Biochem 3-2

1.

1 point

Which of the following characterizes nitric oxide (NO)?

diffuses into cells

NO is degraded by a phosphodiesterase

reduces concentration of Ca2+

Viagra can be used to extend the signal

increases concentration of cAMP

2.

1 point

When cAMP bind to the catalytic subunit of PKA, the regulatory subunits dissociate.

True

False

3.

1 point

What is the main difference between plasmalogens and phospholipids?

phospholipids have no cell signaling purpose

plasmalogens have the same fatty acid at C-1 and C-2

plasmalogens have an ether linkage at fatty acid C-1

phospholipids do not have an alcohol group attached

4.

1 point

Histone acetyltransferase (HAT) removes the charge from histones to allow easier access to DNA by transcription factors.

True

False

5.

1 point

What unit from GPCR is Ras (from RTK) similar to?

G-beta

7 transmembrane helicies

G-gamma

adenylate cyclase

G-alpha

6.

1 point

What enzyme is phosphorylated by Raf (from the receptor tyrosine kinase)?

ERK

Ras

Sos

GRB2

MEK

7.

1 point

Which of the following is true of G-protein couple receptors and their signal transduction?

the signal molecule bind to the G-alpha subunit

G(q) stimulates cAMP phosphodiesterase

G-alpha becomes active when GTP is bound

G-alpha dissociates from beta and gamme after GTP is bound

active G-alpha can activate or inhibit adenylate cyclase

8.

1 point

Which of the following would be below normal levels in Hashimoto's thyroiditis

thyrotropin releasing hormone (TRH)

thyroid stimulating hormone (TSH)

T3

T4

9.

1 point

Insulin signaling uses what major class of hormone signaling?

nuclear receptors

GPCR

serine/threonine kinases

intrinsic guanylate cyclase receptors

receptor tyrosine kinases

10.

1 point

Most eicosanoids participate in G-protein coupled reactions.

True

False

11.

1 point

Which of the following is characteristic of Group I signaling molecules?

are mainly G-protein coupled receptors

diffuse through cell membrane

hydrophilic

hydrophobic

receptors are found on cell surface

12.

1 point

Which of the following enzymes is NOT involved in alcohol metabolism?

glycerol kinase

acetaldehyde dehydrogenase

alcohol dehydrogenase

acetyl-CoA synthase

13.

1 point

Which of the following refers most specifically to blood type antigens?

sphingolipids

glycosphingolipids

phosphoacylglycerol

phospholipids

14.

1 point

Which of the following causes irreversible inhibition of PGH2 synthase?

ibuprofen

aspirin

thrombaxanes

glucocoricoids

15.

1 point

Which of the following is true of both cholera toxin and pertussis toxin?

both lead to an increase in cAMP

both prevent GTP from leaving the G-alpha unit of GPCR

both attack the G-alpha(i) family of GPCR

both prevent GTP from binding to the G-alpha unit of GPCR

16.

1 point

Which of the following can lead to acidosis in alcoholics?

accumulation of ketone bodies

accumulation of lactate

accumulation of NAD+

accumulation of pyruvate

17.

1 point

Which of the following is contained within sphingomyelin?

fatty acid

glucose

glycerol

serine

phosphate group

18.

1 point

Which of the following are examples of ligands for serine/threonine kinase?

ANF

BMP

TGF-beta

steroid hormones

cytokines

19.

1 point

Which of the following is a possible product of the phosphotidyl inositol signal cascade?

diacylglycerol (DAG)

IP3

monoacylglycerol

arachidonic acid

20.

1 point

What type of cancer does Tamoxifen and Raloxifene counteract by bind to the receptor?

pancreatic cancer

breast cancer

bone marrow cancer

liver cancer

21.

1 point

Disulfiram increases the toxic effects of alcohol by inhibiting alcohol dehydrogenase.

True

False

22.

1 point

What transcription factor ensures long lasting changes in gene expression from GPCR?

CREB

STAT

JAK

MAPK

23.

1 point

Which of the following (either directly or indirectly) activate PKC?

IP3

DAG

increased Ca2+ levels

cAMP

24.

1 point

What is the major difference between the JAK/STAT pathway and RTK?

the JAK/STAT pathway uses serine/threonine kinases instead of tyrosine kinases

the tyrosine kinase is cytosolic in the JAK/STAT pathway

the JAK/STAT pathway has a phosphotase activity rather than a kinase activity

RTK requires the presence of tyrosine kinase

25.

1 point

Alcohol dehydrogenase determines your alcohol tolerance.

True

False

26.

1 point

Asthma medication inhibit what enzyme that synthesizes leukotrienes?

aromatase

5-lipoxygenase

PGH2 synthase

epoxygenase

27.

1 point

Which of the following is characteristic of nuclear receptors?

does not use G-coupled protein receptors

central DNA binding domain of zinc fingers

group I signaling mechanism

transcription alteration by binding to hormone response elements

28.

1 point

Which of the following eicosanoid do NOT signal via GPCR?

leukotrienes

prostaglandins

15-d-PGJ2

thromboxanes

platelet activating factor

29.

1 point

Respiratory Distress Syndrome is cause by the lungs not producing enough what?

dipalmitoylphosphotidylcholine

triglycerides

lysophospholipids

sphingomyelin

30.

1 point

What enzyme is deficient in Niemann-Pick type A?

phospholipase A2

spingomyelinase

hexosaminidase

lipoprotein lipase

31.

1 point

What structure are most eicosanoids synthesized from?

stearate

arachidonic acid

linoleate

palmitate

32.

1 point

What type of cell signaling would insulin be?

endocrine

paracrine

autocrine

juxtacrine

33.

1 point

Which of the following could cause Cushing disease or Cushing syndrome?

excessive use of corticosteroids

desensitization of the hypothalamus and anterior pituitary to feedback inhibition

hypercortisolemia

desensitization to cortisol by peripheral body cells

34.

1 point

Which of the following diseases is cause by deficient production of gonadotropin releasing hormone?

Kallmann syndrome

Klinefelter syndrome

Cushing syndrome

Turner syndrome

35.

1 point

Which of the following is NOT an eicosanoid?

steroid hormones

thrombaxanes

prostacyclins

leukotrienes

prostaglandin

36.

1 point

Which of the following is NOT a nuclear receptor?

glucocorticoid receptor

thyroid hormone receptor

epidermal growth factor receptor

estrogen receptor

37.

1 point

How would you be able to tell the difference between Graves' disease and hyperthyroidism (the most common form)?

in hyperthyroidism T3 and T4 levels are elevated

in Graves' disease TSH levels would not be elevated

patients would only exhibit weight loss with Graves' disease

in Graves disease T3 and T4 levels are elevated

38.

1 point

Which of the following are examples of how cells terminate signaling?

receptor internalization

phosphatase activity to turn of activated enzymes

degradation of extracellular signal

receptor modifications

degradation of secondary messangers (such as cAMP and CGMP)

39.

1 point

Which of the following would produce a phospho-alcohol and a diacylglyceride?

Phospholipase A1

Phospholipase A2

Phospholipase C

Phospholipase D

40.

1 point

What enzyme is deficient in von Recklinghausen disease where Ras is hyperactive?

Sos

GAP

Raf

GEF

41.

1 point

Increased ceramide release can be used as a signal by cells to induce what?

increase triglyceride synthesis

cell division

apoptosis

increased glucose uptake

42.

1 point

What enzyme is over-activated by enterotoxigenic E. coli (traveler's diarrhea)?

tyrosine kinase

serine/threonine kinase

JAK

guanylate cyclase

adenylate cyclase