Practice Questions

  1. Home
  2. Free Resources
  3. Practice Questions
  4. 55806
TLS Online TPP Program

#Question id: 10463

LOV1 and LOV2, each binding a chromophore flavin mononucleotide (FMN), which one of the following statements shows incorrect prediction about LOV domains?

#Unit 6. System Physiology – Plant
  1. Upon blue-light illumination, the FMN molecule becomes covalently bound to a cysteine residue in the phototropin molecule, forming a cysteine-flavin covalent adduct
  2. Phototropin contains two light-sensing LOV domains, the LOV1 domain is primarily responsible for kinase activation in response to blue light
  3. The three-dimensional structure of the LOV2 domain resembles a closed molecular hand holding the FMN tightly by noncovalent interactions inside its core
  4. In the dark, one FMN molecule is noncovalently bound to each LOV domain
More Questions
TLS Online TPP Program

#Question id: 733

#Unit 1. Molecules and their Interaction Relevant to Biology

Which one of the statements on protein conformation, detailed below is INCORRECT?
TLS Online TPP Program

#Question id: 732

#Unit 1. Molecules and their Interaction Relevant to Biology

Ramachandran plots can help increase the accuracy of models derived from x-ray crystallography data. The plot below was created by measuring phi, and psi for each amino acid residue in a 2.2 A resolution crystal structure. In the plot, which excludes Gly and Pro residues, selected residues (dots) are numbered 1 through 5.

Which of the following statements can be correctly stated for this plot in reference to selected residues?

A. Residues 1 and 3 are in either B sheets

B. residue 2 is in a right-handed a helix, and residue 4 is in a left-handed a helix.

C. If residue 5 were Gly, it might be in an acceptable position in the plot
TLS Online TPP Program

#Question id: 731

#Unit 1. Molecules and their Interaction Relevant to Biology

Which of the following structure is mentioned in the given Ramachandran plot
TLS Online TPP Program

#Question id: 729

#Unit 1. Molecules and their Interaction Relevant to Biology

Which of the following is correct about the collagen triple-helix domain

a. is rich in glycine.                             b. is rich in proline.

c. is rich in hydroxyproline.                d. is an alpha helix.
TLS Online TPP Program

#Question id: 728

#Unit 1. Molecules and their Interaction Relevant to Biology

Match the following tile peaks with corresponding circular dichroism spectra

A. Alpha helix

I. negative bands at 222 nm and 208 nm and a positive one at 190 nm.

B. Beta sheet

II. negative band at 218 nm and a positive one at 196 nm.

C. Random coil

III. positive band at 212 nm and a negative one around 195 nm.

TLS Online TPP Program

#Question id: 727

#Unit 1. Molecules and their Interaction Relevant to Biology

26-residue peptide composed of alanine and leucine shows a circular dichroism (CD) spectrum characteristic of α-helix at 50°C in 5 mM phosphate buffer at pH 7.4. When the peptide solution is cooled gradually to 25°C, and the CD spectra are recorded at different temperatures, the most likely observation will be that