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Review
1. Which theory challenged the case for spontaneous generation? Rudolf Virchow’s concept of biogenesis, stating that living cells arise only from preexisting ones, challenged the case for spontaneous generation. 2. Briefly state the role microorganisms play in each of the following: a. biological control of pests Certain microorganisms cause diseases in insects. Microorganisms that kill insects can be effective biological control agents because they are specific for the pest and do not persist in the environment. b. recycling of elements Carbon, oxygen, nitrogen, sulfur, and phosphorus are required for all living organisms. Microorganisms convert these elements into forms that are useful for other organisms. Many bacteria decompose material and release carbon dioxide into the atmosphere, which plants use. Some bacteria can take nitrogen from the atmosphere and convert it into a form that plants and other microorganisms can use. c. normal microbiota Normal microbiota are microorganisms that are found in and on the human body. They do not usually cause disease and can be beneficial. d. sewage treatment Organic matter in sewage is decomposed by bacteria into carbon dioxide, nitrates, phosphates, sulfate, and other inorganic compounds in a wastewater treatment plant. e. human insulin production Recombinant DNA techniques have resulted in insertion of the gene for insulin production into bacteria. These bacteria can produce human insulin inexpensively. f. vaccine production
Microorganisms can be used as vaccines. Some microbes can be genetically modified to produce components of vaccines. g. biofilms Biofilms are aggregated bacteria adhering to each other and to a solid surface.
3. Into which field of microbiology would the following scientists best fit? Researcher Who Field a. Studies biodegradation of 1. Biotechnology toxic wastes 2. Immunology b. Studies the causative agent of 3. Microbial ecology Ebola virus disease 4. Microbial genetics c. Studies the production of human 5. Microbial physiology proteins by bacteria 6. Molecular biology d. Studies the symptoms of AIDS 7. Mycology e. Studies the production of toxin 8. Virology by E. coli f. Studies biodegradation of pollutants g. Develops gene therapy for a disease h. Studies the fungus Candida albicans a. 1, 3 b. 8 c. 1, 4, 5 d. 2 e. 5 f. 3 g. 6 h. 7
a. Avery,MacLeod,and McCarty b. Beadle and Tatum c. Berg d. Ehrlich e. Fleming f. Hooke g. Iwanowski h. Jacob and Monod i. Jenner j. Koch k. Lancefield l. Lederberg and Tatum m. Lister n. Pasteur o. Stanley p. van Leeuwenhoek q. Virchow r. Weizmann Column B
- Developed vaccine against smallpox
- Discovered how DNA controls protein synthesis in a cell
- Discovered penicillin
- Discovered that DNA can be transferred from one bacterium to another
- Disproved spontaneous generation
- First to characterize a virus
- First to use disinfectants in surgical procedures
- First to observe bacteria
- First to observe cells in plant material
and name them
- Observed that viruses are filterable material
- Proved that DNA is the hereditary material
- Proved that microorganisms can cause disease
- Said living cells arise from preexisting living cells
- Showed that genes code for enzymes
- Spliced animal DNA to bacterial DNA
- Used bacteria to produce acetone
- Used the first synthetic chemotherapeutic agent
- Proposed a classification system for streptococci based on antigens in their cell walls 5. a. 11 b. 14 c. 15 d. 17 e. 3 f. 9 g. 10 h. 2 i. 1 j. 12 k. 18 l. 4 m. 7 n. 5 o. 6 p. 8 q. 13
Multiple Choice
1. Who proposed the system of scientific nomenclature as early as in 1735? a. Edward Jenner b. Carolus Linnaeus 1. b 2. Which of the following is not a characteristic of algae? a. have cell walls made of chitin (Fungi wall) b. are able to photosynthesize (Algae Tao) c. exhibit both sexual and asexual reproductive forms (Algae Tao) d. inhabit water, soil, and plants (Algae Tao) e. are protists (Algae Tao) 2. a 3. Which of the following is the most important element of Koch’s germ theory of disease? The animal shows disease symptoms when a. the animal has been in contact with a sick animal. b. the animal has a lowered resistance. c. a microorganism is observed in the animal.
d. a microorganism is inoculated into the animal. e. microorganisms can be cultured from the animal.
3. d 4. Recombinant DNA is a. DNA in bacteria. b. the study of how genes work. c. the DNA resulting when genes of two different organisms are mixed. d. the use of bacteria in the production of foods. e. the production of proteins by genes. 4. c 5. Which of the following statements is the best definition of biogenesis? a. Nonliving matter gives rise to living organisms. b. Living cells can only arise from preexisting cells. c. A vital force is necessary for life. d. Air is necessary for living organisms. e. Microorganisms can be generated from nonliving matter. 5. b 6. Which of the following is not a beneficial activity of microorganisms? a. Some microorganisms produce methane and ethanol. b. Some microorganisms recycle nutrients. c. Some microorganisms form biofilms on medical implants. d. Some microorganisms are used in gene therapy. e. Some microorganisms are used in the bioremediation of pollutants. 6. c 7. It has been said that bacteria are essential for the existence of life on Earth. Which of the following is the essential function performed by bacteria? a. control insect populations b. directly provide food for humans c. decompose organic material and recycle elements
4. Find at least three supermarket products made by microorganisms. ( Hint: The label will state the scientific name of the organism or include the word culture , fermented , or brewed .) 5. In the 1960s, many physicians and the public believed that infectious diseases were retreating and would be fully conquered. Discuss why this didn’t happen. Is it possible? Clinical Applications and Evaluation 1. Leptospirosis is a bacterial disease caused by the Leptospira species. Humans contract this disease when they come in contact with the urine or feces of infected animals. The prevalence of this disease is ten times higher in tropical regions than in temperate regions. Leptospirosis outbreaks generally increase during hurricanes, floods, and the rainy season. a. Suggest a suitable treatment for this infectious disease. b. Why is the prevalence of this disease higher in tropical regions, especially during the rainy season? 2. In 1864, Lister observed that patients recovered completely from simple fractures but that compound fractures had “disastrous consequences.” He knew that the application of phenol (carbolic acid) to fields in the town of Carlisle prevented cattle disease. Lister treated compound fractures with phenol, and his patients recovered without complications. How was Lister influenced by Pasteur’s work? Why was Koch’s work still needed? 3. Discuss whether antibacterial soaps and detergents should be used in the home.
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Review Review
- What are isotopes of an element? Isotopes are atoms that have the same number of protons but different number of neutrons.
- DRAW IT Diagram the electronic configuration of a carbon atom.
- What type of bond holds the following atoms together? a. Li+ and Cl- in LiCl a. Ionic b. carbon and oxygen atoms in methanol b. Single covalent bond c. oxygen atoms in O 2 c. Double covalent bonds d. a hydrogen atom of one nucleotide to a nitrogen or oxygen atom of another nucleotide in: d. Hydrogen bond
for bacterial growth normally maintained? The H+ concentration of the broth is 10-6 moles/liter, so its pH is
- log10[10-6] = -(-6) = 6. To maintain the pH of a medium, pH buffers are used.
- Classify the following as subunits of either a carbohydrate, lipid, protein, or nucleic acid. a. CH3¬(CH 2 ) 7 ¬CH=CH¬(CH 2 ) 7 ¬COOH Oleic acid a. Lipid b. b. Protein c. C6H12O c. Carbohydrate d. Thymine nucleotide d. Nucleic acid
- DRAW IT The artificial sweetener aspartame, or NutraSweet®, is made by joining aspartic acid to methylated phenylalanine, as shown below.
a. What types of molecules are aspartic acid and phenylalanine? a. Amino acids b. What direction is the hydrolysis reaction (left to right or right to left)? b. Right to left Hydrolysis is a chemical reaction in which a water molecule is used to break a bond in another molecule. The term comes from the Greek words hydro- meaning "water" and -lysis meaning "to break apart." During hydrolysis, a water molecule is added, and it typically splits a large molecule into two smaller molecules. c. What direction is the dehydration synthesis reaction? c. Left to right d. Circle the atoms involved in the formation of water. e. Identify the peptide bond.
- DRAW IT The following diagram shows the bacteriorhodopsin protein. Indicate the regions of primary, secondary, and tertiary structure. Does this protein have quaternary structure?
b. lipids. c. proteins. d. water. e. none of the above
1. c
- If Pseudomonas bacteria are supplied with radioactively labeled cytosine, after a 24-hour incubation period this cytosine would most likely be found in the cells’ a. carbohydrates. b. DNA. c. lipids. d. water. e. proteins. 2. b
- If E. coli were grown in a medium containing the radioactive isotope 32 P, the 32 P would be found in all of the following molecules of the cell except a. ATP. (Adenosine Triphosphate) b. carbohydrates. c. DNA. (nucleotic) d. plasma membrane. (phosphor lipids) e. none of the above
- b
- The optimum pH of Acidithiobacillus bacteria (pH 3,) is times more acid than blood (pH 7). a. 4 b. 10 c. 100 d. 1000 e. 10,
- e
- The best definition of ATP is that it is a. a molecule stored for food use. b. a molecule that supplies energy to do work.
c. a molecule stored for an energy reserve. d. a molecule used as a source of phosphate.
5. b
- Which of the following is an organic molecule? a. H 2 O (water) b. O 2 (oxygen) c. C 18 H 29 SO 3 (Styrofoam) d. FeO (iron oxide) e. F 2 C=CF 2 (Teflon) 6c. C 18 H 29 SO 3 (Styrofoam) Classify each of the molecules on the left as an acid, base, or salt. The dissociation products of the molecules are shown to help you.
- HNO 3 H
7a. acid
- H 2 SO 4 2H
- NaOH Na
9b. base
- MgSO 4 Mg 2+
- SO 4 2- 10c. salt a. acid b. base c. salt Analysis
- When you blow bubbles into a glass of water, the following reactions take place: H 2 O + CO 2 A H 2 CO 3 B H + + HCO 3 - a. What type of reaction is A? synthesis, b. What does reaction B tell you about the type of molecule H2CO3 is? acid
- What are the common structural characteristics of ATP and DNA
T-A (1 pair) = 2 hydrogen bonds Total hydrogen bonds to break: A-T pairs: 2 bonds × 2 = 4 bonds G-C pairs: 3 bonds × 6 = 18 bonds Total : 4 + 18 = 22 hydrogen bonds need to be broken to unwind this stretch of DNA. Now, for the sequence 3' ATAAATTCC 5' , its complementary strand would be: TATTTAAGG 3'. Breaking it down: A-T (1 pair) = 2 hydrogen bonds T-A (1 pair) = 2 hydrogen bonds A-T (1 pair) = 2 hydrogen bonds A-T (1 pair) = 2 hydrogen bonds T-A (1 pair) = 2 hydrogen bonds T-A (1 pair) = 2 hydrogen bonds A-T (1 pair) = 2 hydrogen bonds T-A (1 pair) = 2 hydrogen bonds A-T (1 pair) = 2 hydrogen bonds Total hydrogen bonds to break: A-T pairs: 2 bonds × 9 = 18 bonds Total : 18 hydrogen bonds need to be broken to unwind this stretch of DNA. Clinical Applications and Evaluation
- Ralstonia bacteria make poly-b-hydroxybutyrate (PHB), which is used to make a biodegradable plastic. PHB consists of many of the monomers shown below. What type of molecule is PHB? What is the most likely reason a cell would store this molecule?
- Acidithiobacillus ferrooxidans was responsible for destroying buildings in the Midwest by causing changes in the earth. The original rock, which contained lime (CaCO 3 ) and pyrite (FeS 2 ), expanded as bacterial metabolism caused gypsum (CaSO 4 ) crystals to form. How did A. ferrooxidans bring about the change from lime to gypsum?
- Newborn babies are tested for phenylketonuria (PKU), an inherited disease. Individuals with this disease are missing an enzyme to convert phenylalanine (phe) to tyrosine; the resulting accumulation of phe can cause mental retardation, brain damage, and seizures. The Guthrie test for PKU involves culturing Bacillus subtilis , which requires phe to grow. The bacteria are grown on media with a drop of the baby’s blood. a. What type of chemical is phenylalanine? b. What does “no growth” in the Guthrie test mean? c. Why must individuals with PKU avoid the sweetener aspartame?
- The antibiotic amphotericin B causes leaks into cells by combining with sterols in the plasma membrane. Would you expect to use amphotericin B against a bacterial infection? A fungal infection? Offer a reason why amphotericin B has severe side effects in humans.
- You can smell sulfur when boiling eggs. What amino acids do you expect in the egg? The smell of sulfur when boiling eggs is primarily due to the release of sulfur- containing compounds, specifically hydrogen sulfide (H₂S), which has a characteristic rotten egg odor. This smell originates from the sulfur atoms present in certain amino acids that are found in the proteins of the egg.
