Dichlorodiphenyltrichloroethane is related to the phenomenon of:

#Question id: 4146

#Part-A Aptitude & General Biotechnology

Approximately how many NTPs must be converted to NDPs to incorporate one amino acid into a protein?

#Question id: 1641

#Part-B Specialized Branches in Biotechnology

Why are secondary antibody responses better?

#Question id: 4379

#Part-A Aptitude & General Biotechnology

Bromodomains are found in chromosome-associated proteins that contribute to transcriptional activation. To facilitate this activation, the bromodomains bind to histones, specifically their lysine residues that have been post-translationally modified by:

#Question id: 723

#Part-B Specialized Branches in Biotechnology

Common structural elements in proteins such as α-helices or β-sheets are characterized by uniformly repeating, energetically favorable main chain conformations which additionally exhibit a completely saturated hydrogen-bonding network of the main chain NH and CO groups. Although polyproline or polyglycine type II helices (PPII or PGII ) are frequently found in proteins, they are not considered as equivalent secondary structure elements. Which of the following statements are correct about PP and PGs.

A. PGII -like helices form hexagonal bundles which appear to fulfill the criterion of a (largely) saturated hydrogen-bonding network of the main-chain groups

B. main chain NH and CO groups of the central PGII -helix are saturated by either intra- or intermolecular hydrogen-bonds, resulting in a self-contained hydrogen-bonding network

C. The formation of the right-handed PPI helix is possible only with proline residues because of the required cis conformation. 

D. PPII helices seem to be stabilized by main chain-water hydrogen bonds (in the absence of main chain- main chain H-bonds), and tend to have a regular pattern of hydrogen bonds with water. After this, it is not surprising, that PPII helices are found mostly on the protein surface.

#Question id: 14336

#Part-B Specialized Branches in Biotechnology

A cylindrical stirred bioreactor of diameter and height 2 m has a Rushton turbine one-third the tank diameter in size. The bioreactor contains Newtonian culture broth with the same density as water and with viscosity 4 cP. The tank is now aerated. In the presence of gas bubbles, the approximate relationship between ungassed power number (N_P)₀ and gassed power number (N_P)g is: (N_P)g =0.5 (N_P)₀. What maximum stirrer speed is now possible in the sparged reactor? Estimate the mixing time.