Tissues with greater protein density have a higher rate of absorption. Which tissue is among those with greater protein density?

• A. Tendon
• B. Fat
• C. Nerve
• D. Skin

Answer: (A)

Tissues with a lot of structural proteins form a dense network that interacts with diffusing substances. Tendon is dominated by collagen, a fibrous protein, arranged in tightly packed bundles, so it has far higher protein density than the other options. Fat is largely lipid with little protein, nerve tissue has proteins but not in such a dense, organized matrix, and skin contains collagen but also many other components that reduce the overall protein density compared with tendon. Because its matrix is so protein-rich, tendon best fits the scenario of higher protein density among these tissues, which is why it’s the best choice for illustrating a higher rate of absorption in this context.