What vitamin is essential for changing phydroxyphenylpyruvate into homogentisate?
إجابة
(D)
Niacin
2
Which vitamin is necessary for the conversion of folic acid into folinic acid?
إجابة
(C)
Ascorbic acid
3
What substance can be reduced by ascorbic acid?
إجابة
(C)
2, 6-Dichlorophenol indophenol
4
Which vitamin is typically depleted in sterilized milk?
إجابة
(C)
Vitamin C
5
What condition results from a lack of a specific vitamin?
إجابة
(D)
Vitamin C
6
Both Wernicke's disease and beriberi can be treated with the administration of which vitamin?
إجابة
(B)
Thiamin
7
What is a consequence of a lack of Vitamin B₁?
إجابة
(C)
Beriberi
8
Which vitamin's deficiency leads to elevated levels of pyruvic and lactic acid in the blood?
إجابة
(A)
Thiamin
9
The coenzyme TPP, derived from which vitamin, is crucial for what process?
إجابة
(A)
Oxidative decarboxylation
10
An increase in glucose intake necessitates a greater dietary intake of which vitamin?
إجابة
(D)
Thiamin
11
In an alkaline solution, what substance is used to convert thiamin to thiochrome through oxidation?
إجابة
(B)
Potassium ferricyanide
12
Riboflavin acts as a coenzyme in reactions catalyzed by which of the following enzymes?
إجابة
(B)
Acyl CoA dehydrogenase
13
What is the approximate daily riboflavin intake, in milligrams, recommended for adults?
إجابة
(B)
1.2-1.7
14
Which vitamin deficiency can result in hyperbilirubinemia in newborns undergoing phototherapy?
إجابة
(B)
Riboflavin
15
Which of the following conditions is a consequence of riboflavin deficiency?
إجابة
(A)
Cheilosis
16
What vitamin deficiency is associated with a magenta-colored tongue?
إجابة
(A)
Riboflavin
17
Which vitamin deficiency is linked to corneal vascularization?
إجابة
(B)
B2
18
Which of the following is known as the pellagra-preventing factor?
إجابة
(C)
Niacin
19
Pellagra is a condition that arises from a deficiency of which vitamin?
إجابة
(D)
Niacin
20
Niacin, also known as nicotinic acid, is derived from which of the following?
إجابة
(A)
Pyridine
21
What is the starting material for niacin production within the human body?
إجابة
(A)
Tryptophan
22
Which of the following amino acids is typically lacking in the proteins found in corn?
إجابة
(C)
Tryptophan
23
In what form is niacin typically found in corn?
إجابة
(C)
Niacytin
24
Approximately how much tryptophan is needed to produce 1 mg of niacin in the body?
إجابة
(B)
60 mg of tryptophan
25
In populations that rely heavily on which of the following grains is pellagra most commonly observed?
إجابة
(C)
Maize
26
Which type of enzymes utilize nicotinamide as a coenzyme?
إجابة
(A)
Dehydrogenases
27
What is the recommended daily intake of Vitamin D?
إجابة
(A)
400 I.U.
28
Which vitamin's structural composition lacks a ring structure?
إجابة
(A)
Pantothenic acid
29
Pantothenic acid is a key component in a coenzyme involved in which metabolic process?
إجابة
(C)
Acetylation
30
From which of the following is CoA derived?
إجابة
(D)
Pantothenate
31
What nutritional deficiency is linked to 'burning foot syndrome'?
إجابة
(A)
Pantothenic acid
32
Which biochemical process centrally involves pyridoxal phosphate?
إجابة
(D)
Transamination
33
Which vitamin serves as a coenzyme for transaminase function?
إجابة
(C)
Pyridoxal phosphate
34
Which medication can potentially lead to a vitamin B, deficiency?
إجابة
(A)
Isoniazid
35
Which population group is at higher risk of vitamin B, deficiency?
إجابة
(C)
Alcoholics
36
What vitamin deficiency is assessed using the 'xanthurenic acid index'?
إجابة
(A)
Pyridoxal
37
What vitamin deficiency has been associated with epileptiform convulsions in infants?
إجابة
(C)
B
38
Which type of enzyme utilizes biotin as a coenzyme?
إجابة
(A)
Carboxylase
39
What coenzyme is required for the conversion of pyruvate to oxaloacetate?
إجابة
(D)
Biotin
40
How is biotin attached to enzymes within biotin-containing enzymes?
إجابة
(C)
An amide linkage to an amino group of lysine
41
In a carboxylation reaction where biotin acts as a coenzyme, a CO₂ molecule is captured. To which part of the biotin molecule is the carboxyl group covalently linked?
إجابة
(A)
A nitrogen atom (N₁) within the biotin structure
42
What nutritional deficiency can arise from eating uncooked eggs?
إجابة
(A)
Biotin
43
Which compound or its derivative is essential for transforming acetyl CoA into malonylCoA?
إجابة
(D)
Biotin
44
Which cofactor is necessary for the oxidative decarboxylation of pyruvate?
إجابة
(A)
Lipoate
45
The core structure of B₁₂, known as the corrin ring system, includes which element?
إجابة
(A)
Cobalt
46
In vitamin B₁₂, the central cobalt atom is bound to which type of group?
إجابة
(A)
Cyanide group
47
The complex corrin ring of vitamin B₁₂ is composed of four of what type of rings?
إجابة
(C)
Pyrrole rings
48
What is the empirical formula of cobalamin?
إجابة
(D)
C63H88N14O14P.CO
49
A lack of vitamin B₁₂ can lead to which medical condition?
إجابة
(C)
Pernicious anemia
50
How can a vitamin B₁₂ deficiency be identified through analysis of urine?
