🦠 Microbiology Solved MCQs with Answers

Practice 1927 approved 🦠 Microbiology questions with verified answers from the 🧬 Medical Science subject for Pakistan exams.

1927 solved MCQs

The bacteriochlorophylls used by the anoxygenic bacteria have absorbance maxima located in the_____portion(s) of the spectrum.Answer: infrared The relationship between an oxidation-reduction potential difference and the standard free energy change is (where n is the number of moles of electron transferred, F= Faraday's constant and E°= standard oxidation-reduction potential difference)Answer: ΔG° = -nFE° ATPaseAnswer: carries out each of the reactions indicated in (a) and (b) Which of the following is responsible for phosphate solubilization?Answer: Bacillus Phosphate deregulated mutants areAnswer: less sensitive to phosphate regulation The mechanism of passive or facilitated diffusion requireAnswer: metabolic energy Nitrogen fixation is a process that requiresAnswer: both (a) and (b) Bacteriochlorophyll differs from chlorophyll in what way?Answer: Both (b) and (c) Radioisotopes are frequently used in the study of cells. Assume a culture of E. coli is grown in a culture medium containing radioactive sulphur. At the end of 48 hours, it is expected to find the radioactive label located inAnswer: enzymes Organisms can synthesize ATP by oxidative phosphorylation when theyAnswer: pass electrons to oxygen through an electron transport system containing cytochromes How many molecules of carbon dioxide will be given off during ten turns of the Krebs cycle?Answer: 20 In cellular metabolism, O₂ is usedAnswer: as a terminal electron acceptor In glycolysis, ATP is created byAnswer: substrate level phosphorylation Suppose a eukaryotic cell had a mutation that prevented the production of cytochrome c. As a result of this mutation, which of the following processes would not occur?Answer: Cellular respiration Which of the following best explains about the usefulness of the production of ethanol in yeast cells under anaerobic conditions?Answer: The process regenerates NAD⁺, which is required for glycolysis The final electron acceptor in the electron transport chain isAnswer: oxygen The amount of energy (cal/mole) in an ATP molecule produced by a cell from glucose by fermentation isAnswer: exactly or approximately equal to aerobic metabolism The enzymes for glycolysis are locatedAnswer: in the cytoplasm Glucose can be broken down to pyruvate byAnswer: Entner-Doudoroff pathway In lactic acid fermentation, the final electron acceptor would beAnswer: pyruvate The amount of ATP that can be obtained by complete oxidation of a glucose by a bacterium isAnswer: greater than by a yeast cell Which of the following is accomplished in chemiosmosis?Answer: The oxidation of NADH A yeast or fungal cell produces how many net ATP molecules per molecule of glucose when completely oxidized?Answer: 36 Before most molecules can enter the Krebs citric acid cycle, they must be converted toAnswer: acetyl-CoA How many oxygen molecules are required in the fermentation of one molecule of glucose to ethanol and CO₂?Answer: 0 Most bacterial fermentations yield how many net ATP molecules per molecule of glucose?Answer: 2 The amount of ATP produced by a cell from glucose when metabolizing it by fermentation means isAnswer: lesser than by aerobic metabolism Which one of the following is produced in the greatest numbers during one turn of the Krebs cycle?Answer: NADH Aerobic respiration differs from anaerobic respiration in which of the following respects?Answer: The final electron acceptors are different For each pair of electrons passing from NADH located inside the mitochondria to oxygen, how many ATP molecules can be generated?Answer: 3