiate among the flagellar structures of bacteria, eukaryotes, and archaea.
-eukaryotic microbes move by using flagella or cilia; is 10x thicker, structurally more complex and by an extension of the cell membrane; 9/2 arrangement long sheathed cylinder -prokaryotic has a basil body and move in a propeller type fashion; flagella are for moving to get them to nutrient and away from harm; present in the cytoplasmic membrane using proton gradient for energy
Describe the structure and function of six different structures found on the exterior of a bacterial cell.
-flagella: the capacity of a cell to swim freely through an aqueous habitat; has three distinct parts the filament, the hook, and the basal body -spirochetes: show and unusual, wriggly mode of locomotion caused by two or more long, coiled threads, the axial filaments -pilus: long, tubular structures made of pilin protein produced and used for some type of adhesion -fimbria: short, numerous surface appendage that provide for adhesion but not movement -nanotubes: used as channels for nutrient or energy exchange -s layers: single layers of thousands of copies of a single protein linked together like tiny chain mail, often call the "the armor" of a bacterial cell; only produced when bacteria is in a hostile environment -glycocalyx: developer as a coating of repeating polysaccharide or glycoprotein units, it protects the cell and in some cases helps it adhere to its environment; this is called a capsule when it is bound more tightly to the cell than a slime layer (protects from loss of water and nutrients) and it is denser and thicker, usually visible with a gram negative stain
List the two major groups of helminths, and provide examples representing each body type.
-flatworms: very thin, often segmented body; tapeworms and flukes -roundworms: elongated, cylindrical, unsegmented body
Make a time line of the development of microbiology from the 1600s to today.
-from very early history, humans noticed that when certain foods become spoiled, they became inedible or caused illness and yet other "spoiled" foods did no harm -spontaneous generation: the belief that invisible vital forces present in matter led to the creation of life -this belief was continually reinforced as people observed meat left out in the open soon "produced" maggots -some scientists assumed that microscopic beings were an early stage in the development of more complex ones -abiogenesis: beginning in absence of life -biogenesis: beginning with life
List three general features of fungal anatomy.
-fungus penetrates the substrate and secretes enzymes that reduce it to small molecules that can be absorbed by cells -fungus have enzymes that can digest feathers, hair, wood, rubber -fungus thrive in nutritionally poor or adverse environments and those with high salt or sugar content -spores help the fungus disperse throughout the environment through air, water, and living things
Name four divisions ending in -cutes and describe their characteristics.
-gracilicutes: have gram - cells walls and are thin skinned -firmicutes: have gram + cell walls and are thick skinned -tenericutes: lack a cell wall and are soft -medosicutes: are the archaea, primitive cells with unusual cell walls and nutritional habits
Differentiate among the terms heterotroph, saprobe, and parasite.
-heterotroph: gets nutrients from organic materials; has to eat something that was alive -saprobe: eats substances from dead plants and animals -parasites: lives on or within organism, obtains nutrients and enjoys protection -autotroph: self feeder, converts sunlight to chemical energy to grow; anything that has a chloroplast
Explain the importance of ribosomes, and differentiate between eukaryotic and bacterial types.
-in an eukaryotic cell, ribosomes are larger and form a 80S particle; distributed throughout the cell, some scattered freely in the cytoplasm and cytoskeleton -bacterial cell is 70S
Differentiate among bacteria, archaea, and eukaryotic microorganisms.
-in general, bacterial and archaea cells are about 10 times smaller than eukaryotic cells and they lack many of the eukaryotic cell structures such as organelles -organelles are small, double-membrane-bound structures in the eukaryotic cell that perform specific functions and include the nucleus, mitochondria, and chloroplasts -all bacteria and archaea are microorganisms, but only some eukaryotes are microorganisms -humans are eukaryotes
Summarize the stages of a typical helminth life cycle.
-includes the fertilized egg (embryo), larval, and adult stages -transmitting an infective form, usually an egg or larva, to the body of another host -host in which the larva develops is known as the intermediate host -adulthood and mating occur in a definitive host -sources for human infection include food, soil, and water
List the three principal purposes of cultivating viruses.
-isolate and identify viruses in clinical specimens -prepare viruses for vaccines -do detailed research on voila structure, multiplication cycles, genetics, and effects on host cells
Identify better terms for viruses than alive or dead.
-it is best to describe viruses as either active or inactive
Differentiate between the principles of light microscopy and the principles of electron microscopy.
-light microscopy: uses visible light as a source of illumination -electron microscopy: uses electron beams to form images of specimens, higher magnifications
Name a substance in the envelope structure of some bacteria that can cause severe symptoms in humans.
-lipopolysaccharide (LPS) -also known as endotoxins -are large molecules consisting of a lipid and a polysaccharide, found in the outer membrane of a gram negative cell
Discuss three physical states of media and when each is used.
-liquid media: water-based solutions that do not solidify at temperatures above freezing and flow freely; useful in determining the oxygen requirements of different microbes -semisolid media: contains enough gelatin or agar to thicken but not produce a firm surface; used to determine motility and localize a reaction to a specific site -solid media: provides a firm surface upon which cells can form discrete colonies; used to isolate bacteria and fungi
mycolic acid
-long-chained, branched fatty acids characteristic of members of the genus mycobacterium -the agent that causes TB
List and describe the three elements of good microscopy.
-magnification: the total power of magnification of the final image formed by the combined lenses is a product of the separate power of the two lenses; the enlargement of a specimen through the objective lens then through the ocular lenses -resolution: the capacity of an optical system to distinguish two adjacent objects or points from one another; the factor that most limits the clarity of a microscope's image is its resolving power -contrast: the lack of contrast in cell components can be compensated for by using special lenses and by adding dyes; measure by the degree of bending of light undergoes as it passes from one medium to another
Explain the ways that humans manipulate organisms for their own uses.
-make food products (bread, alcohol, cheeses) -biotechnology: when humans manipulate microorganisms to make products in an industrial setting -genetic engineering: an area of biotechnology that manipulates the genetics of microbes, plants, and animals for the purpose of creating new products and genetically modified organisms (GMOs); synthesis of drugs, hormones, and enzymes -recombinant DNA technology: transfers genetic material from one organism to another and to deliberately alter DNA -bioremediation: the ability of microorganisms-ones already present- to restore stability or to clean up toxic pollutants; can break down chemicals that would be harmful to other organisms
Discuss both persistent and transforming infections.
-persistent infections: although accumulated damage from a virus infection kills most host cells, some cells maintain a carrier relationship, in which the cell harbors the virus and is not immediately lysed; this can last from a few weeks to the remainder of the host's life -transforming infections: some animal viruses enter a host cell and permanently alter its genetic material; the virus carries genes that directly cause the cancer, in other cases the virus produces proteins that induce a loss of growth regulation in the cell leading to dance
Name three noncellular infectious agents besides viruses.
-prions -viroids
the major difference in the composition of cell walls in bacteria and eukaryotes
-prokaryotes usually have peptidoglycan -eukaryotes usually have chitin or cellulose
l forms
-prokaryotic cells that lack a cell wall -can't have cell division because the cell wall is missing so it represents a form of cell division that was important in early forms of life
List the types of eukaryotic microorganisms, and identify which are unicellular and which are multicellular.
-protozoa: always unicellular -fungi algae: may be unicellular or multicellular -helminths: always multicellular
List three means of locomotion exhibited by protozoa.
-pseudopods (false feet) -flagella -cilia
Identify the important features of the scientific method.
-researchers form a hypothesis, then perform experiments or other types of studies that also w them to either accept of reject the hypothesis -after the results are communicated, other scientists reviews and repeat studies in order to verify them or bring them into question -this is a process that distinguishes true research from even the most educated guesses or opinions -this was important for the development of science so that scientists have a set methodology of proving scientific results -before the scientific method, it was difficult to back up scientific claims
Define a species in terms of bacteria.
-species: a collection of bacterial cells, all of which share an overall similar pattern of traits
Give examples of simple, differential, and special stains.
-simple stains: uses a single dye to add color to cells so that they are easier to see -differential stains: uses two differently colored dyes, called the primary dye and the counterstain, to distinguish between cell types or parts; gram stain -special stains: used to emphasize certain cell parts that are not reveled by conventional staining methods; capsular staining is a method of observing the microbial capsule, an unstructured protective layer surrounding the cells of some bacteria and fungi; flagellar staining is a method of revealing flagella, the tiny, slender filaments used by bacteria for locomotion
the major difference between bacteria and eukaryotic flagella
-simpler in bacteria, made of microtubules and membrane in eukaryotes
Discuss the primary reason that antiviral drugs are more difficult to design than antibacterial drugs.
-since viruses "borrow" host proteins and functions to propagate themselves, it is difficult to find drive that will affect the virus without damaging host cells -almost all antiviral drugs have been designed to target one of the steps in the viral life cycle -since antiviral drugs are so much trickier to design than antibacterial, scientist have turned to vaccine development to prevent viral diseases
Explain the importance of viral surface proteins, or spikes.
-spikes: molecules that allow viruses to dock with their host cells -essential for the attachment of viruses to the next host cell
Detail the causes and mechanisms of sporogenesis and germination.
-sporogenesis: starts as the depletion of nutrients; the complete transformation of a vegetative cell into a sporangium and then into an endospore requires 6 to 10 hours; causes are lack of water or food, too much UV light, mutagen (unfavorable living conditions) -germination: the reversal of dormancy when conditions are favorable; causes are the presence of water and a specific germination agent that stimulates the formation of hydrolytic enzymes
cestode
-tapeworm with a head and segmented body parts that is capable of growing to several yards in the human intestine
Differentiate among the terms nomenclature, taxonomy, and classification.
-taxonomy: the formal system for organizing, classifying, and naming living things -nomenclature: the assignment of scientific names to the various taxonomic categories and to individual organisms (naming); the scientific name is always a combination of the genus name followed by the species name, the genus part is capitalized and the species part begins with a lowercase letter, both should be italicized -classification: the orderly arrangement of organisms into a hierarchy -identification: the process fo discovering and recording the traits of organisms so that they may be recognized or names and place in an overall taxonomic scheme
Explain the function of the mitochondrion.
-the bulk of cell's energy is generated -holds enzymes and electron carrier of aerobic respiration -extracts chemical energy contained in nutrient molecules and stores it as ATP
Discuss why gram-positive cell walls are stronger than gram-negative cell walls.
-the bulk of the gram + cell wall is a thick, homogeneous health of peptidoglycan and also contains tightly bound acidic polysaccharides -the gram - cell wall is a single, thin sheer of peptidoglycan , its thinness makes it more susceptible to lysis (rupture)
Explain the relationship between fungal hyphae and the production of a mycelium.
-the colonies of yeasts have a soft, uniform texture and appearance -mycelium: the woven, intertwining of hyphae that makes up the body or colony of a mold
Relate bacterial, archaeal, and eukaryotic cells to the Last Common Ancestor
-the first primitive eukaryotes were probably single-celled and independent but overtime some cells began to aggregate, forming colonies -bacteria, archaea, and eukaryotic cells evolved from a different kind of cell, precursor to both prokaryotes/eukaryotes that biologist call the last common ancestor -ancestor was neither prokaryotic nor eukaryotic, but gave rise to all three types
Identify three structures some but no all bacteria possess.
-the majority have a cell wall and a surface coating called a glycocalyx -flagella -an outer membrane -pili -nanotubes
Describe the main structural components of a nucleus.
-the nucleus is a compact sphere that is the most prominent organelle of eukaryotic cells -it is separated from the cell cytoplasm by an external boundary called a nuclear envelope -the nucleus is filled with a matriculates called the nucleoplasm and a granular mass, the nucleolus, that stains more intensely than the immediate surroundings because of its RNA content -a prominent feature of the nucleoplasm in stained preparations is a network of dark fibers known as chromatin, made of linear DNA, which is the genetic material of the cell
Analyze the relative importance of viruses in human infection and disease.
-the number of viral infections that occur on a worldwide basis is nearly impossible to measure accurately -although most viral infection do not result in death, some, such as rabies, AIDS, and Ebola, have high mortality rates and others can lead to long term consequences like polio
Differentiate among primary, secondary, tertiary, and quaternary levels of protein structure.
-the reason that proteins are so varied and specific is that the way they are filed makes all the difference with respect to their function -primary: the type, number, and order of amino acids in the chain, which varies from protein to protein -secondary: various functional groups exposed on the outer surface of the molecule interact by forming hydrogen bonds -tertiary: additional bonds forming between functional groups in a secondary structure, creating a three dimensional mass -quaternary: most complex protein structure that is the formation of of large, multiunit proteins by more than one of the polypeptides; typical for antibodies
Explain the theory of evolution and why it is called a theory.
-theory of evolution: the evidence that proves how evolution occurs -evolution: the accumulation of changes that occur in organisms as they adapt to their environment -it is called a theory because in science a theory begins as a hypothesis and by the time it is labeled as a theory, it has undergone years and years of testing and not been disproved, it become a fact -the theory of evolution refers to a well-studied and well-stablished natural phenomenon, not just a random guess
Describe the role and impact of microbes on the Earth.
-they reproduce so rapidly and we can quickly grow large populations in the lab, but can't see them directly -shaped the development of the Earth's habitats and the evolution of other life forms -photosynthetic microbes make up to 70% of the oxygen in the atmosphere -microbes underground impact weathering, mineral extraction, and soil formation -produce gases in the atmosphere which are responsible for maintaining the temperature of the Earth -help plants obtain nutrients, water, and protection from disease
Explain the difference between traditional and molecular approaches to taxonomy.
-traditional taxonomy: began with Carl von Linn who used Morphology (shape and structure) to classify and name organisms -molecular approaches: using rRNA sequences to put organisms into domains and using genome sequences to classify organisms that are more alike in their genome compare to their morphology
Convert among the different units of the metric system.
-whereas the dimensions of macroscopic organisms are usually given in centimeters (cm) and meters (m), those of microorganisms fall within the range of millimeters (mm) to micrometer (um) to nanometers (nm) - the very smallest of the microbes are the viruses, ranging from 20 nm to about 400 nm - the smallest bacteria is around 200nm and the largest 750um -fungi are generally 3 to 4 um -protozoa are generally around 3 to 4 mm
Explain what the Five I's are and what each step entails.
1. inoculation: sample is placed into a container of growth medium, medium can be solid or liquid or a live animal such as a chicken embryo 2. incubation: an incubator creates the proper growth conditions with respect to temperature and gas requirements 3. isolation: once the cultures have grown, they may need to be re-inoculated (and incubated) in such a way that separate species are obtained 4. inspection: the colonies on agar or the broth cultures are observed macroscopically and microscopically, possibly with the aid of staining 5. identification: the identity of the isolated microbe is determined, usually to the species level; inspection may be enough to identify some microbes but additional techniques
