QuestionSBA
QuestionChoice
1-alpha hydroxylase is an enzyme made in the kidneys. It catalyses the hydroxylation of 25-hydroxyvitamin D3 into 1,25-hydroxyvitamin D, which is commonly known as calcitriol.
10003376
a
1-alpha hydroxylase
QuestionChoice
Cytochrome P450 is a family of enzymes involved in the breakdown of proteins, steroids, hormones, and fatty acids. They are made by the liver.
10003380
e
Cytochrome P450
QuestionChoice
Vitamin C ferrireductase is found in enteral cells (gut cells). It works by converting Fe3+ (ferric iron) to Fe2+ (ferrous iron).
10003379
d
Vitamin C ferrireductase
QuestionChoice
Phospholipase A2 plays a role in the synthesis of arachidonic acid from phospholipids in the arachidonic acid pathway. It is a common target for anti-inflammatory drugs such as steroids.
10003378
c
Phospholipase A2
QuestionChoice
Ferrochelatase catalyses the insertion of ferrous iron (Fe2+) into Protoporphyrin, allowing the synthesis of haem.
10003377
b
Ferrochelatase
Concept
Chapter
2693
4153
Renal physiology – Vitamin D activation
Topic
145
Orthopaedics
13222
Vitamin D is important in calcium homeostasis. It increases calcium levels in the blood and can be obtained from several sources including the sun, supplements and Vitamin D-rich foods such as spinach and other green leafy vegetables.

With regards to the metabolism of Vitamin D, what is the enzyme responsible for the formation of 1,25-Hydroxyvitamin D?
a