Protein or the physical region of the protein that participates in chemical catalysis. In solution proteins also undergo variation in structure through thermal vibration and the collision with other molecules. Proteins can be informally divided into three main classes, which correlate with typical tertiary structures: globular proteins, fibrous proteins, and membrane proteins. Almost all globular proteins are soluble and many are enzymes. Fibrous proteins are often structural, such as collagen, the major component of connective tissue, or keratin, the protein component of hair and nails. Membrane proteins often serve as receptors or provide channels for polar or charged molecules to pass
Whey protein collection of globular proteins isolated from whey. The protein in cow's milk is 20% whey protein and 80% casein protein, whereas the protein in human milk is 60% whey and 40% casein. The protein fraction in whey constitutes approximately 10% of the total dry solids in whey. This protein is typically a mixture of beta-lactoglobulin (~65%), alpha-lactalbumin (~25%), bovine serum albumin (~8%)(see also serum albumin), and immunoglobulins. These are soluble in their native forms, independent of pH. The amino acid cysteine in whey protein is a substrate for the synthesis of glutathione in the body which is a ubiquitous cellular