The nitrogenase enzyme complex fixes N2 produces ammonia, The nitrogenase enzyme complex catalyzes this reaction by following characteristics given below;

a) It can be separated into two components—the Fe protein and the MoFe protein— neither of which has catalytic activity by itself

b) Fe protein is the smaller of the two components and has two identical subunits, each contains an iron–sulfur cluster, which participates in the redox reactions

c) The Fe protein is irreversibly inactivated by O2 while MoFe protein is activated by O2

d) MoFe protein has four subunits, each subunit has two Mo–Fe–S clusters

e) Ferredoxin serves as an electron donor to the Fe protein, and Fe protein reduces the MoFe protein without any hydrolysing ATP

f) Only prokaryotes have nitrogenase enzyme

Which of the following characteristics of nitrogenase enzyme complex is incorrect?

#Question id: 11088

#Unit 7. System Physiology – Animal

At a fraternity party a 17-year-old male places a paper bag over his mouth and breathes in and out of the bag. As he continues to breathe into this bag, his rate of breathing continues to increase. Which of the following is responsible for the increased ventilation?

#Question id: 11087

#Unit 7. System Physiology – Animal

Which of the following oxygen-hemoglobin dissociation curves corresponds to normal blood (red line) and blood containing carbon monoxide (green line)?

#Question id: 11086

#Unit 7. System Physiology – Animal

A 17-year-old female was bicycling without a helmet when she fell and hit her head. In the emergency room, she was not conscious and was receiving ventilator assistance. Her blood gases follow:

PaO2 = 52 mm Hg,

PaCO2 = 75 mm Hg, pH = 7.15, and

HCO3− = 31 mM

The majority of the CO2 was being transported as

#Question id: 11085

#Unit 7. System Physiology – Animal

The diagrams show changes in the partial pressures of oxygen and carbon dioxide as blood flows from the arterial end to the venous of the pulmonary capillaries. Which diagram best depicts the normal relationship between Po2 (red line) and Pco2 (green line) during resting conditions?

#Question id: 11084

#Unit 7. System Physiology – Animal

The next diagram shows two lung units (S and T) with their blood supplies. Lung unit S has an ideal relationship between blood flow and ventilation. Lung unit T has a comprised blood flow. What is the relationship between alveolar dead space (DALV), physiologic dead space (DPHY) and anatomic dead space (DANAT) for these lung units?

#Question id: 11083

#Unit 7. System Physiology – Animal

A 55-year-old male has a pulmonary embolism that partially blocks the blood flow to his right lung. Which point on the ventilation-perfusion line of the O2-CO2 diagram corresponds to the alveolar gas of his right lung?