A product of the anterior pituitary gland that causes color changes in its target cells is ________.

#Question id: 870

#Unit 1. Molecules and their Interaction Relevant to Biology

Choose correct statements about ‘Protein Disulfide Isomerase’ in protein folding

A. Oxidized PDI catalyzes the rearrangement of a polypeptide’s non-native disulfide bonds via disulfide interchange reactions to yield native disulfide bonds.

B. Reduced PDI catalyzes the initial formation of a polypeptide’s disulfide bonds through the formation of a mixed disulfide.

C. Protein disulfide isomerase contains the conserved active site motif of Cys-Xaa-Xaa-Cys found in thioredoxin and shares a similar role to the Dsb family of proteins found in E. coli.

D. Under more reducing conditions with thiols in the active site the enzyme reshuffles disulfides (isomerase) in target proteins.

#Question id: 871

#Unit 1. Molecules and their Interaction Relevant to Biology

According to ‘Energy–entropy phenomenon’ for protein folding correct combinations of possible conformations

#Question id: 872

#Unit 1. Molecules and their Interaction Relevant to Biology

Which of the following statements is not true about HSP 70 family.

A. They have a molecular weight near 70,000 and are abundant in cells stressed by elevated temperature.

B. Bind to regions of unfolded polypeptides that are rich in hydrophilic residues

C. Hsp70 proteins not  block the folding of certain proteins that must remain unfolded untill they have been translocated across a membrane.

D.) It releases polypeptides in a cycle that uses energy from ATP hydrolysis.

#Question id: 873

#Unit 1. Molecules and their Interaction Relevant to Biology

Intrinsically disordered proteins have properties that are distinct from classical structured proteins

A. Are characterized by sequences rich in certain polar and charged amino acids (Gln, Ser, Pro, Glu, Lys, Gly, and Ala)

B. Ordered proteins tend to participate in signaling and regulation, whereas Intrinsically disordered proteins are involved largely in catalytic reactions, transport processes, and structural functions.

C. Nearly half of all prokaryotic proteins contain long disordered segments, whereas only a few percent of eukaryotic proteins do.

D. Often adopt a specific secondary or tertiary structure when they bind to other molecules such as ions, organic molecules, proteins, and nucleic acids.

#Question id: 874

#Unit 1. Molecules and their Interaction Relevant to Biology

Fates of misfolded proteins, according given figure

#Question id: 875

#Unit 1. Molecules and their Interaction Relevant to Biology

Why positive phi angles less common than negative Phi angles in proteins contain L amino acid?