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TLS Online TPP Program

#Question id: 10308

Oxidative decarboxylation of pyruvate to acetyl-CoA by the PDH complex, how the pyruvate dehydrogenase complex carries out the five consecutive reactions in the decarboxylation and dehydrogenation of pyruvate?

 A) Pyruvate reacts with the bound thiamine pyrophosphate (TPP) of pyruvate dehydrogenase, undergoing decarboxylation to the hydroxyethyl derivative

 B) A transesterification in which the —SH group of CoA replaces the —SH group of E2 to yield acetyl-CoA and the fully reduced (dithiol) form of the lipoyl group

 C) The reduced FADH2 of E3 transfers a hydride ion to NAD1 , forming NADH, the enzyme complex is now ready for another catalytic cycle

 D) The transfer of two electrons and the acetyl group from TPP to the oxidized form of the lipoyllysyl group of the core enzyme, dihydrolipoyl transacetylase, to form the acetyl thioester of the reduced lipoyl group

 E) Dihydrolipoyl dehydrogenase promotes transfer of two hydrogen atoms from the reduced lipoyl groups of E2 to the FAD prosthetic group of E3 , restoring the oxidized form of the lipoyllysyl group of E2

 Find out the correct sequence of action of this complex enzyme?

#Unit 6. System Physiology – Plant
  1. E→C→B→E→D
  2. A→D→B→E→C
  3. E→B→D→A→C
  4. D→A→E→B→C
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TLS Online TPP Program

#Question id: 12388

#Unit 7. System Physiology – Animal

Which of the following has similar values for both intracellular and interstitial body fluids?
TLS Online TPP Program

#Question id: 12387

#Unit 7. System Physiology – Animal

An elderly patient complains of muscle weakness and lethargy. A urine specimen reveals a Na+ concentration of 600 mmol/L and an osmolarity of 1200 mOsm/L. Additional laboratory tests provide the following information: plasma Na+ concentration = 167 mmol/L, plasma renin activity = 4 ng angiotensin I/ml/hr (normal = 1), plasma antidiuretic hormone (ADH) = 60 pg/ml (normal = 3 pg/ml), and plasma aldosterone = 15 ng/dL (normal = 6 ng/dL). Which of the following is the most likely reason for this patient’s hypernatremia?
TLS Online TPP Program

#Question id: 12386

#Unit 7. System Physiology – Animal

Which of the following changes would you expect to find in a patient who developed acute renal failure after ingesting poisonous mushrooms that caused renal tubular necrosis?
TLS Online TPP Program

#Question id: 12385

#Unit 7. System Physiology – Animal

To evaluate kidney function in a 45-year-old woman with type II diabetes, you ask her to collect her urine over 24 hours. She collects 3600 ml of urine in that period. The clinical laboratory returns the following results after analyzing the patient’s urine and plasma samples: plasma creatinine = 4 mg/dL, urine creatinine = 32 mg/dL, plasma potassium = 5 mmol/L, and urine potassium = 10 mmol/L.
What is the net renal tubular reabsorption rate of potassium in this patient?
TLS Online TPP Program

#Question id: 12384

#Unit 7. System Physiology – Animal

To evaluate kidney function in a 45-year-old woman with type II diabetes, you ask her to collect her urine over 24 hours. She collects 3600 ml of urine in that period. The clinical laboratory returns the following results after analyzing the patient’s urine and plasma samples: plasma creatinine = 4 mg/dL, urine creatinine = 32 mg/dL, plasma potassium = 5 mmol/L, and urine potassium = 10 mmol/L.
What is this patient’s approximate GFR, assuming that she collected all her urine in the 24-hour period?
TLS Online TPP Program

#Question id: 12383

#Unit 7. System Physiology – Animal

Which of the following changes tends to increase urinary Ca++ excretion?