Micro Module 1
Select the levels of protein structure that would be disrupted by heat or solvent changes that would disrupt hydrogen bonding.
Heat and solvent changes can disrupt hydrogen bonds. Hydrogen bonds are involved in maintaining secondary, tertiary and quaternary structure of proteins. Primary structure is maintained by peptide bonds that would not be disrupted by heat or solvent changes.
True or False: Bacteria are only visible with an electron microscope.
False -Bacteria are visible with the light microscope.
Choose the description that best fits a medium that has been designed to support the growth of MRSA (methicillin-resistant Staphylococcus aureus) while inhibiting all species and strains of other bacteria
Selective A medium that supports the growth of one type of bacterium while inhibiting the growth of others is a selective medium.
Drag the images to their corresponding class to test your understanding of various types of microbiological stains.
Simple stains involve the use of one dye. Differential staining methods use two different dyes to distinguish between two cell types or parts. Special stains are used to enhance viewing of important structures such as capsules and flagella.
Select the individual below that ground glass lenses to very fine specifications so that he was able to develop a microscope for observing and describing living microscopic animalcules. - Antonie van Leeuwenhoek - Louis Pasteur - Robert Meischer - Gregor Mendel
Antonie van Leeuwenhoek - Antonie van Leeuwenhoek developed the first glass lenses, taking the initial step into the field of microscopy.
When ethanol is applied correctly, gram-positive cells appear ____ and gram-negative cells appear _____. -purple; pink/red -pink/red; purple -colorless; purple -purple; colorless
-purple; colorless Only gram-negative cells lose their purple color after ethanol is used as a decolorizer.
Which of the following DNA molecules is the most stable?
5'-GCGTGCAC-3'3'-CGCACGTG-5'
Label the missing categories in the chart to assess your knowledge of media classification.
Media is classified by its physical state, its chemical composition, and its functional type. Some media can serve more than one function.
Why must fresh cells be used when performing a Gram stain? -Old cells may not Gram stain properly -As cells age, they won't stick to the slide -Fresh cells do not smell as badly as older cells -Fresh cells won't heat-fix proper
Old cells may not Gram stain properly
Match the step of the microbial culturing process to its appropriate description.
The first step in the process of culturing microorganisms from a specimen is to inoculate a variety of media, which usually involves transferring the specimen to culture media and spreading it out. After inoculation, the culture is incubated by placing it in an incubator at the proper growth temperature for a period of time, often 18 - 48 hours. After incubation, microbes are isolated from the initial culture by transferring discrete colonies to fresh media using the quadrant streak method to obtain pure cultures. Inspection involves examining the cultures both macroscopically and microscopically, most likely using a Gram stain. Identification often involves doing a number of different biochemical tests to characterize the microbe and determine the genus and species.
Select the main groups of macromolecules found in living things.
The four main groups of macromolecules in living things are carbohydrates, lipids, proteins, and nucleic acids. While oxygen and carbon dioxide are important molecules in living things, they are not considered macromolecules.
Select characteristics exhibited by viruses.
Viruses are considered to be infectious particles that are simpler than cells and contain DNA or RNA but never both.
Rod-shaped bacteria
can be either gram-positive or gram-negative. Rod-shaped bacteria can be gram-positive, gram-negative, or acid-fast.
The major groups of microorganisms studied by microbiologists include bacteria and archaea, algae, helminths,protozoans, viruses, and _______.
fungi - Fungi are included in the major groups of microorganisms studied by microbiologists.
The correct structure of DNA components can be presented as
phosphate-sugar-base
Structure of Proteins
the amino acid sequence of the polypeptide chain
Select the nitrogen bases found in nucleotides that make up DNA.
DNA nucleotides contain guanine, thymine, adenine, and cytosine. They do not contain uracil.
The differential stage of the Gram stain is the application of _____. -crystal violet -ethanol -iodine -safranin
ethanol Ethanol is the first step in the staining process that shows differences between the two types of bacteria. After its application, the gram-positive bacteria will be purple and the gram-negative bacteria will be colorless.
The term used to describe a cluster of spherical bacteria is _______. -vibrio -staphylococci -streptobacilli -streptococci
staphylococci
Match the macromolecules to their function within cells.
Cell walls typically contain carbohydrates such as cellulose, peptidoglycan, or chitin. Lipids, more specifically phospholipids, are a major component of cell membranes. Many proteins in cells are enzymes which facilitate or catalyze chemical reactions. Nucleic acids (DNA and RNA) encode genetic traits and provide for inheritance.
Nitrogen Bases
Adenine, Thymine, Guanine, Cytosine
True or False: The thinner peptidoglycan layer of gram-positive bacteria allows the crystal-violet-iodine complex to leave the cell.
False Gram-positive bacteria have a thicker peptidoglycan layer that traps the crystal-violet-iodine complex inside the cel
True or False: All bacteria can be classified as either gram-positive or gram-negative.
False Some bacteria are classified as acid-fast, and others lack cell walls completely.
The major groups of microorganisms studied by microbiologists include bacteria and archaea, algae, helminths,protozoans, viruses and ____________.
Fungi are to be included in the major groups of microorganisms studied by microbiologists.
Label the image to assess your knowledge of phospholipid structure.
Phospholipids contain a phosphate head connected to a glycerol group and two fatty acid chains. Review figure 2.19 to help you understand the structure of these important molecules found in cell membranes.
Review important historical foundations of microbiology by completing each sentence. Then, arrange the sentences in chronological order.
The 1800s were the Golden Age of Microbiology, and the 2000s are referred to as the Century of Biology. Both time periods have seen significant discoveries that have impacted the field of microbiology.
Drag the descriptions to their corresponding class to assess your understanding of the three domains of life.
The 3 domains include the following: Eukarya--all organisms represented by cells with a nucleus Bacteria--single-celled organisms without a nucleus Archaea--single-celled organisms without a nucleus that live in extreme environments and are more genetically related to Eukarya than Bacteria
Drag the images and/or statements to their corresponding class to test your understanding of the main types of microbes.
The main types of microbes include helminths (worms), protists (single-celled eukaryotes), fungi (molds and yeast), bacteria, and archaea. Viruses are not considered living organisms, but these particles are also studied in the field of microbiology.
Select all areas that comprise the main concerns of the science of taxonomy.
The primary concerns of modern taxonomy are still naming, classifying, and identifying. These three areas are interrelated and play a vital role in keeping a dynamic inventory of all organisms whether living or extinct.
Select the components necessary for a simple microscope.
Early microscopes consisted of a single magnifying lens, a part to hold the specimen, and few other working parts. They did not have a lamp but instead were illuminated by reflected light.
Label the image to test your understanding of common measurements encountered in microbiology and the size range of microorganisms.
Eukaryotic organisms are larger than most bacteria, archaea, and viruses. Some are large enough to view with the naked eye. Bacteria are larger than viruses. Bacteria are usually measured in micrometers, whereas viruses are usually measured in nanometers.
Select statements that apply to the theory of evolution to test your understanding of evolution.
Evolution is the accumulation of changes that occur in organisms as they adapt to their environments and is an observable phenomenon testable by science. By the time a scientific principle has been labeled a theory, it has undergone years and years of testing and not been disproven.
True or False: The presence of flagella can be determined by a Gram stain.
False Special stains are needed to visualize flagella.
Label this figure to test your knowledge of the general laboratory techniques carried out by microbiologists, also known as the "Five I's of Microbiology."
Inoculation involves introducing samples into the proper medium for growth, such as agar plates, blood, or embryos. Incubators can create the correct temperature (and even atmospheric) conditions for optimal growth of the organism. Isolation involves separating out one type of microbe from another through methods such as streak plating and/or subculturing. Inspection can be done macroscopically or microscopically. Identification can involve biochemical, immunological, and genetic analyses for determination of the actual microbial species.
A human squamous cell measure 75 µm in diameter. Select the measurement that represents the size of this cell in millimeters (mm).
0.075 mm One millimeter is equal to 1000 micrometers. To convert micrometers to millimeters, divide the 75 µm by 1000 to obtain 0.075 mm.
Choose the term(s) identifying professions that involve the use of microorganisms.
Astrology - Microbiologists can work in numerous fields utilizing microbes to study genetics, biochemistry, toxin production, and the relationship of microorganisms with other organisms. Microbes also play a role in the earth's crust, ocean, and maybe even in space. Astrology is the study of how movements and patterns in space can impact human life (horoscopes, etc).
Label the image to review the components of a compound light microscope.
Different brands of light microscopes are slightly different but they usually contain the same basic components of a compound light microscope---ocular lenses in eyepieces, an arm, a revolving nosepiece with several objectives, a stage with some adjustment knobs to move the slide around on the stage, a condenser and iris diaphragm under the stage, two focus knobs, and a light source on the base.
What general type of stain is used to separate types of bacteria based on their cellular structures? -Simple -Acidic -Differential -Negative
Differential -Differential staining techniques can be used to identify different types of bacteria, based on structures like their cell wall or the presence of endospores.
Choose the differential stain that is most important in the diagnosis of tuberculosis.
The acid-fast stain is a differential stain that is useful in the diagnosis of tuberculosis. Tuberculosis is caused by the acid-fast bacterium, Mycobacterium tuberculosis.
Which of the following choices is a correct way to denote the binomial name of a microorganism?
The binomial, or scientific name, of a microorganism must be typed in italics or underlined if handwritten. In addition, the first letter of the generic part of the name must be capitalized while the first letter of the species name is lowercase.
Match the staining technique to the appropriate example.
The methylene blue stain is an example of a simple stain since it uses only one dye. The Gram stain is a differential stain which permits the viewer to distinguish between gram-positive and gram-negative bacteria. The flagellar stain is considered to be a special stain
Move the terms into the correct empty boxes to complete the concept map.
The production of a quality magnified image depends upon three factors: contrast, resolution and magnification. Resolution, or resolving power, is a function of the wavelength of light forming the image and the numerical aperture of the objective lens used. Contrast is increased by adding colored dyes to the specimen for viewing.
Move the terms into the correct empty boxes to complete the concept map.
There are both cellular and non-cellular types of microbes. All non-cellular microbes, such as viruses or prions, lack a nucleus. However, of all the cellular microorganisms, only bacteria and archaea lack a nucleus.
Alpha helices and beta pleated sheets are examples of this level of protein structure:
There are four levels of protein structure. Alpha helices and beta pleated sheets are two different forms of secondary structure, which form due to hydrogen bonding between functional groups on the protein surface.
After Gram's iodine is added, what color do the cells appear under a light microscope? -Some cells may be purple and some may be pink/red -All cells appear pink/red -All cells appear colorless -All cells appear purple
All cells appear purple
Select characteristics exhibited by most bacteria and archaea to test your understanding of the differences between these microorganisms and eukaryotic organisms.
- Nucleus - Golgi Body Bacteria and archaea are less complex in cell structure than eukaryotic cells. They possess a cell wall comprised of peptidoglycan or other unique molecules, a cell membrane, cytoplasm, ribosomes, and DNA (in the form of a chromosome/nucleoid/plasmid). Some species also have a flagellum for motility. Eukaryotic cells may possess any of these structures (cell walls with a different biochemical composition), and in addition, they exhibit a nucleus and other membrane-bound organelles within the cytoplasm.
Match the terms related to recent advances in microbiology with their proper descriptions.
- Restriction enzymes, or "molecular scissors" for cutting DNA were discovered in the 1970s. - In the 1980s, Kary Mullis developed the PCR technique to amplify DNA fragment -Biofilms have been studied over the past 30 years, and they have recently been linked to disease development in humans - Small RNAs were discovered in the 2000s, and play a role in gene regulation in cells. - In 2008, the Human Microbiome project began, with findings released in 2012. - The microbiome refers to all of the microorganisms that call our bodies home.
True or False: Bacteria are larger than human cells.
Fasle -Bacteria are much smaller than eukaryotic cells.
Match the carbohydrate class with the appropriate example of a carbohydrate in that class.
Fructose is a single sugar, or monosaccharide. Lactose is a disaccharide composed of glucose and galactose joined by a glycosidic bond. Cellulose is a polysaccharide.
Label the image to test your understanding of the current taxonomic system that first separates organisms into one of three domains.
Robert Whittaker developed a five kingdom classification system that was the standard for a long time. After newer genetic techniques were developed, a clearer picture of evolutionary relatedness has emerged, and a new standard classification scheme was developed with three domains separating organisms by their cell type.
Asymmetrical spacing of the backbones of the DNA double helix generates major and minor grooves.
True
Doubled-stranded DNA consists of two antiparallel strands, meaning that one strand is oriented in the 5' to 3' direction while the other is oriented in the 3' to 5' direction.
True
Drag the images to their corresponding class to test your understanding of isolation methods.
Streak plating involves diluting one inoculum across the surface of a plate using a quadrant pattern. The growth will be thicker in the first quadrant, but isolated colonies should grow in quadrant three or four. Spread plating involves adding a sample to the surface of a plate and then using a L-shaped glass rod to evenly spread across the surface. Pour plating involves adding a sample to liquefied agar, and then pouring the agar into a plate to solidify. Bacteria will grow in and on the surface of pour plates.
Place the correct category next to each taxonomic level presented for humans.
A common mnemonic device that can be used to remember these levels in order is "King Philip Came Over For Great Spaghetti." With the addition of domains as the highest level of taxonomy, you can add the word "Dear" to the front of this sentence and it still works!
If the Gram's iodine step was skipped in Gram stain procedure, what color would the cells likely be when viewed under the microscope? -Most cells appear purple -Most cells would appear red/pink -Most cells would appear blue -All cells appear colorless
Most cells would appear red/pink The iodine forms a complex with the purple dye molecules, helping it stick in the thick gram-positive cell wall. Without it, the alcohol would most likely wash the crystal violet from all cells and they would stain pink/red in the last step.
Drag the images or descriptions to their corresponding class to test your understanding of the cellular organization and relative size of bacteria, eukaryotes, and viruses.
Viruses are nonliving particles and usually are only nanometers in size so they require an electron microscope for viewing. Bacteria are larger than viruses, falling into the micrometer range. They are cells without a nucleus. Eukaryotes have a nucleus and are larger than both viruses and bacteria. An example is the helminths.
The scientific method is used by scientists to explain a certain natural phenomenon, and it involves the formation of a______ as a tentative explanation of the observed or measured phenomenon.
hypothesis Science is a process of investigation, using observation, experimentation, and reasoning. The scientific method is a process for investigating events or phenomena around us and the investigation starts with the formulation of a hypothesis or a supposition of why the event occurred.
