A What are two advantages that the use of green fluorescent

A. What are two advantages that the use of green fluorescent protein (GFP) has over the use of fluorescent-labeled antibodies for studying the location and movement of a protein in cells?

B. What is meant by empty magnification when taking images on a microscope?

C. The lipid bilayers found in cells are fluid, yet asymmetrical in the composition of the monolayers. Is this a paradox? Explain your answer.

D. Why do transmembrane domains of proteins typically fold into alpha helices or beta-barrels rather than exist as disordered chains?

Solution

A. The two advantages of GFPs over the use of fluorescent-labeled antibodies for studying the location and movement of a protein in cells are

1. They provide a means for identifying the genetically modified cells for physiological studies in unadultrarted living cells thus aviod artefacts arising due to permebilisation and cell fixation.

2. For the expression of other fluoroscent proteins a cofactor is required while GFPs exhibit intrinsic fluoroscence due to cyclisation of three amino acids Ser65-Tyr66-Gly67 and then undergo maturationm process.

B. Empty magnification refers to the magnification of an image beyond its resolution power but without any improvement in the details of the image due to the limitations of the resolving power of the optical system.