What substance is typically found in higher than normal amounts in the urine of individuals with pheochromocytoma?
پاسخ دهید
(C)
Vinylmandelic acid
2
In the process of creating epinephrine, which enzyme does the drug disulfiram (used to treat alcohol abuse) block?
پاسخ دهید
(B)
Dopamine β-hydroxylase
3
Which enzyme is essential for the creation of both Catecholamine and serotonin?
پاسخ دهید
(B)
N-methyl transferase
4
In what tissues does epinephrine trigger the breakdown of glycogen?
پاسخ دهید
(C)
Liver and muscle
5
What is a likely physiological response to consuming a strong cup of coffee?
پاسخ دهید
(C)
Enhance the effect of epinephrine
6
Through which process is epinephrine created from norepinephrine?
پاسخ دهید
(D)
N-methylation
7
A negative result on a 5 HIAA test could be expected if the patient is taking which medication?
پاسخ دهید
(C)
Phenothiazone
8
The presence of a significant quantity of 5-HIAA in urine often points to what medical condition?
پاسخ دهید
(C)
Metastasis of carcinoma of liver
9
What is considered a normal concentration range for triiodothyronine (T3) in serum?
پاسخ دهید
(B)
0.7-2.0 ng/ml
10
What is a typical range for the concentration of thyroxine (T₄) in serum?
پاسخ دهید
(B)
5.5-13.5 µg/100 ml
11
Overproduction of thyroid hormones leads to which condition?
پاسخ دهید
(A)
Hyperthyroidism
12
A deficiency of free T₃ and T₄ leads to
پاسخ دهید
(B)
Mysoedema
13
In the context of primary hypothyroidism, what is the most valuable measurement to assess?
پاسخ دهید
(D)
Autoantibodies
14
If iodine levels are adequate, what is the approximate T₃ to T₄ ratio in thyroglobulin?
پاسخ دهید
(C)
1:7
15
Which substance interferes with the thyroid gland's ability to absorb iodide?
پاسخ دهید
(A)
Thiocynate
16
Which component is found within the Thyroperoxidase enzyme?
پاسخ دهید
(A)
Heme
17
The Thyroperoxidase enzyme uses hydrogen peroxide for oxidation. How is the H₂O₂ generated?
پاسخ دهید
(D)
NADPH dependent enzyme
18
TSH is composed of two subunits. The α-subunits of TSH, LH, and FSH share similarities. Therefore, the specificity must come from the β subunit, containing how many amino acids?
پاسخ دهید
(B)
112
19
TSH stimulates the production of
پاسخ دهید
(A)
Thyroxine
20
Thyroid hormones are created by adding iodine to which amino acid?
پاسخ دهید
(D)
Tyrosine
21
Approximately how many tyrosine residues are found in each thyroglobulin molecule?
پاسخ دهید
(C)
115
22
What is the approximate percentage of inactive precursors (monoidotyrosine and diiodotyrosine) within thyroglobulin?
پاسخ دهید
(D)
70
23
How many amino acids are typically present in parathormone?
پاسخ دهید
(B)
84
24
Which amino acid sequence is crucial for the biological activity of parathormone?
پاسخ دهید
(B)
1-34
25
What is one effect of PTH?
پاسخ دهید
(A)
Reduces the renal clearance or excretion of calcium
26
How many amino acids are in the peptide hormone calcitonin?
پاسخ دهید
(C)
32
27
What effect does calcitonin generally produce?
پاسخ دهید
(A)
Calcinuria and phosphaturia
28
A key feature of hyperparathyroidism is often
پاسخ دهید
(D)
High serum calcium and low serum phosphate
29
Under what condition is parathyroid hormone typically released?
پاسخ دهید
(C)
Is secreted when Ca++ is too low
30
What hormone is produced by the 8-Cells of the islets of Langerhans in the pancreas?
پاسخ دهید
(C)
Somatostatin
31
What do the B-cells in the pancreatic islets of Langerhans produce?
پاسخ دهید
(A)
Insulin
32
Which tissue does insulin primarily act upon?
پاسخ دهید
(D)
Liver
33
Insulin is composed of two chains. What are the approximate lengths of the A and B chains in terms of amino acids?
پاسخ دهید
(B)
21 and 30
34
In the A chain of the insulin molecule, which amino acid is found at the beginning of the chain?
پاسخ دهید
(A)
Glycine
35
At the end of the A chain in the insulin molecule, which amino acid is located?
پاسخ دهید
(A)
Asparagine
36
What is the first amino acid in the B chain of the insulin molecule?
پاسخ دهید
(C)
Phenylalanine
37
At the end of the B chain in the insulin molecule, which amino acid is present?
پاسخ دهید
(A)
Threonine
38
How many connections, formed by sulfur atoms, exist between the insulin chains?
پاسخ دهید
(B)
2
39
Within a single chain of the insulin molecule, how many connections are formed by sulfur atoms?
پاسخ دهید
(A)
1
40
What element is necessary for insulin to aggregate into larger structures?
پاسخ دهید
(D)
Zinc
41
Approximately how many amino acids are present in pre-pro insulin?
پاسخ دهید
(C)
109
42
How many amino acids are typically found in proinsulin?
پاسخ دهید
(B)
86 amino acids
43
In a healthy adult male, what is the approximate daily insulin secretion?
پاسخ دهید
(D)
50 units
44
What is the approximate insulin content of the pancreas?
پاسخ دهید
(D)
200-250 units
45
What is the approximate half-life of insulin?
پاسخ دهید
(A)
< 3-5 minutes
46
Which metabolic process is stimulated by insulin?
پاسخ دهید
(B)
Hepatic glycogenesis
47
What effect does insulin have on lipid metabolism?
پاسخ دهید
(B)
It decreases lipolysis and increases triglyceride synthesis
48
Insulin enhances the function of which enzyme?
پاسخ دهید
(A)
Pyruvate kinase
49
Which enzyme's activity is reduced by insulin?
پاسخ دهید
(A)
CAMP dependent protein kinase
50
On which chromosome's short arm is the human insulin gene located?
