Collagen & Bones Flashcards
Vitamin C
Hydroxylation (of proline & lysine during collagen synthesis)
In collagen synthesis, what part happens outside the cell
lysyl oxidase (LOX) for cross-linking collagen
Lysyl oxidase- ________ is needed (cofactor)
Cu
What is the 3rd AA sequence in collagen?
Glycine-proline-lysine (Glycine-Proline-X or Glycine-X-Hydroxyproline)
What amino acids other than glycine is found in collagen?
Proline & Lysine
What is lysine involved in?
Crosslinking
What is present in collagen, that isn’t in elastin?
Hydroxylysine
What is found only in collagen & reticular fibers?
tropocollagen, also has hydroxyproline & hydroxylysine
Elastin has what?
glycine, alanine, proline, & hydroxyproline, also has tropoelastin
what is not needed for synthesis for collagen?
Vitamin K or Folic Acid
what is responsible for calcium regulation?
parathyroid hormone (increase serum calcium)
Main role of calcitonin?
bone reabsorption
osteoclasts
monocytes
what is no in periosteum?
Osteocytes
what cytokines are found in Osteoclastic Bone?
IL-1, IL-6, PGE2, TNF-alpha, MMPs
What are housed in Howship’s Lacunae?
Osteoclasts
what is howship’s lacuna?
groove/cavity usually containing osteoclasts that occurs in bone which is undergoing reabsorption
What is the Trabecular bone?
the 1st resorbed by osteoclasts, creating a shallow resorption put (Howship’s lacuna), then osteoclast deposit compact bone in the pit
what is the Endosteum?
thin layer of CT that line the surface of bony tissue that form the medullary cavity of long bones
What type of bone do you see after 2-3 years at the site of injury?
Compact bone
Which of the following is not found in compact bone?
fibroblast
What is the chemical formula of the most common salt found in the bone?
HA, Ca10(PO4)6(OH)2
Vitamin D deficiency
kids: Rickets, adult: Osteomalacia
Vitamin D 25 hydroxycholecalciferal gets converted to 1, 25 dihydroxycalciferol where?
Kidney
Where do you get Vitamin D from?
Skin, liver, kidney
