Final answer:
Globular proteins form as a result of hydrophobic and hydrophilic interactions that drive their folding into functional three-dimensional shapes. Misfolding of these proteins can lead to diseases. Glycine can disrupt alpha helical structures due to its small size and flexibility, which interferes with the necessary hydrogen bonding.
Step-by-step explanation:
Globular proteins arise from the interactions between amino acids within a polypeptide chain. These interactions are driven by the hydrophobic and hydrophilic properties of amino acid side chains.
In an aqueous environment, hydrophobic (water-fearing) side chains tend to cluster together, avoiding water, whereas hydrophilic (water-loving) side chains interact with the surrounding water. This leads to a three-dimensional folding pattern that results in the functional globular shape of proteins.
Changes in the shape of proteins, often referred to as conformational changes, can be detrimental to their function and lead to diseases. A misfolded protein can result from genetic mutations, environmental conditions, or post-translational modifications, and these aberrant proteins can aggregate, forming toxic species that disrupt cellular functions.
Regarding the amino acid glycine, it is known to disrupt the formation of an alpha helical polypeptide structure because of its small size and lack of a bulky side chain. This allows for more flexibility in the protein backbone, which can interrupt the regular hydrogen bonding pattern necessary for the stability of the alpha helix, potentially leading to changes in protein folding and function.