When the ribosome reaches a stop codon on the mrna, no corresponding trna enters the a site. if the translation reaction were to be experimentally stopped at this point, which of the following sets of structures would you be able to isolate from the cell?

The options are:

A) an assembled ribosome with a polypeptide attached to the tRNA in the P site

B) separated ribosomal subunits, a polypeptide, and free tRNA

C) an assembled ribosome with a separated polypeptide

D) separated ribosomal subunits with a polypeptide attached to the tRNA

E) a cell with fewer ribosomes

The correct answer is A) an assembled ribosome with a polypeptide attached to the tRNA in the P site.

Explanation:

There are three sites in a ribosome E, P, and A. From A site aminoacyl tRNA enters the ribosome. When this tRNA shifts to P site the amino acids which were attached to the tRNA that was at P place shifts to a new tRNA molecule that replaced the old one.

The old deacylated tRNA leaves the mRNA-ribosome complex from E- site. So when translation reaction was to be experimentally stopped and there is no corresponding tRNA enters the A site then only an assembled ribosome with polypeptide chain attached to tRNA in P site can isolate from the cell because no tRNA is present at E and A site.

the oxygenated blood then leaves the lungs through pulmonary veins, which return it to the left heart, completing the pulmonary cycle. this blood then enters the left atrium, which pumps it through the mitral valve into the left ventricle. from the left ventricle, the blood passes through the aortic valve to the aorta.

deoxygenated blood leaves through the right ventricle through the pulmonary artery. from the right atrium, the blood is pumped through the tricuspid valve (or right atrioventricular valve), into the right ventricle.

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consumers: deer, mice, rabbits, chickens, squirrels, horses, worms, cows

predators: eagles, frogs, wolves, owls