TLS Online TPP Program

#Question id: 12182


The cell cycle is controlled by protein kinases that comprise a catalytic subunit and a regulatory subunit. Which of the following statement is correct regarding to these subunits?

#Unit 2. Cellular Organization
  1. The catalytic subunits, the cyclin-dependent kinases (CDKs), have no kinase activity unless they are dissociated with a regulatory cyclin subunit. 
  2. Each CDK can associate with a small number of different cyclins, which determine the substrate specificity of the complex—that is, which proteins it phosphorylates.
  3. Cyclin-CDK complexes activate or inhibit hundreds of proteins involved in cell cycle progression by phosphorylating or dephosphorylating them at specific regulatory sites. 
  4. Proper progression through the cell cycle is governed by activation of the appropriate homodimeric protein kinase complex at the appropriate time.
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TLS Online TPP Program

#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)?

TLS Online TPP Program

#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


TLS Online TPP Program

#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?

TLS Online TPP Program

#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?


TLS Online TPP Program

#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?


TLS Online TPP Program

#Question id: 11082

#Unit 7. System Physiology – Animal

A 67-year-old man has a solid tumor that pushes against an airway partially obstructing air flow to the distal alveoli. Which point on the ventilation-perfusion line of the O2-CO2 diagram corresponds to the alveolar gas of these distal alveoli?