Quick Biochemistry - Vitamins (Section 4)

1
What is needed for the creation of methionine from homocysteine?
Answer
(C)
Methylcobalamin
2
Which substance is essential for the body to absorb Vitamin B12?
Answer
(D)
Both hydrochloric acid and intrinsic factor
3
What type of molecule is intrinsic factor?
Answer
(B)
Glycoprotein
4
What is the chemical nature of Castle's Extrinsic Factor?
Answer
(D)
Cyanocobalamin
5
Where in the body is Vitamin B12 stored?
Answer
(C)
Stored in liver
6
What protein carries Vitamin B₁₂ in the bloodstream?
Answer
(D)
Transcobalamin II
7
Which organisms produce Vitamin B12?
Answer
(A)
Bacteria only
8
What can cause a Vitamin B12 deficiency?
Answer
(D)
All of these
9
How can a Vitamin B12 deficiency be identified?
Answer
(D)
Schilling test
10
After a gastrectomy, how long does it typically take for megaloblastic anemia to develop?
Answer
(D)
Years
11
What substance is NOT synthesized with the aid of ascorbic acid?
Answer
(C)
Bile pigments
12
Which mineral's intestinal absorption is improved by vitamin C?
Answer
(C)
Iron
13
The activity of vitamin C is found in which of the following?
Answer
(C)
L-Ascorbic acid
14
For which of the following processes is vitamin C necessary?
Answer
(A)
Bile acids from cholesterol
15
Which condition is caused by a lack of vitamin C?
Answer
(D)
Scurvy
16
How can a vitamin C deficiency be detected at an early stage?
Answer
(C)
Ascorbic acid saturation test
17
What is the approximate daily requirement of vitamin C for adults?
Answer
(C)
70 mg
18
Which vitamin from the provided choices requires the largest daily intake?
Answer
(D)
Ascorbic acid
19
A deficiency of which of the following does NOT lead to anemia?
Answer
(A)
Thiamin
20
Which vitamin can be produced within the human body?
Answer
(B)
Niacin
21
A laboratory test for identifying a lack of vitamin B₁₂ involves measuring the amount of which substance excreted in urine?
Answer
(C)
Methylmalonic acid
22
What structural component is found within the vitamin A molecule?
Answer
(B)
B-lonone ring
23
Which substance serves as the starting material for the creation of Vitamin A?
Answer
(D)
All of these
24
How many molecules of vitamin A can be produced from a single molecule of a specific precursor?
Answer
(B)
B-Carotene
25
What factor is necessary for the process that converts ẞ-carotene into retinal?
Answer
(D)
All of these
26
The process of converting retinal into ritonal requires which of the following?
Answer
(B)
NADPH
27
Retinal is transformed into retinoic acid through the action of what agent?
Answer
(D)
Spontaneously
28
Following absorption in the intestine, where is vitamin A initially released into?
Answer
(B)
Lacteals
29
In which part of the body is vitamin A primarily stored?
Answer
(A)
Liver
30
Rhodopsin is composed of opsin and which other component?
Answer
(A)
11-cis-retinal
31
Upon exposure to light in rod cells, what transformation occurs involving retinal isomers?
Answer
(D)
11-cis-retinal transforms into all-trans-retinal
32
The conversion of all-trans-retinal to all-trans-retinol necessitates which of the following cofactors?
Answer
(D)
NADPH
33
Where can retinol isomerase be found within the body?
Answer
(B)
Liver
34
Which compound exhibits antioxidant properties?
Answer
(A)
B-Carotene
35
The activity equivalent to one international unit (IU) of vitamin A is present in which quantity?
Answer
(B)
0.3 µg of retinol
36
What is a typical daily intake of vitamin A recommended for an adult male, expressed in IU?
Answer
(C)
5,000 IU
37
Vitamin B6 encompasses which of the following compounds?
Answer
(D)
All of the above
38
A preliminary consequence of vitamin A deficiency is
Answer
(C)
An extended period of dark adaptation
39
What condition is defined as nyctalopia?
Answer
(D)
Inability to see in low-light conditions
40
Rod cells contain a protein embedded in the cell membrane that is known as:
Answer
(C)
Rhodopsin
41
Which of the following substances are considered precursors to Vitamin A?
Answer
(C)
Carotenes
42
What function is associated with Retinoic acid?
Answer
(B)
Support growth and differentiation
43
What is the non-protein component of the light-sensitive pigments found in cone cells?
Answer
(C)
11-cis-retinal
44
In what biological process does Retinoic acid play a role?
Answer
(D)
Glycoproteins
45
What is the nature of Transducin?
Answer
(D)
All of these
46
Which of the following is classified as a precursor to Vitamin D3?
Answer
(C)
7-Dehydrocholesterol
47
In which organisms is Ergosterol primarily found?
Answer
(B)
Plants
48
What substance serves as a provitamin D produced within the human body?
Answer
(B)
7-Dehydrocholesterol
49
In what organ does the process of 25-hydroxylation of vitamin D primarily take place?
Answer
(B)
Liver
50
Which of the following substances promotes increased reabsorption of calcium in the kidney tubules?
Answer
(C)
Calcitriol