Practice Questions

  1. Home
  2. Free Resources
  3. Practice Questions
  4. 24852
TLS Online TPP Program

#Question id: 3021

The lag phase of the bacterial growth curve is marked by

#Part-B Specialized Branches in Biotechnology

  1. a decrease in cell mass.

  2. dormant, metabolically inactive cells.

  3. metabolically active cells.

  4. vigorously dividing cells.

More Questions
TLS Online TPP Program

#Question id: 7458

#Part-A Aptitude & General Biotechnology

An accurate clock shows 8 o’ clock in the morning . Through how many degrees will the hour hand rotate when the clock shows 2 o’ clock in the afternoon ?
TLS Online TPP Program

#Question id: 1729

#Part-A Aptitude & General Biotechnology

When a resting naive T-cell engages its specific MHC–peptide complex displayed on the surface of a fibroblast, it:
TLS Online TPP Program

#Question id: 14133

#Part-A Aptitude & General Biotechnology

The study of evolutionary relationships is known as
TLS Online TPP Program

#Question id: 14537

#Part-B Specialized Branches in Biotechnology

 evaluates to
TLS Online TPP Program

#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.