Collagen & Bones

Question 1

Vitamin C

Answer 1

Hydroxylation (of proline & lysine during collagen synthesis)

Question 2

In collagen synthesis, what part happens outside the cell

Answer 2

lysyl oxidase (LOX) for cross-linking collagen

Question 3

Lysyl oxidase- ________ is needed (cofactor)

Answer 3

Cu

Question 4

What is the 3rd AA sequence in collagen?

Answer 4

Glycine-proline-lysine (Glycine-Proline-X or Glycine-X-Hydroxyproline)

Question 5

What amino acids other than glycine is found in collagen?

Answer 5

Proline & Lysine

Question 6

What is lysine involved in?

Answer 6

Crosslinking

Question 7

What is present in collagen, that isn’t in elastin?

Answer 7

Hydroxylysine

Question 8

What is found only in collagen & reticular fibers?

Answer 8

tropocollagen, also has hydroxyproline & hydroxylysine

Question 9

Elastin has what?

Answer 9

glycine, alanine, proline, & hydroxyproline, also has tropoelastin

Question 10

what is not needed for synthesis for collagen?

Answer 10

Vitamin K or Folic Acid

Question 11

what is responsible for calcium regulation?

Answer 11

parathyroid hormone (increase serum calcium)

Question 12

Main role of calcitonin?

Answer 12

bone reabsorption

Question 13

osteoclasts

Answer 13

monocytes

Question 14

what is no in periosteum?

Answer 14

Osteocytes

Question 15

what cytokines are found in Osteoclastic Bone?

Answer 15

IL-1, IL-6, PGE2, TNF-alpha, MMPs

Question 16

What are housed in Howship’s Lacunae?

Answer 16

Osteoclasts

Question 17

what is howship’s lacuna?

Answer 17

groove/cavity usually containing osteoclasts that occurs in bone which is undergoing reabsorption

Question 18

What is the Trabecular bone?

Answer 18

the 1st resorbed by osteoclasts, creating a shallow resorption put (Howship’s lacuna), then osteoclast deposit compact bone in the pit

Question 19

what is the Endosteum?

Answer 19

thin layer of CT that line the surface of bony tissue that form the medullary cavity of long bones

Question 20

What type of bone do you see after 2-3 years at the site of injury?

Answer 20

Compact bone

Question 21

Which of the following is not found in compact bone?

Answer 21

fibroblast

Question 22

What is the chemical formula of the most common salt found in the bone?

Answer 22

HA, Ca10(PO4)6(OH)2

Question 23

Vitamin D deficiency

Answer 23

kids: Rickets, adult: Osteomalacia

Question 24

Vitamin D 25 hydroxycholecalciferal gets converted to 1, 25 dihydroxycalciferol where?

Answer 24

Kidney

Question 25

Where do you get Vitamin D from?

Answer 25

Skin, liver, kidney