Final (Exams I Questions) – Flashcards

A(n) _______ inhibitor will bind to an enzyme's _______ site, changing the enzymes conformation so that substrate molecules can no longer bind to the active site. A. competitive; actice B. noncompetitive; allosteric C. allosteric; active D. competitive; allosteric E. noncompetitive; active

Which of the following statements concerning enzymes is false? a. an enzymes amino acid composition will determine its conformation and active site structure b. at temperatures above or below an enzymes temperature optimum, the active site will change shape, allowing for recognition of alternative substrates c. enzymes may be denatured by increasing or lowering the ionic strength of its environment d. enzymes lower the energy necessary to reach a reaction's transition state, thereby enhancing the rate of the reaction but not altering the equilibrium e. enzymes act as catalysts in that they participate in the reaction but are not consumed by the reaction

Which of the following can be the final electron receptor in anaerobic respiration by chemolithotrophic bacteria? a. ethanol b. pyruvate c. oxygen d. both nitrate and sulfate e. both pyruvate and nitrate

4) Sulfanilamide is an antimicrobial drug that mimics the shape of an important substrate for a particular enzyme, thereby inhibiting the enzyme. This type of inhibition is known as a. antagonistic inhibition. b. competitive inhibition. c. repulsive inhibition. d. uncompetitive inhibition. e. feedforward inhibition.

5) A Gram-negative opportunistic pathogen often associated with nosocomial infections that synthesizes a blue-green pigment and is commonly found in the environment is a. Escherichia coli. b. Pseudomonas aeruginosa. c. Staphylococcus aureus. d. Mycobacterium tuberculosis. e. None of the above.

6) You have isolated a bacterium from the sputum of a patient who has a bacterial infection of the lung. You have detected the presence of mycolic acids and other waxy lipids. Which of the following statements apply? a. The Gram stain should be used for diagnosis. b. You will need to use the Acid-fast stain for diagnosis. c. The bacterium is likely to be Mycoplasma d. You should use the negative stain technique for diagnosis. e. None of the above.

7) Compact compartments that protect RuBisCo from the oxygen produced during noncyclic photosynthesis are called a. chloroplasts. b. Calvin bodies. c. lysozomes. d. carboxysomes. e. rubiscomers.

8) Which of the following is FALSE about the bacterial cell wall? a. The peptidoglycan chain is made of alternating units of glucose-based N-acetylglucosamine and N acetylmuramic acid sugars. b. Endotoxins are lipopolysaccharides that are attached to the outer portion of the outer membrane of Gram-negative bacteria. c. The O-antigen is the membrane component that is often used to characterize Gram-positive bacteria. d. Differences in cell wall structures are the basis of the Gram stain. e. The integrity of the cell wall (and, by extension, the shape of the cell) is due, in part, to the peptidoglycan layer.

9) Which of the following statements concerning microbial cellular metabolism is FALSE? a. Enzymes are essential for catabolic and anabolic reactions. b. Metabolic precursors are transformed into macromolecules by anabolism. c. Reducing power from nutrients is captured by the hydrolysis of ATP. d. The main purpose of metabolism is reproduction of the organism. e. ATP is used in the formation of macromolecules.

10) Which of the following was NOT an aspect of Pasteur's experiments to disprove Spontaneous Generation? a. Starting with a liquid that contained microorganisms. b. Microbes only grew when the sterile broth contacted microorganisms from air. c. Only flasks open to air had microbial growth in them. d. The broths were boiled to sterilize them. e. Broths in the swan-necked flasks remained sterile for long periods of time even though air could get in

11) In the figure below, which picture represents the Gram-positive cell wall? a. a b. b c. both a and b d. neither a nor b e. The answer cannot be determined based on the information provided.

12) The atypical bacterium Mycoplasma pneumoniae causes a form of pneumonia. Which of the following is TRUE? a. Penicillin would be a good choice to treat a Mycoplasma infection. b. It forms endospores, which is only characteristic of atypical bacteria. c. Its shape is variable. d. It requires the Acid-Fast stain for identification, like all atypical bacteria. e. Lysozyme would affect actively growing Mycoplasma cells.

13) The bacterium shown below has no apparent nucleus and is purple after a Gram stain. This bacterium was also observed to move toward a carbon source for food. You could conclude all of the following EXCEPT: a. It is a Gram-negative bacillus. b. It has polar flagella. c. It exhibits chemotaxis. d. It has a cell wall. e. It is a Gram-positive bacillus.

14) The anabolism of sugars and other complex carbohydrates from fatty acids, amino acids, C02 or simple carbohydrates is accomplished by a. protease activity and amino group removal (by deaminases). b. gluconeogenesis. c. fermentation. d. the Calvin cycle. e. glycolysis.

For each of the cell structures specify whether it is true for: Most Sensitive to Penicillin a. Gram-positive bacteria b. Gram-negative bacteria c. Both Gram-negative and Gram-positive bacteria d. Neither Gram-negative nor Gram-positive bacteria

For each of the cell structures specify whether it is true for: ATP synthetase a. Gram-positive bacteria b. Gram-negative bacteria c. Both Gram-negative and Gram-positive bacteria d. Neither Gram-negative nor Gram-positive bacteria

For each of the cell structures specify whether it is true for: Outer Membrane a. Gram-positive bacteria b. Gram-negative bacteria c. Both Gram-negative and Gram-positive bacteria d. Neither Gram-negative nor Gram-positive bacteria

18) For each of the cell structures specify whether it is true for: Golgi bodies a. Gram-positive bacteria b. Gram-negative bacteria c. Both Gram-negative and Gram-positive bacteria d. Neither Gram-negative nor Gram-positive bacteria

19) For each of the cell structures specify whether it is true for: Thick layer of peptidoglycan a. Gram-positive bacteria b. Gram-negative bacteria c. Both Gram-negative and Gram-positive bacteria d. Neither Gram-negative nor Gram-positive bacteria

20) Fermentation is a metabolic process that a. requires the Krebs cycle for its energy and reducing power. b. is an alternative to the Calvin cycle. c. may use ribose and glucose as final electron acceptors. d. occurs only when oxygen is readily available. e. is dependent on reducing power that is generated by glucose oxidation.

21) Anabolic reactions a. are exergonic. b. require reducing power and ATP. c. include cyclic pathways that release C02 . d. generate reducing power in the form of FADH2 and coenzyme QH2. e. produce small precursor molecules from large molecules

22) For the name Staphylococcus aureus, "aureus" is the a. genus. b. domain name. c. species. d. kingdom. e. family name.

23) A cancer-causing bacterial pathogen that avoids the acidic pH of the stomach by burrowing through the mucous layer and into epithelial cells that line the stomach is a. Mycobacterium tuberculosis. b. Escherichia coli. c. Bacillus anthracis. d. Helicobacter pylori. e. None of the above

24) Carl Woese a. discovered 16S and 18S rRNA sequences. b. proposed three Domains to classify all organisms based on their 16S and 18S rRNA sequences. c. proposed breaking eukaryotes into Domains Eukarya, Archaea, and Bacteria. d. was involved in refining the Gram stain for classification purposes. e. All of the above.

25) Which of the following statements concerning reduction reactions is FALSE? a. An electron acceptor gains an electron. b.They are coupled with oxidation reactions. c. They frequently involve electron carrier molecules. d. An electron acceptor becomes more positively charged. e. A molecule gains a hydrogen atom.

26) Which of the following statements about the light-dependent reactions of photosynthesis is NOT true? a. Production of ATP requires the participation of chlorophyll a and other light harvesting pigments. b. Cyanobacteria rely on photosystems I and II for reducing power and ATP. c. They are responsible for the production of reduced NADP. d. They provide the reducing power necessary for carbon fixation. e. Oxygenic photosystem 2 reactions may use hydrogen (H2) gas or hydrogen sulfide (H2S) as electron donors in place of water.

27) Which is NOT a function(s) of the cytoplasmic membrane in prokaryotes? a. It functions as a permeability barrier. b. It is a site for many proteins involved in transport. c. It is a major site of energy transformations. d. It plays a significant role in the generation of energy by substrate level phosphorylation. e. it is the location of the electron transport chain in most prokaryotes.

28 The following statements about oxidative phosphorylation are true, EXCEPT: a. Blocking the flow of protons and electrons through the chain will stop ATP synthesis. b. ATP synthesis utilizes the energy derived from the electron transport chain as well as the proton gradient. c. The final acceptor may be oxygen, with the formation of water. d. The protonmotive force generated by the electron transport chain may be used to power flagella and transport solutes (active transport). e. The process is a primary mechanism for regenerating reduced coenzymes for use in metabolic pathways.

29) In the figure below, which shows a sarcinae arrangement? a. A b. B c. C d. D e. Not shown.

30) Starting with an inoculum of 10 cells, how many bacteria would there be after 3 hours with a doubling time of 30 minutes? a. 640 b. 160 c. 120 d. 900 e. 320

31) If a microbiology lab technician left the decolorizer out of the Gram stain procedure, what would be the most likely result? a. All cells would be purple. b. Gram-positive cells would be purple and Gram-negative cells would be colorless c. All cells would be pink. d. Gram-positive cells would be pink and Gram-negative cells would be purple. e. Gram-positive cells would be colorless and Gram-negative cells would be pink.

35) The portion of the bacterial growth curve that a culture is most sensitive to antibiotics is a. lag phase b. stationary phase c. exponential phase d. metaphase e. prophase

33) The following statements about the pentose phosphate pathway are true, EXCEPT: a. The pathway is an alternative route for glucose oxidation. b. Reducing power is an important product of the pentose phosphate pathway c. The pathway is a direct contributor of ATP via substrate-level phosphorylation reactions. d. The pathway is necessary for the synthesis of ribose-5-phosphate, which is important for nucleic acid synthesis. e. The pathway provides the cell with precursor molecules.

36) Which of the following statements is FALSE? a. Prokaryotic flagella are anchored to the cell wall by means of the basal body. b. Pili are involved in genetic exchange of DNA between prokaryotic cells. c. The glycocalyx may function in the formation of a biofilm. d. Fimbriae are generally longer and less numerous than flagella. e. Fimbriae of a bacterium may be used for adhering to surfaces or other cells

32) _______ is a member of the Actinomycetes- a group of bacteria that produce many of the antibiotics used today. a. Bacillus anthracis b. Streptomyces griseus c. Helicobacter pylori d. Clostridium botulinum e. Pseudomonas aeruginosa

37) The scientist who contributed most to the development of pure culture techniques was a. Alexander Fleming. b. Louis Pasteur. c. Selman Waksman . d. Robert Koch. e. None of the above.

38) Carbon dioxide is a by-product of which of the following? a. Calvin cycle b. Photophosphorylation c. Substrate-level phosphorylation d. TCA cycle e. None of the above

34) Which of these scientist(s) coined the term animalcule when observing a drop of pond water through a microscope? a. Redi b. van Leeuwenhoek c. Pasteur d. Hooke e. Koch

39) The following statements about Escherichia coli are true, EXCEPT: a. It possesses characteristic lophotrichous flagella. b. It is a member of the gammaproteobacteria , which includes many pathogenic enterobacteria. c. It is a Gram-negative facultative anaerobe. d. It can be selectively grown on MacConkey agar, and is differentiated on this agar by its pink colony color. e. It is commonly found in the lower intestine of warm-blooded animals and provides its host with vitamins.

40) Which of the following statements concerning glycolysis is TRUE? a. Glycolysis utilizes the NADH that is generated by the electron transport chain. b. Glycolysis enzymes are located within the inner membrane of bacteria. c. While glycolysis produces ATP, reducing power is generated by the TCA cycle. d. The glycolysis pathway is an alternative to fermentation . e. Glycolysis is an oxidation process that generates reduced coenzymes, ATP and metabolic intermediates used for biosynthesis.

41) What is NOT true about endospores? a. They are reproductive structures. b. They are resistant to extremes of temperature , UV irradiation, drying, and toxic chemicals . c. They are a survival mechanism for certain bacteria. d. They are produced by members of the genera Bacillus and Clostridium. e. Germination results in the emergence of a growing, reproducing, vegetative cell.

42) Which of the following substances are not produced by the TCA cycle? a. ATP b. Pyruvate c. FADH2 d. NADH+H+ e. Carbon dioxide