Choose the correct statements

a. Secondary structures are stabilized by hydrogen bonds.

b. Hydrogen bond always formed between non bonded atoms.

c. the folded length of an amino acid in α-helix reduced almost 3 times than linear structure.

d. Only dihedral angle changes during the formation of secondary structure while bond length remains unchanged

#Question id: 2457

#Unit 2. Cellular Organization

The two proteins that play the most important role in actin microfilament elongation are:

#Question id: 3982

#Unit 3. Fundamental Processes

The diagram below represents a hypothetical operon in the bacterium E. coli.  The operon consists of two structural genes (A and B) that code for the enzymes A-ase and B-ase, respectively, and also includes P (promoter) and O (operator) regions as shown.

 When a certain compound (X) is added to the growth medium of E. coli, the separate enzymes A-ase and B-ase are both synthesized at a 50-fold higher rate than in the absence of X (which has a molecular weight of about 200).  Which one of the following statements is true of such an operon?

#Question id: 5033

#Unit 11. Evolution and Behavior

Which of the following statements is correct in regard to Homo erectus?

#Question id: 2801

#Unit 2. Cellular Organization

In which phase of the eukaryotic cell cycle is the DNA in its most highly condensed form.

#Question id: 441

#Unit 1. Molecules and their Interaction Relevant to Biology

ATP is classified as an energy-rich compound because