Download paracrine NO, neurotransmitters, … endocrine any hormone any

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Cell & Molecular Biology
BIOL 405
Test 4
December 5, 2014
True/False (1 point each). Circle the correct response.
(1)
(2)
(3)
(4)
(5)
(6)
(7)
(8)
(9)
(10)
T
T
T
T
T
T
T
T
T
T
F
F
F
F
F
F
F
F
F
F
(11)
(12)
(13)
(14)
(15)
(16)
(17)
(18)
(19)
(20)
(21)
(22)
(23)
(24)
(25)
(26)
(27)
(28)
(29)
(30)
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
All of the proteins of the electron transport chain are coded for by mitochondrial DNA.
All of the mitochondrial tRNAs are coded for by mitochondrial DNA.
All of the mitochondrial rRNAs are coded for by mitochondrial DNA.
Mitochondrial DNA is circular.
The genetic code of the mitochondria is the same as the eukaryotic nuclear genetic code.
The citric acid cycle (Kreb’s cycle) occurs in the intermembrane space of the mitochondria.
The proteins of the electron transport chain are imbedded in the inner mitochondrial membrane.
The enzyme ATP synthase is imbedded in the inner mitochondrial membrane.
The energy that drives ATP synthase is a hydrogen-ion-concentration gradient.
In the electron transport chain, as electrons move from carrier to carrier, hydrogens ions are pumped from the
intermembrane space into the matrix.
According to the endosymbiosis theory, mitochondria were once mutualistic bacteria in primitive eukaryotic cells.
Peptide signal molecules bind to cell surface receptors.
Exosomes are membrane enclosed packets of protein or RNA that are released from cells.
Nitric oxide (NO) is a paracrine signal molecule.
Nitric oxide (NO) is synthesized in smooth muscle cells of arterioles.
Active MPF is cyclin B bound to active (properly phosphorylated) Cdk1.
Active MPF can phosphorylate certain proteins.
A tumor originates from a single cell.
Sarcomas are cancers that arise from epithelial cells.
The normal p53 gene product, when active, can induce apoptosis.
The normal p53 gene product, when active, can halt the cell cycle.
The normal p53 gene product, when active, can induce DNA repair.
Li-Fraumeni syndrome involves a mutation of a ras gene.
In normal cells, DNA damage causes MDM2 to bind to p53 thereby inactivating and degrading p53.
DNA damage results in the phosphorylation of p53 and MDM2.
p53 is an example of a tumor suppressor gene.
p53 mutations are rare in cancers.
The ras family of genes is an example of a family of tumor suppressor genes.
When the ras protein is bound to GTP, cell division is turned on.
The ras mutation that is found in cancer results in the ras protein always being bound to GDP.
Fill in the Blank (2 points each). Fill in the blank with whatever is described by the phrase.
(1)_____________________________
paracrine
(7)_____________________________
adenylyl cyclase
The type of cell signaling in which the signal molecule moves to the target cell by
diffusion.
An example of a signal molecule (or class of signal molecules) described in problem
1.
The type of cell signaling in which the signal molecule moves to the target cell by
way of the circulatory system.
An example of a signal molecule (or class of signal molecules) described in problem
3.
An example of a signal molecule (or class of signal molecules) that crosses the
membrane of the target cell and binds to a receptor in the cytoplasm.
Aspirin, Celebrex, and Vioxx are all examples of this type of anti-inflammatory drug
that block cyclooxygenase.
The enzyme that converts ATP into cAMP.
(8)_____________________________
G protein (α chain, active G protein)
The molecule that binds to this enzyme (problem 7) and thereby activates it.
(2)_____________________________
NO, neurotransmitters, …
(3)_____________________________
endocrine
(4)_____________________________
any hormone
(5)_____________________________
any steroid
(6)_____________________________
NSAIDs
G-protein-coupled receptor
(9)_____________________________
The seven-pass membrane protein to which a signal molecule binds, thereby
activating and releasing the active problem-8 molecule.
cAMP
(10)_____________________________
The “second messenger” molecule in this system (problems 7-9).
carcinoma
(11)_____________________________
Classified by cell-type origin, this is the most common type of cancer.
1
contact inhibition
(12)_____________________________
Cancer cells lose the ability to stop migrating and dividing when they come in
contact with other cells—that is, they lose this characteristic of normal dividing cells.
metastasis
(13)_____________________________
The term for the characteristic of advanced cancers in which they becomes invasive,
partially due to the production of proteases that digest collagen and other proteins.
(14)_____________________________
Ames test
The test for mutagenesis in which a chemical to be tested is first exposed to a liver
extract then this product is used in a bacterial mutagenesis assay.
(15)_____________________________
ATM
The protein kinase that phosphorylates MDM2.
Discussion (40 points). Answer one of these two questions.
1. Describe in detail the mechanism of the regulation of the G2/M checkpoint involving MPF. Include at least one of
MPF's roles in initiating mitosis.
2. Describe the action of the ras family of genes in regulating the cell cycle in a normal cell. Tells what goes wrong
when a ras gene is mutated in a cancer cell.
2