Proteins are large, complex molecules that play many critical roles in the body. Some of the actions of protein in the body are: to activate enzymes, move skeletal muscles, transportation of various important substance through cell membranes, activate communication of various hormones, provide blood clotting, as well as the regulation of fluid balance and pH.
Proteins differ from one another primarily in their sequence of amino acids, which is dictated by the nucleotide sequence of their genes , and which usually results in protein folding into a specific three-dimensional structure that determines its activity.
It’s possible to combine different plant foods in order to create a combination that has all essential aminos – such as eating rice with beans or vegetables with whole grains, for example – but some health experts believe this is not as optimal as eating foods that are complete protein sources.
However, we also want to point out that in some other studies on aging, high protein intake has been shown to have the opposite impact: in these studies, low protein, high carbohydrate diets have slowed down the decline in immune system problems when compared with high protein, low carbohydrate diets.
Another applicable technique is cofractionation in sucrose (or other material) gradients using isopycnic centrifugation 47 While this technique does not prove colocalization of a compartment of known density and the protein of interest, it does increase the likelihood, and is more amenable to large-scale studies.