Aavwv

mRNA

Protein synthesis on mRNA template

Protein synthesis on mRNA template

Ribosome

Ribosome

Completed Figure 35-9. The expression of genetic inprotein formation in DNA into the form of an mRNA molecule transcript. This is subsequently translated by ribosomes into a specific protein molecule.

In mammalian cells, including cells of humans, the mRNA molecules present in the cytoplasm are not the RNA products immediately synthesized from the DNA template but must be formed by processing from a precursor molecule before entering the cytoplasm. Thus, in mammalian nuclei, the immediate products of gene transcription constitute a fourth class of RNA molecules. These nuclear RNA molecules are very heterogeneous in size and are quite large. The heterogeneous nuclear RNA (hnRNA) molecules may have a molecular weight in excess of 107, whereas the molecular weight of mRNA molecules is generally less than 2 X 106. As discussed in Chapter 37, hnRNA molecules are processed to generate the mRNA molecules which then enter the cytoplasm to serve as templates for protein synthesis.

Diabetes 2

Diabetes 2

Diabetes is a disease that affects the way your body uses food. Normally, your body converts sugars, starches and other foods into a form of sugar called glucose. Your body uses glucose for fuel. The cells receive the glucose through the bloodstream. They then use insulin a hormone made by the pancreas to absorb the glucose, convert it into energy, and either use it or store it for later use. Learn more...

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