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8

A pre-tRNA is transcribed from tRNA genes in DNA by RNA polymerase III. Processing occurs in the nucleus, where a 5' sequence is cleaved by RNase P, the 3's CCA motif is added, and ~10% of the nucleotides are substituted. The tRNA are transported out via the pore complexes. Aminoacyl-tRNA synthetase enzymes attach amino acids in the cytoplasm in a 2-step ...


5

Okay, so for introduction the 4 levels of protein structure (each level influences the levels after it): primary (1st): the order of amino acids. secondary (2nd): alpha-helicies and beta-sheets tertiary (3rd): complex 3d structure quaternary (4th) : 3rd+ non-protein elements (ions, co-factors etc) and / or multple subunits interact. Not every protein has ...


5

The word complex in your sentence designate a protein complex, also called multiprotein complex. A protein complex is a group of two or more polypeptide chains that bind together to make up a functional unit. A complex can be made up of similar polypeptide chains or totally different polypeptide chains. Proteasome, Metabolon or hemoglobins are examples. ...


5

The stacking gel concentrates proteins loaded into the sample wells so that they are resolved as a unified "line" once they enter the stacking gel. The reason for the lower pH is that this "lower ionic strength implies higher electrical resistance and consequently a higher electric field, provoking the faster movement of the proteins and of every other ...


4

The other major difference between the two is the amount of acrylamide in the upper (stacking) gel - it's generally around 4%, while the lower (resolving) gel can vary from 6 or 8% to 20%, depending on the size of the protein(s) you're looking for. When you load your samples in the wells at the top of the gel, then start the current, not all of the sample ...


4

TL;DR: Chymosin is similar to pepsin and I couldn't find any evidence of functional/expressed chymosin gene in human genome. It seems like a common misconception that chymosin is functional in humans. Already in 1940s it has been shown that rennin (aka chymosin) is absent from "gastric juice" in adult humans. Genetically there is only pseudo-gene for ...


3

From what you say, I can only give a few advices: For the quantification, make sure your sample does not contain any substances which disturb the assay. The Bradford assay is for example sensitive against SDS or DTT. See here for more details. This prevents you from loading a sample without enough protein. Make sure that you really have protein on your ...


2

The tricky part is to define what is the volume of a biomolecule as it is a folded chain full of bumps and holes. Water is all around and in the folded structure and is actually important to keep the conformation of at least some of the proteins/RNA/DNA. At the same time we know that 60% of your body in mass is water. Let's visualize that. Bio molecules ...


1

After I had check so many possibilities I finally resolve the problem. It turns out that ph of the tris 1,5M for gel preparation was too many basic...which explain a smear of the proteins into the gel


1

According to the Molecular Biology of the Cell, (4th Ed), the cell is ~70% water, the remaining 30% of which is composed of macromolecules (proteins, nucleic acids, and carbohydrates). While this is just a single citation, there are lots of other sources in the literature that cite similar values.



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