Practice Questions

  1. Home
  2. Free Resources
  3. Practice Questions
  4. 54993
TLS Online TPP Program

#Question id: 14766

Which of the following statements does not belongs to the regulatory mechanism of the Arp2/3 complex by WASp and PI(4,5)P2?

#Unit 2. Cellular Organization
  1. The NPF WASp is inactive due to an intramolecular interaction that masks the WCA domain. 
  2. NPF WASp is activated by a coincidence detection mechanism, it must bind both the regulatory phospholipid PI(4,5)P2 though its basic domain (B) and the membrane-bound active small G protein Cdc42-GTP through its Rho-binding domain. 
  3. When activated by the Cdc42-GTP, the intramolecular interaction in WASp is relieved, allowing the W domain to bind actin and the acidic A domain to activate the Arp2/3 complex.
  4. The Arp2/3 branch makes a characteristic 70° angle between the old and new filaments.
More Questions
TLS Online TPP Program

#Question id: 24208

#Unit 1. Molecules and their Interaction Relevant to Biology

What is the true substrate for hexokinase
TLS Online TPP Program

#Question id: 14146

#Unit 1. Molecules and their Interaction Relevant to Biology

Match the following

A. Cyanide 1. Inhibit cytochrome oxidase

B. Piericidin A 2. Prevent electron transfer from Fe-S center to ubiquinone

C. Antimycin A 3. Blocks electron transfer from cytochrome b to cytochrome c1

D. Valinomycin 4. K+ ionophore
TLS Online TPP Program

#Question id: 543

#Unit 1. Molecules and their Interaction Relevant to Biology

If glucose labeled with 14C at C-1 (the aldehyde carbon) were metabolized in the liver, the first radioactive pyruvate formed would be labeled in:
TLS Online TPP Program

#Question id: 542

#Unit 1. Molecules and their Interaction Relevant to Biology

Hamsters love to run on exercise wheels. Prolonged running at a high rate of speed requires ATP. Could a hamster with a defective gene for the enzyme lactate dehydrogenase meet the extra ATP demand for prolonged, fast wheel-running by maintaining a high rate of glycolysis? Why or why not?
TLS Online TPP Program

#Question id: 541

#Unit 1. Molecules and their Interaction Relevant to Biology

The overall △G for glycolysis is -72 kJ/mol in erythrocytes. Which statement below is true?

A) The value of △G0ʹ is also -72 kJ/mol since the cytosol pH is close to 7.

B) The free energy of glycolysis is found as the sum of the standard free energy changes for

the individual pathway reactions.

C) The negative sign of △G shows that this pathway will proceed toward product (pyruvate) under normal cellular conditions.
TLS Online TPP Program

#Question id: 540

#Unit 1. Molecules and their Interaction Relevant to Biology

During strenuous exercise, the NADH formed in the glyceraldehyde 3-phosphate dehydrogenase reaction in skeletal muscle must be reoxidized to NAD+ if glycolysis is to continue.  The most important reaction involved in the reoxidation of NADH is: