#Question id: 3472
#Unit 11. Evolution and Behavior
Which of the following is incorrect statement?
#Question id: 28293
#Unit 5. Developmental Biology
Which enzyme used in the former cortical granule membrane catalyzes the formation of hydrogen peroxide?
#Question id: 23565
#Unit 8. Inheritance Biology
#Question id: 723
#Unit 1. Molecules and their Interaction Relevant to Biology
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: 11604
#Unit 6. System Physiology – Plant
What will be the effect of exogenous gibberellin in plant?
a) extreme stem elongation in dwarf plants
b) Increases in stem
thickness
c) decrease in leaf size
d) decreases in stem thickness
e) Increases in leaf size
f) pale green color of the leaves