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