General microbiology week 2 part I – Flashcards

1/ Which statement below demonstrates why the majority of organisms are heterotrophs? a) The majority of organisms conserve energy from inorganic sources. b) The majority of organisms obtain their carbon from organic sources. c) The majority of organisms conserve energy from inorganic sources and their carbon from organic sources. d) The majority of organisms obtain their carbon from inorganic sources.

2/ Based on the functional roles of phosphate in various microbial metabolisms, deduce which compounds phosphate exists as in microorganisms. a) both organic and inorganic compounds b) neither organic nor inorganic compounds c) organic compounds d) inorganic compounds

3/ Select the correct statement from the following: a) Plasmids are able to replicate independently of the bacterial chromosome. b) Plasmids are small, closed, circular, double stranded DNA. c) Plasmids can carry genes that confer a selective trait and move between different bacteria. d) All of the above.

4/ In group translocation glucose becomes phosphorylated as it enters a cell. a) True. b) False.

5/ The cytoplasmic membrane is termed "semi-permeable" because some substances, like water and alcohols, can pass freely through while others, like sugars, amino acids, and ions, cannot. What molecular characteristics largely determine whether or not a substance can pass through the membrane? a) organic versus inorganic molecules b) osmolarity c) size and hydrophobicity d) usefulness to the cell

6/ Trace elements are found in bacterial cells in very small amounts because they __________. A) are toxic to the cell B) are only found in limited quantities in the environment C) function only in a limited set of enzymes and cofactors D) are not essential to cell function

7/ To ensure growth of a newly discovered bacterium with unknown nutritional requirements, it would be best to begin with a ________ medium rather than a ________ medium. A) minimal / complex B) complex / minimal C) selective / differential D) selective / complex

8/ Which is an example of a micronutrient? A) arginine B) iron C) inorganic phosphorous D) vitamin B12

9/ For a carbon source, chemoorganotrophs generally use compounds such as A) acetate, succinate, and glucose. B) bicarbonate and carbon dioxide. C) nitrate and nitrite. D) acetate, bicarbonate, and nitrate.

10/ Cellular inclusions in prokaryotic cells serve to A) position cells in the appropriate environment for survival. B) protect DNA. C) store energy rich compounds. D) store energy rich compounds and position cells in the appropriate environment for survival.

11/ Aquaporins are a) cations bound to water molecules. b) molecules that prevent water from crossing a membrane. c) water transport proteins. d) enzymes involved in the generation of water within cells.

12/ A chemoorganotroph and a photoautotroph in the same environment would NOT compete for a) oxygen. b) nitrogen. c) carbon. d) carbon and oxygen.

13/ Nutrient transport requires energy because the nutrients must be transported into the cell against a concentration gradient. The energy required for nutrient transport is supplied by a) ATP, the proton motive force, or phosphoenol pyruvate. b) ATP. c) phosphoenol pyruvate. d) the proton motive force.

14/ 80S ribosomes can be found in both prokaryotes and eukaryotes. True False

15/ Small acid-soluble proteins (SASPs) protect DNA from ultraviolet light and are found in high numbers within a) endospores. b) inclusion bodies. c) gram-positive Bacteria. d) gram-negative Bacteria.

16/ Why is no energy required in passive transport? a) Transport proteins move the molecules, so no energy is required. b) The concentration gradient drives the movement. c) The membrane physically moves the molecules.

17/ Once equilibrium is reached, a) passive transport starts over to create a concentration gradient. b) molecules move, but there is no net movement in a particular direction. c) the membrane permits all molecules to freely move across the membrane. d) molecules no longer move.

18/ Which of the following would not move freely across the cytoplasmic membrane? a) Positively charged hydrogen ions b) Dissolved carbon dioxide c) Small alcohols d) Dissolved oxygen

19/ Which element functions BOTH as an enzyme cofactor and as a stabilizer of ribosomes and nucleic acids? a) magnesium b) iron c) zinc d) hydrogen