#Question id: 3023
#Part-B Specialized Branches in Biotechnology
During which phase of the bacterial growth curve does a bacterial population become much more resistant to harmful conditions?
#Question id: 11629
#Part-A Aptitude & General Biotechnology
Two pure line plants of 46 cm and 10 cm in height cross each other forming F1 progeny 28 cm in height, what is the no. of QTL formed?
#Question id: 10391
#Part-B Specialized Branches in Biotechnology
#Question id: 3017
#Part-B Specialized Branches in Biotechnology
Biofilms
#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.