Author Question: What vitamin is essential for normal synthesis of prothrombin group proteins, thus enabling them to ... (Read 123 times)

khang · **on:** Jun 25, 2018

What vitamin is essential for normal synthesis of prothrombin group proteins, thus enabling them to bind Ca2+?

a. Vitamin K
b. Vitamin B12
c. Vitamin C
d. Vitamin D

Question 2

Absence of D dimers is useful for ruling out:

a. Deep venous thrombosis
b. von Willebrand disease (VWD)
c. Protein C deficiency
d. Factor VII deficiency

asdfghjkl; · **Reply #1 on:** Jun 25, 2018

Answer to Question 1

ANS: A
Vitamin K is necessary for carboxylation of glutamic acid residues on the precursor prothrombin group proteins. This carboxylation results in the ability of these proteins to bind Ca2+.

Answer to Question 2

ANS: A
The D dimer is a specific marker for thrombosis; when the assay is negative, it is useful for ruling out DVT. (A positive result does not rule in DVT because D dimers are increased in many situations.)