Endocrinology Biology 317/319 * * * Final Exam * * * [Date A]

Name _____________________________________

Instructions: 200 pts total, 8 pages; answer all 31 questions. Read all questions carefully and answer accordingly. Good Luck and Have a Great ...!

(150 pts, 1 pt per possible response) Multiple choice. Circle all that apply.

1. To be considered a hormone a compound:

a) must be sensitive to glycolysis
b) must bind to a DNA recognition site
c) must be generated by one cell and act on a second cell
d) must have a defined chemical structure
e) when removed must create a reversible deficiency condition
2. A single cell can:
a) produce multiple hormones
b) respond to protein hormones and steroids simultaneously
c) respond only to limited numbers of identical hormone molecules at the same time
d) both produce and respond to the same hormone
e) only produce or respond to a single hormone at a time
3. Anatomical specializations that help the endocrine system generate its effects include:
a) tight junctions between epithelial or endothelial cells
b) electrical and metabolic coordination of cells by gap junctions
c) the position of the stomach pyloric sphincter
d) the intertwining of the blood vessels supplying the uterus and the ovaries
e) position of the distal convoluted tubule with respect to in-flowing kidney glomerular blood vessels
4. Hormone levels:
a) cannot change if they are to be homeostatic
b) must change to be informative
c) change rapidly due to protein synthesis
d) change rapidly due to protein secretion
e) in the case of steroids may be affected by altered liver function as in alcohol abuse
5. Steroids, vitamin D3 metabolites, thyroid hormones and retinoic acid derivatives all have receptors that:
a) are proteins found in the cell membrane
b) are proteins that bind to DNA in the presence of hormone
c) are unrelated evolutionarily
d) appear to be regulated in part by phosphorylation and heat shock proteins
e) always increase gene transcription in the presence of the appropriate hormone
6. Feedback controls within endocrine systems:
a) that are positive balance hormone levels to maintain homeostasis
b) that are positive usually involve neural afferent signals
c) that are negative ultimately alter the physiology of the system
d) frequently involve the hypothalamus
e) may involve both negative and positive elements at the same time
7. When an organism is exposed to environmental stimuli such as heat, light or imminent danger, such stimuli:
a) may decrease production of a hormone
b) will probably change blood glucose levels
c) may provoke changes in the phosphorylation state of cellular proteins
d) may alter cellular metabolic rate
e) are irrelevant to endocrine control systems
8. Insulin is to glucagon as calcitonin is to:
a) calcium
b) hydroxyapatite
c) parathyroid hormone
d) triglycerides
e) 7-Dehydrocholesterol
9. Insulin is to diabetes mellitus as thyroxine is to:
a) hypothyroidism
b) hyperthyroidism
c) euthyroidism
d) thyrotoxicosis
e) rickets
10. The interdependence of multiple hormonal control systems is illustrated in:
a) lactation
b) thyroid response to thyrotropin
c) blood pressure control
d) parturition
e) puberty
11. An intercellular communication system must involve:
a) a sender
b) a transducer
c) a nondestructive medium
d) a receiver
e) a messenger
12. Oncogenes:
a) were first described by Levi Strauss
b) are mutated or positionally altered genes originally from normal cells that have lost their usual regulated expression
c) are expressed only in retroviruses
d) can be passed from one generation to the next
e) are found only in those cells that produce kinins
13. One possible treatment to help aleviate the effects of incorporation of divalent radioactive cations into tissues is to administer metal chelators such as those used to treat lead and mercury poisoning: EGTA, EDTA, or anti-Lewisite. These seem to function by mobilizing the ions from tissues and maintaining them in solution as metal-chelator complexes, rather than as free (biopotent) ions, so they are filtered into urine and excreted from the body without physiological interference. The difficulties in treatment are often associated with having to bind much of the normally circulating cations in order to effectively transfer cations out of the body. What should the effects of treatment with these chelators be on bone and calcium metabolism?
a) bone organic matrix will be lost
b) osteoclast action should be increased
c) osteoblast action should be increased
d) calcitonin levels will rise
e) parathyroid hormone levels will rise
f) 1,25 - Dihydroxycholecalciferol (Calcitriol) levels will rise
g) absorption of dietary calcium will decline
h) excretion of calcium in urine will increase
i) thyroxine levels will rise
j) vasopressin levels will fall
14. The ovulatory cycle of female mammals:
a) allows fertilization at any time during the cycle
b) absolutely requires estradiol action followed by LH action
c) controls the cycle of the myometrium of the uterus
d) usually results in the shedding of oocytes at the prophase of meiosis II
e) results in the shedding of oocytes that are encased within a glycoprotein complex surrounded by cumulus granulosa cells
f) is paralleled by cyclical changes in endometrial morphology
g) results in most primary oocytes ultimately being shed and potentially fertilized
h) is fully functional from the time of birth
i) is solely controlled by the positive feedback of estradiol onto the hypothalamus
j) is regulated such that after death all follicles become necrotic
15. Hormone receptors:
a) may also have enzymatic activities
b) usually interact allosterically with other proteins to evoke cellular responses
c) may interact allosterically with more than one transducing system
d) can be intracellular or plasma membrane associated
e) are always highly specific for the hormone they are named after
16. Blood pressure control is a coordinated series of events directly involving all the following:
a) baroreceptor regulated release of oxytocin
b) osmoreceptor regulated release of vasopressin
c) atrial naturetic factor mediated inhibition of adrenal glomerulosa steroid production
d) atrial kalemic factor mediated increase in salivary excretion of potassium
e) epinepherine stimulation of peripheral blood vessel constriction
f) angiotensin II production catalyzed by converting enzyme
g) testosterone induced liver metabolism
h) prostaglandin production in the kidney
i) the protein hormone renin
j) aldosterone stimulated sodium reuptake by kidney distal tubules
17. The normal phosphoinositide turnover mechanism directly involves all of the following:
a) methylxanthines
b) GTP-binding proteins
c) ATP
d) phospholipase C
e) protein kinase A (I)
f) protein kinase C
g) cAMP-binding regulatory subunits
h) phosphodiesterase
i) inostitol triphosphate
j) diglycerides
18. Which of the following is directly controlled, at least in part, by hormones?
a) homeostasis
b) intermediary metabolism
c) light perception
d) water and electrolyte balance
e) adaptation to stress
f) growth and development
g) taste
h) circulation
i) digestion and absorption of food
j) reproduction
19. The Science article "Cytokines and Estrogen in Bone: Anti-Osteoporotic Effects," by Mark Horowitz indicated that estrogen supplementation probably acts to inhibit osteoporosis in postmenopausal women by:
a) Decreasing monocyte production of parathyroid hormone
b) Increasing osteoblastic production of IL-6
c) Decreasing osteoblastic production of CSF (Colony Stimulating Factors)
d) Decreasing monocyte production of IL-1
e) Inhibiting the differentiation and activation of osteoclasts
20. A chemical assay measures molecular mass of a hormone while a bioassay:
a) can measure the mass of hormone
b) is more essential for protein and peptide hormones than for steroids
c) determines if a portion of the mass of hormone is biologically inactive
d) is only a qualitative assessment
e) defines the potency of a hormone as information content per unit mass
21. The specificity of hormones is due to:
a) their molecular structure
b) the site of their production
c) the specific binding of hormones to plasma proteins
d) the molecular structure of target cell receptors
e) the timing of their production
22. Which of these groups of hormones are synthesized by proteolysis of proteins?
a) peptides
b) catecholamines
c) steroids
d) thyroid hormones
e) carbohydrates
23. Thyrotropin
a) increases uptake of amino acids by target cells
b) stimulates the synthesis of somatomedins
c) enhances glucose uptake by target cells
d) stimulates target tissue growth
e) blocks thyroglobulin release into serum
24. Peroxisomes are involved directly in:
a) the mechanism whereby target cells extract iodine containing thyroxine
b) the mechanism that concentrates iodine in the thyroid
c) the proteolytic process whereby T3 and T4 are released from thyroglobulin
d) the generation of iodotyrosine residues
e) the generation of triiodotyrosine from thyroxine
25. Which of the following characterizes Type I but not Type II diabetes mellitus?
a) hyperglycemia
b) lack of insulin
c) polyuria and polydipsia
d) successful treatment by dietary control alone
e) occurance prior to 20 years of age
II. (50 pts total) Short answers and problems.

26. Blood glucose balance involves the actions of insulin and a group of other hormones. Which of the hormones listed are most responsible for the following changes? (Answers may be used more than once or not at all.)

___ a) stimulation of glucose production by liver
___ b) stimulation of gluconeogenesis in liver
___ c) stimulation of glycolysis in muscle
___ d) stimulation of breakdown of triglycerides and protein in muscle and fat to spare glucose
___ e) stimulation of water reuptake by the distal tubules of the kidney to provide water for metabolism
___ f) support of insulin actions by generation of certain growth factors
___ g) suppression of both glucagon and insulin in the pancreatic islets
___ h) stimulation of glycogenolysis in liver
___ i) enhanced glycogenolysis, lipolysis, and proteolysis in fat and muscle
___ j) stimulation of movement of glucose transport proteins to target cell surfaces
A. Insulin
B. Chorionic gonadotropin
C. Hepatostatin
D. Glycophorin
E. Epinephrine
F. Somatotropin
G. Adipotropin
H. Glucagon
I. Somatostatin
J. Thyroxine
K. None of the Above

27. Molecular genetics is being used increasingly to describe diseases or medical conditions at the DNA level. Many of these diseases or conditions are expressed as mutations in proteins. It is becoming very clear that endocrine diseases or deficits can derive from mutations in proteins that function at many different cellular or systemic levels.

For the corticotropin (ACTH) system, chose from the accompanying list 15 different proteins (enzymes, hormones, structural proteins, etc.) that, if mutated or defective, could lead directly to a disease characterized by absence of the specific, steroid-dependent effects of ACTH.

Corticotropin receptor
Adenylate cyclase
24 - Hydroxylase
Aldosterone receptor
CRH receptor
Glucocorticoid receptor
Progesterone receptor
CBG (transcortin)
HMG-CoA reductase
Protein kinase A
Protein kinase C
Guanylate cyclase
Phospholipase C
90k (MW) Heat shock protein
C20,22 Lyase
18 - Hydroxylase
3ß - Hydroxysteroid dehydrogenase
17[alpha] - Hydroxylase
[delta]4,5 Isomerase
5[alpha] - Reductase
21 - Hydroxylase
11[beta] - Hydroxylase
LDL receptor
Apoproteins A,B,C or E
C17,20 Lyase
Phosphorylase b

28. The Ka's of hormone-receptor complexes quantify the relative amount of ____________ a hormone molecule is likely to reside on a given receptor molecule. These association constants tend to be very ______________ for most hormonal systems because the hormones circulate at levels in the _______________-molar to ______________-molar range. Moreover, the number of receptor molecules in or on each target cell is ________________.

29. Transplantation of the pituitary under the kidney capsule allows elevation of one pituitary hormone and only temporary suppression of two others. Name them and the primary regulator(s) normally controlling them in the hypothalamus.

a. Elevation __________________________(A)
b. Temporary Suppression _________________________(B) ____________________________(B)
c. Primary regulators for (A) ______________________ and (B) ________________________

30. In an interesting view of history a recent author suggested that many of the societal changes that took place prior to the twentieth century occurred because of problems attributable to mass administration of pharmacologically active compounds produced by organisms that were parasites on food plants or that fed on poorly stored bulk foods such as grain. The argument was made that some of the decline in population growth in Europe during periods of cool, wet climate such as the Middle Ages was probably due to increases in the numbers of individuals experiencing ergotism due to consumption of fungally infected rye. Ergot alkaloids are dopaminergic agonists. Which of the following mechanisms probably accounted for the the effects of these compounds on populations?

a) Ergotism caused suppression in sperm motility in most men.
b) Ergotism increased the spread of venereal diseases like gonorrhea by increasing female libido.
c) Ergotism interfered with thyroid function so everyone experienced the lethargy of hypothyroidism.
d) Ergotism caused increased mortality among nursing infants.
e) Ergotism caused premature menopause in women.
f) Ergotism caused widespread impotence in males by inducing diabetes mellitus and its vascular complications.
g) Ergotism delayed puberty by altering adrenarche.
h) Ergotism suppressed fertility in women by inducing amenorrhea.
i) Ergotism caused increased mortality due to premature parturition.
j) Ergotism caused an decrease in the desire to bathe, so people could not stand to be close enough to have coitus.
31. Why is it not surprising that so many direct intercellular interactions trigger biochemical cascades within cells that are virtually indistinguishable from the events triggered by hormone binding?
a) Because all intercellular interactions are actually mediated by hormones.
b) Because the need for interactions that require minimal initial energy input to generate release of substantial intracellular stores of energy to cause physical movements of the cell or its structures are similar in both circumstances.
c) Because the number of potential forms of cellular response are constrained by the possible molecular composition of the cell membrane.
d) Because evolution has probably adapted one form of cellular response to allow the other form.
e) Because at the cellular and molecular levels quantum physics applies so the potential number of molecular states and cellular modes of response are restricted to a very finite number.