Nitrate reductase is an important enzyme for nitrate assimilation. Given below some regulation of nitrate reductase activity through phosphorylation and dephosphorylation.

a) Light, and other environmental factors stimulate a protein phosphatase that dephosphorylates a key serine residue in the hinge 1 region of nitrate reductase and thereby activates the enzyme

b) In Dark, and Mg2+ stimulate a protein kinase that phosphorylates the same serine residues, which then interact with a 14-3-3 inhibitor protein, and thereby inactivate nitrate reductase

c) In Light, and Mg2+ stimulate a protein kinase that phosphorylates the serine residues, and thereby activate nitrate reductase

d) In Dark, and other environmental factors stimulate a protein phosphatase that dephosphorylates a key serine residue in the hinge 1 region of nitrate reductase and thereby inactivates the enzyme

Which of the following statements about regulation of nitrate reductase is correct?

#Question id: 10942

#Unit 7. System Physiology – Animal

A 45-year-old man presents to the emergency room with a 2-week history of diarrhea that has gotten progressively worse over the last several days. He has minimal urine output and is admitted to the hospital for dehydration. His stool specimen is positive for parasitic eggs. Which type of WBCs would have an elevated number?

#Question id: 10943

#Unit 7. System Physiology – Animal

An 8-year-old male is frequently coming to the clinic for persistent skin infections that do not heal within a normal time frame. He had a normal recovery from the measles. Checking his antibodies following immunizations yielded normal antibody responses. A defect in which of the following cells would most like be the cause of the continual infections?

#Question id: 10944

#Unit 7. System Physiology – Animal

Where does the transmigration of WBCs occur in response to infectious agents?

#Question id: 10945

#Unit 7. System Physiology – Animal

A 65-year-old alcoholic developed chest pain and cough with an expectoration of sputum. A blood sample revealed that his white blood cell count was 42,000/μl. What is the origin of these WBCs?

#Question id: 10946

#Unit 7. System Physiology – Animal

A 26-year-old man received a paper cut. What substance is the major cause of pain of this acute inflammatory response?

#Question id: 10947

#Unit 7. System Physiology – Animal

What occurs following activation of basophils?