What 2 components are responsible for the hardness and pliability of bones?

Bones are composed of two main components that contribute to their hardness and pliability:

1. Collagen: Collagen is a protein that makes up about one-third of the organic material in bones. It provides flexibility and tensile strength, which allows bones to withstand pulling and bending forces without breaking. Collagen fibers are arranged in a lattice-like structure, providing a flexible and resilient framework for bone tissue.

2. Minerals: Minerals, primarily calcium and phosphorus, make up about two-thirds of the bone's weight and give bones their rigidity and hardness. Calcium phosphate, in the form of hydroxyapatite crystals, is deposited within the collagen matrix, forming a strong mineralized composite. These mineral crystals provide bones with their characteristic strength and resistance to compression.

The combination of collagen and minerals creates a unique material that is both hard and flexible, enabling bones to withstand various mechanical stresses and forces while still providing support and protection for the body's organs.