Question

7. Which of the following reactions is involved with causing the pH to rise during a biochemical test? a. Protein catabolism to amino acids b. Deamination of amino acids c. NH, + H, O NHA + OH d. All of the above 8. Which of the following statements is correct regarding the biochemical tests you will be using to identify your unknown bacteria? a. Media prepared in the laboratory is not intended to duplicate an organism's natural environment. b. Media are spiked with a specific sugar or other substrate to manipulate an organism to change pH. c. Organisms do not normally alter the pH of their environment but can be manipulated to do so. d. All of the above 9. If an organism is obtaining energy from an organic molecule using either respiration or fermentation, which of the following types of organism is it (see Chapter 6 of the textbook)? a. Photoautotroph b. Photoheterotroph c. Chemoheterotroph d. Chemoautotroph 10. Which of the following is a correct sequence of events for cellular respiration (see Chapter 5)? A. Glycolysis, Krebs cycle, Preparatory step. Electron transport chain, Oxidative phosphorylation B. Glycolysis, Preparatory step, Krebs cycle, Oxidative phosphorylation, Electron transport chain C. Glycolysis, Preparatory step, Krebs cycle, Electron transport chain, Oxidative phosphorylation D. Preparatory step, Krebs cycle, Glycolysis, Electron transport chain, Oxidative phosphorylation Preparatory step of events for cel is, Preparatory 11. Which of the following is occurring if oxygen is the final electron acceptor in the electron transport chain and oxidative phosphorylation (see Chapter 5)? a. Aerobic respiration b. Anaerobic respiration e. Fermentation d. Any of the above could be correct 12. Which of the following is occurring if oxygen is not the final electron acceptor in the electron transport chain and oxidative phosphorylation but respiration is still occurring (see Chapter 5)? a. Aerobic respiration b. Anaerobic respiration c. Fermentation d. Any of the above could be correct 13. Which of the following is occurring if pyruvic acid produced during the oxidation of glucose during glycolysis acts as the final electron acceptor (keeping glycolysis going) and the ETC does not occur? a. Aerobic respiration b. Anaerobic respiration c. Fermentation. d. Any of the above could be correct

Answer 1

Answer 7: reaction that will lead to rise in pH in a biochemical test is “ B” Deamination of amino acids.

Various amino acids in peptone , yeast extract etc will under go microbial activity and lead to Deamination of amino acids which in turn will produce alkaline products.

Answer 8: “B” media are spiked with specific sugar or other substrate to manipulate a organism to change pH.

Media are spiked with a specific sugar or substrate so that the organism can be classified or identified on basis of ability to utilize a particular sugar. E.g. triple sugar Iron media.

Answer 9: “C “Chemoheterotroph”.

They obtain energy from an organic source e.g. by degradation of carbhydrates, proteins, lipids etc.

Answer 10: “C “Glycolysis, preparatory step, Kerb’s cycle, ETC, Oxidative Phosphorylation.

Energy released when the electrons are transferred in ETC is used to create a proton gradient which lead to Phosphorylation of ADP , hence ETC is before oxidative Phosphorylation .

Answer 11: “A “aerobic respiration.

As oxygen is a terminal electron acceptor, the respiration is aerobic.

Answer 12: “B “anaerobic respiration

Instead of Oxygen, other electron acceptors are used for e.g. Nitrate ions. Hence the answer.

Answer 13: “C “fermentation “

In fermentation Pyruvate is used as the terminal electron acceptor and NADH generated in process of Glycolysis is used as reducing agent.