Protein folding is the physical process by which a protein chain acquires its native 3-dimensional structure, a confirmation that is usually biologically functional, in an expeditious and reproducible manner. It is the physical process by which a polypeptide folds into its characteristic and functional three-dimensional structure from random coil. Each protein exists as an unfolded polypeptide or random coil when translated from a sequence of mRNA to a linear chain of amino acids. This polypeptide lacks any stable (long-lasting) three-dimensional structure (the left-hand side of the first figure). As the polypeptide chain is being synthesized by the ribosome, the linear chain begins to fold into its three-dimensional structure. Folding begins to occur even during translation of the polypeptide chain. Amino acids interact with each other to produce a well-defined three-dimensional structure, the folded protein (the right-hand side of the figure), known as the native state<span>.</span>
35 parts per thousand
Sea water. Seawater is water from a sea or ocean. On average, seawater in the world's oceans has a salinity of approximately 3.5%, or 35 parts per thousand. This means that for every 1 litre (1000 mL) of seawater there are 35 grams of salts (mostly, but not entirely, sodium chloride) dissolved in it.
Answer:
B Physical separation of populations prevents interbreeding and mixing of gene pools.
Explanation:
Geographic isolation means two populations are unable to reproduce with one another. This means that over time, the variation in the gene pool will be different for one group compared to the other, and the species will genetically diverge from one another. resulting in speciation.
The
plants that produce a seed without a protective cover are known as Gymnosperms.
<span>Gymnosperms<span> have no fruits
(protective cover), and they have unenclosed or “naked” seeds on the surface of
scales or leaves. Their seeds are often called cones. Another difference
from Angiosperms (with enclosed seed) is that they don’t have </span>cotyledons and that their endosperm is haploid</span>