Answer:
The miRNAs act as post-transcriptional silencers, as they are similar to specific mRNAs and regulate their stability and translation. They are small endogenous non-coding ribonucleic acid (RNA) molecules, with about 22 nucleotides, which act as regulators of gene expression in plants and animals, at the post-transcriptional level through the cleavage of a target messenger RNA (mRNA) or repression of translation.
In general, most miRNA genes are transcribed by RNA polymerase II in the nucleus in primary miRNAs (pri-miRNAs). Individually, a pri-miRNA can produce a single miRNA or contain groups of two or more miRNAs that are processed from a common primary transcript. These long pri-miRNA are cleaved by a complex comprising the double-stranded RNAse III enzyme (DROSHA) and its essential cofactor, the binding protein DGCR8 (DiGeorge Syndrome Critical Region 8 protein) in mammals. DROSHA contains two domains of RNAse III, each of which cleaves a strand of the RNA resulting in the precursor microRNA (pre-miRNA) with about 70 base pairs, which contains a double-stranded stretch and a single-stranded loop, forming a structure in clamp. The pre-miRNA is exported to the cytoplasm by the protein exportin-5 (XPO-5), where it is cleaved by DICER1, an RNAse III that assesses the 3 'and 5' ends of the pre-miRNA, generating a mature miRNA with about 22 nucleotides. The processing of pre-miRNA by Dicer promotes the unfolding of the RNA duplex in the form of a clamp. The position in the formation of the clamp can also influence the choice of tape.
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Answer:
e. All of the above are False.
Explanation:
A tRNA is a transfer RNA that carries amino acid from the cell pool to the mRNA-ribosome complex. The anticodon sequence of tRNA is complementary to the mRNA codons and bind to the respective amino acids. None of the tRNA has anticodon for stop codons and therefore, as soon as the ribosome reaches stop codon, protein translation terminates.
AUG is the initiation codon for protein synthesis and codes for methionine when present at a site other than the start site. The initiation codon is often preceded by an untranslated sequence, also called leader sequence. The ribosome moves along the mRNA in 5' to 3' direction in a GTP dependent manner to facilitate elongation of the polypeptide chain.
Words can only describe but if you have a model you can show people what is happening rather them just using their imagination
Answer:
He developed the theories of gravitation in 1666, when he was only 23 years old. Some twenty years later, in 1686, he presented his three laws of motion in the "Principia Mathematica Philosophiae Naturalis." The laws are shown above, and the application of these laws to aerodynamics are given on separate slides.
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