Rho protein, that is necessary for transcription termination, is a _______

Homotetramer

Heterotetramer

Heterohexamer

Homohexamer

Rho is a 46KDa hexameric protein with 6 identical subunits. Thus, it is a holohexamer. A four subunit protein with all identical subunit would be a holotetramer, not identical subunit would be heterotetramer respectively.

Rho-dependent and rho-independent transcription termination mechanisms operate in prokaryotes. Rho independent termination mechanism involves

Binding of the rho protein upstream of the termination element

No protein factors and only RNA secondary structure and run of 'U's

Presence of UGA or UAA stop codons

Binding of accessory factors at termination signal

Phytase, an enzyme produced by Aspergillus niger can be adsorbed on microcrystalline cellulose powder (MCCP). The adsorption follows a Langmuir isotherm and the maximum concentration of the protein that can be obtained on the adsorbent is 70 mg cm^-1. At a concentration of 50 mg L^-1 of protein in the solution, the concentration of protein on the adsorbent reaches 35 mg cm^-1. It is desired to recover 90% of the protein from 1.5 liter of the cell free culture filtrate containing 220 mg L^-1 protein by addition of MCCP to the solution. The concentration of the protein adsorbed on the solid at equilibrium will be:

21.4 mg cm-3

214 mg cm-3

2.14 mg cm-3

None of the above

The rho protein can even bind within operons to terminate transcription.

True

False

Directions : In each of the following questions a statement is given, followed by two conclusions. Give answer :

Statements : About 50 per cent of the animal by-products - hair, skin, horns etc. is edible protein. American chemists have developed a method of isolating 45 per cent of this protein. They used an enzyme developed in Japan to break down soya protein.

Conclusions :
I. Americans have not been able to develop enzymes.
II. Animal by-products protein has the same composition as soya protein.

Only conclusion I follows

Only conclusion II follows

Either I or II follows

Neither I nor II follows

Both I and II follow

Rho shows base preference although it doesn’t have any concensus cis binding sequence. Which region will be expected to bind Rho better?

G and C rich region

A and T rich region

Region rich in C and poor in G

Region rich in A and poor in T

As temperature increases, the electrical resistivities of pure metals $$\left( {\rho m} \right)$$ and intrinsic semiconductors $$\left( {\rho s} \right)$$ vary as follows

Both $$\rho m$$ and $$\rho s$$ increase

Both $$\rho m$$ and $$\rho s$$ decrease

$$\rho m$$ increases and $$\rho s$$ decreases

$$\rho m$$ decreases and $$\rho s$$ increases

The moment of inertia of a uniform sphere of radius, r about an axis passing through its centre is given by $$\frac{2}{5}\left( {\frac{{4\pi }}{3}{r^5}\rho } \right).$$ A rigid sphere of uniform mass density $$\rho $$ and radius R has two smaller spheres of radii $$\frac{R}{2}$$ hollowed out of it as shown in the figure given below.

The moment of inertia of the resulting body about Y-axis is

$$\frac{{\pi \rho {R^5}}}{4}$$

$$\frac{{5\pi \rho {R^5}}}{{12}}$$

$$\frac{{7\pi \rho {R^5}}}{{12}}$$

$$\frac{{3\pi \rho {R^5}}}{4}$$

An insulating sphere of radius a carries a charge density $$\rho \left( {\overrightarrow {\bf{r}} } \right) = {\rho _0}\left( {{a^2} - {r^2}} \right)\cos \theta ;\,r

d-1

d-2

d-3

d-4

At time t = 0, a charge distribution $$\rho \left( {\overrightarrow {\bf{r}} ,\,0} \right)$$ exists within an ideal homogeneous conductor of permittivity $$\varepsilon $$ and conductivity $$\sigma $$. At a later time $$\rho \left( {\overrightarrow {\bf{r}} ,\,t} \right)$$ is given by

$$\rho \left( {\overrightarrow {\bf{r}} ,\,t} \right) = \rho \left( {\overrightarrow {\bf{r}} ,\,0} \right)\exp \left( { - \frac{{\sigma t}}{\varepsilon }} \right)$$

$$\rho \left( {\overrightarrow {\bf{r}} ,\,t} \right) = \frac{{\rho \left( {\overrightarrow {\bf{r}} ,\,0} \right)}}{{1 + {{\left( {\frac{{\sigma t}}{\varepsilon }} \right)}^2}}}$$

$$\rho \left( {\overrightarrow {\bf{r}} ,\,t} \right) = \rho \left( {\overrightarrow {\bf{r}} ,\,0} \right)\exp \left$$

$$\rho \left( {\overrightarrow {\bf{r}} ,\,t} \right) = \rho \left( {\overrightarrow {\bf{r}} ,\,0} \right)\exp \frac{\varepsilon }{{\sigma t}}\sin \left( {\frac{{\sigma t}}{\varepsilon }} \right)$$

The resonance widths $$\Gamma $$ of $$\rho ,\,\omega $$ and $$\phi $$ particle resonances satisfy the relation $${\Gamma _\rho } > {\Gamma _\omega } > {\Gamma _\phi }$$ . Their lifetimes r satisfy the relation

$${\tau _\rho } > {\tau _\omega } > {\tau _\phi }$$

$${\tau _\rho }

$${\tau _\rho } {\tau _\phi }$$

$${\tau _\rho } > {\tau _\omega }