Endocrine System
An amino acid-based hormone binds to its receptor. This has the effect of:
Activating an enzyme to produce cAMP
Causing it to diffuse through the cell to trigger a cascade of reactions
Activate a G-protein
Allowing it to move along the membrane
Activate a G-protein
After a hormone binds to its receptor, a G (for guanine) protein is activated as the first effect. The G-protein then moves along the membrane to activate an enzyme that produces, for example, cAMP, which is a “second messenger”.
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Which statement is NOT CORRECT?A. Males and females produce testosterone and estrogen, respectively, in their gonads.
B. Both male and females produce follicle stimulating hormone and luteiniz-ing hormone.
C. Oxytocin is produced and released from the anterior lobe of the pituitary gland.
D. Production of testosterone and estrogen inhibits the release of gonadotrophin- releasing hormone from the hypothalamus.
Which of the following is an amino acid derivative hormone?
A. Epinephrine
B. Tyrosine
C. Testosterone
D. Prostaglandin
Which of the following statements about endocrine hormones is always true?
A. They are secreted by neurones.
B. They are derived from amino acids.
C. They are produced by exocrine glands.
D. They are released into the bloodstream.
Which hormones are produced by the adrenal cortex and contribute to carbohydrate metabolism?
A. Androgens
B. Mineralocorticoids
C. Glucocorticoids
D. Gonadocorticoids
Which of the following is NOT a mechanism of hormone action?
A. A hormone may activate an enzyme.
B. A hormone may bind to a protein to alter the permeability of the plasma membrane.
C. A hormone may bind to troponin to expose the binding site the myosin cross-bridge.
D. A hormone may enter the cell to stimulate cell mitosis.
Which statement below about hormones is true?
A. Hormones are enzymes that catalyse reactions.
B. Hormones are released into the blood circulation.
C. Hormones affect all cells of the body.
D. Hormones are released by neurones at synapses.
Which of the following lists of organs and hormones involved in a control process that releases that hormone is WRONG?
A. Hypothalamus, anterior pituitary, thyroid-stimulating hormone
B. Hypothalamus, posterior pituitary, antidiuretic hormone
C. Hypothalamus, adrenal medulla, epinephrine
D. Thalamus, hypothalamus, oxytocin
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