Which of the following does not contain a hydrophobic structure?

Glycogen is a polysaccharide composed of glucose units, which are polyhydroxy aldehydes or ketones [t3][t8]. These molecules contain multiple hydroxyl (-OH) groups that are polar and capable of forming hydrogen bonds with water, making them inherently hydrophilic rather than hydrophobic [t3]. In contrast, the other options contain significant hydrophobic structures. Nylon is a synthetic polyamide with long hydrocarbon chains between amide groups. Natural rubber consists of cis-polyisoprene, a nonpolar hydrocarbon polymer. Linseed oil is a triglyceride containing long-chain fatty acids [t2][t5]. Fatty acids are characterized by long hydrocarbon 'tails' that are nonpolar and hydrophobic [t1][t4][t7]. While lipids like linseed oil are 'water-fearing' due to these hydrocarbon chains [t5][t6], glycogen's structure is dominated by polar functional groups that interact favorably with water [t3].

Sources

1. [1] https://sist.sathyabama.ac.in/sist_coursematerial/uploads/SBC1101.pdf
2. [2] https://www.ncbi.nlm.nih.gov/books/NBK525952/
3. [3] https://www.khanacademy.org/science/biology/macromolecules/lipids/a/lipids