In 1988, Richardson and Richardson observed that certain amino acid residues are statically favored as the amino-terminal caps for the alpha helices in 45 globular proteins. Which of the following statement stand correct with stability of helix?

A. The introduction of a negatively charged side chain at the N-cap, which can neutralize the partial dipole created by the unpaired amide protons, has been shown to increase stability

B. In particular, Gly is often observed at the both C-cap position and N-cap positions

C. In particular, Gly is often observed at the C-cap position only

D. In particular, Gly is often observed at the C-cap position, Asn at the N-cap position, Pro at the Ncap+1 and Asp and Glu at N2 and N3

TLS Online TPP Program

#Question id: 23166

#Unit 13. Methods in Biology

To visualize two proteins in fixed Hela cells using an epifluorescence microscope. Below is a list of various fluorophores (dyes) available to see those proteins.

1. FITC

2. GFP

3. Fluorescein

4. Alexa 568

Select the correct combinations of the appropriate dyes that would typically be utilized to observe co-localization in an epifluorescence microscope?

TLS Online TPP Program

#Question id: 23162

#Unit 13. Methods in Biology

Match the fluorescent dyes in column I with emission light in column II

Column I	Column II
1. Texas	a. far red
2. Fluorescein	b. red
3. Rhodamine	c. blue
4. Cy5	d. green

Which of the following option comprises all correct matches?

TLS Online TPP Program

#Question id: 23155

#Unit 13. Methods in Biology

Match the following ions in column I with their relevant dyes column II.

Column I	Column II
1. K+	a. Fura-2
2. Ca2+	b. SNARF-1
3. H+	c. Ion potassium green

Which of the following options is correct?

TLS Online TPP Program

#Question id: 23152

#Unit 13. Methods in Biology

A fluorescent dye SNARF-1 that is sensitive to H+ concentrations can be used to monitor the cytosolic pH of 

1. Alkaline cells

2. Acidic cells 

3. Dead cells

4. Live cells

Which of the following options are incorrect?

TLS Online TPP Program

#Question id: 23151

#Unit 13. Methods in Biology

If the concentration of Ca2+ is high inside the cell and fura-2 dye is used to map the concentration which of the following conditions will prevail?

1. Fluorescence will decrease

2.  Fluorescence will increase

3. Emission of light at higher wavelength

4. Emission of light at lower wavelength

Which of the following options are correct?

TLS Online TPP Program

#Question id: 23148

#Unit 13. Methods in Biology

There are two proteins A and B to be visualized under fluorescence microscopy. Both of them are excited with same wavelength of light but A emits longer wavelength. Hence we can conclude that 

1. A is denser molecule than B

2. B is denser molecule than A

3. A is lighter molecule than B

4. B is lighter molecule than A

Which of the following option is incorrect?