Parietal cells acidify the stomach contents while maintaining a neutral cytosolic pH by: 

a. exporting “excess” cytosolic OH– as HCO3–.
b. exchanging HCO3– for Cl–.
c. preserving electroneutrality by accompanying the movement of each Cl– ion into the stomach lumen by a K+.
d. the excess K+ ions pumped inward by the H+/K+ ATPase are returned to the stomach lumen, thus maintaining the normal intracellular K+ concentration.
Which of the following combination is correct?

TLS Online TPP Program

#Question id: 33909

#Unit 2. Cellular Organization

What is the Lk of a 5,000 bp circular duplex DNA molecule with a nick in one strand?

TLS Online TPP Program

#Question id: 33910

#Unit 2. Cellular Organization

What is the Lk of a 5,000 bp circular duplex DNA molecule after eight enzymatic turnovers by a single molecule of DNA gyrase in the presence of ATP?

TLS Online TPP Program

#Question id: 33911

#Unit 2. Cellular Organization

What is the Lk of a 5,000 bp circular duplex DNA molecule after eight enzymatic turnovers by a single molecule of DNA gyrase in the presence of ATP followed by 8 enzymatic turnovers by a single molecule of bacterial type I topoisomerase

TLS Online TPP Program

#Question id: 33912

#Unit 2. Cellular Organization

A. When a DNA molecule is negatively supercoiled, it is underwound. 

B. Any structural change involving DNA strand separation becomes more likely in negatively supercoiled DNA. 

C. Negative supercoiling makes establishment of left-handed Z-DNA in a segment of DNA 

D. The formation of plectonemic or solenoidal supercoils is favored as a means of negative supercoiling.

Find true and false

TLS Online TPP Program

#Question id: 33913

#Unit 2. Cellular Organization

A. Underwinding of a B-DNA helix might facilitate or stabilize the formation of Z-DNA.

B. Underwinding aids in the transition by providing a local region of unwound DNA that allows the shift to Z-DNA.

C. Overwinding of a B-DNA helix might facilitate or stabilize the formation of Z-DNA.

D. Overwinding aids in the transition by providing a local region of unwound DNA that allows the shift to Z-DNA.

What is correct combination of statements

TLS Online TPP Program

#Question id: 33981

#Unit 2. Cellular Organization

The scaffold-associated regions are separated by loops of DNA. The scaffold itself may contain several proteins such as

A. Topoisomerase

B. SMCs

C. RNA Polymerase