There are slight differences in the meanings of these terms, but they are often used interchangeably. 1  Independent Variable: It implies causality: the independent variable affects the dependent variable. 2  Used predominantly in ANOVA, but often in regression as well. 3  It can be either continuous or categorical.
Protein Quality. Collagen is not a complete protein because it is lacking in the amino acid tryptophan. A Protein Digestibility Corrected Amino Acid Score (PDCAA) of a complete protein is 1.0.ollagen is a protein found in the muscle and connective tissue of animals. Hydrolyzed collagen protein supplements are typically made from the bones and skin of cows, horses or pigs.
25-27. 1  Protein makes up around 20% of the body's mass, and collagen makes up around 30% of the protein in the human body. 2  There are at least 16 types of collagen, but 80-90% of the collagen in the body consists of types I, II, and III.