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