蛋白素

• 疋(foot; leg (sound similar to 'đản'))PHONETIC
• 虫(insect; reptile)RADICAL

An egg is what reptiles lay, with a round shape like a foot.

• 白(white; light; bright)ASSOCIATIVE

The sun radiating bright rays suggests the pristine white color.

• 糸(silk thread; filament)RADICAL
• 龶(coarse undyed thread bundle; top part of thread)ASSOCIATIVE

Raw silk that hasn't been dyed suggests the meaning of pure, simple, and basic.