Biochem Chapter 38 Bone Metabolism and Calcium Homeostasis

What is the majority of all bone protein

Collagen type 1

What is osteoid?

Organic matrix of bone secreted by osteoblast and surrounds osteoblast.

When surrounded osteoblast become osteocyte

Osteoid calcifies to form spicule and then trabeculae

What is osteomalacia?

Increase in nonmineralized osteoid

In childre is called rickets

What do chondroblast make?

What collagen

Cartilage

Type 2 collagen

Osteoblasts are derived from ________

Osteoclasts are derived from ________

mesenchyme

hematopoietic stem cells

RANKL-RANK interaction

What about OPG

RANKL is produced by osteoblasts

RANKL bind to RANK on osteoclast stimulate survival (more resorption)

OPG is produced by osteoblasts and is decoy for RANKL to decrease bone resorption

How is vitamin D made in skin?

UV radiation

Calcidiol and Calcitriol

Calcidiol is storage form of Vitamin D in liver

Calcitriol is potent Vitamin D (increase absorption) in kidney

Osteoblast forms bone on bone surface and once they trap themselves in the _______, they differentiate to osteocytes

lacunae

Chondroblasts vs Chondrocytes

Chondroblasts: Secrete matrix that become cartilage

Chondrocytes: Mature Chondroblasts in lacunae (maintain matrix)

What is dead bone separated from healthy one

Sequestrum