________ form a small group of proteins that bind to GPCRs and compete for binding to those GPCRs with heterotrimeric G proteins.
Arrestins
_____ is formed from the amino acid L-______ in a reaction catalyzed by the enzyme _____.
Nitric oxide, arginine, nitric oxide synthase
The process that blocks active receptors from turning on additional G proteins is called ________.
desensitization
What molecule is responsible for activating Rsk-2?
MAPK
_________ are enzymes that phosphorylate specific tyrosine residues on protein substrates.
Protein-tyrosine kinases
Why do colds cause us to lose some of our appreciation for the taste of food?
The symptoms of colds prevent stimuli from reaching olfactory neurons efficiently, thus dulling the perception of taste.
What group of enzymes phosphorylates most of the carbons on inositol?
phosphoinositide kinases
Accessory proteins that maintain monomeric G proteins in an inactive state by inhibiting GDP-GTP exchange are called:
GDIs
The concentration of calcium ions in the ER lumen, the plant cell vacuole and the extracellular space are on average more than _______ times higher than in the cytosol.
10.000
What does the interaction between arrestin and clathrin promote?
the uptake of phosphorylated GPCRs into the cell by endocytosis
How can one identify oncogenes?
by introducing the DNA suspected of containing the oncogene into cultured cells and looking for altered growth properties
What happens if one cultures cells from a tumor lacking a functional RB gene after reintroducing a wild-type copy of the gene into those cells?
The cancer phenotype disappears.
__________ is new blood vessel formation.
Angiogenesis
What generally happens if cells that have been transformed into cancer cells in culture by carcinogenic chemicals or viruses are introduced into a host animal?
They generally cause tumors in the host animal.
What is the name for tiny regulatory RNAs that negatively regulate the expression of target mRNAs?
microRNAs
A well-known cell-survival pathway involves a kinase called _______ that is activated by the _______, leading to a larger chance that the cell will survive a stimulus that would normally lead to its destruction.
PKB, phosphoinositide PIP3
The fact that tumor cells depend, in many cases, on glycolysis may reflect ________.
the high metabolic requirements of cancer cells and an inadequate blood supply within the tumor
A lack of a functional TP53 gene __________.
causes a cell carrying damaged DNA to fail to be destroyed
and
will allow genetically unstable cells to continue to divide
Which of the following enzymes is known to be expressed at a high level in the cancer cells of patients suffering from acute myeloid leukemia and at low levels in the cancer cells of patients suffering from acute lymphoblastic leukemia?
catalase
Whether a cell lives or dies after a particular event depends to a large degree on ________ between ________ and _________ signals.
the balance, proapoptotic, antiapoptotic
Which of the following features would be a requirement for a receptor that exhibits ligand-mediated dimerization?
The ligand has two binding sites for receptors.
How were nitroglycerine's therapeutic benefits discovered?
the fact that dynamite factory workers with heart conditions had less angina on days that they worked
The _________ pathway of apoptosis is one in which external stimuli activate apoptosis via a signaling pathway.
extrinsic
What kind of enzyme is the RAS gene product, the Ras protein?
a GTPase
Which of the following processes is not regulated by eicosanoids?
neurotransmission
What can cause the stockpile of intracellular calcium ions to be depleted?
periods of repeated cellular responses
In which organism below has calmodulin not been found?
bacteria
In order to begin desensitization, the ________ domain of the activated G protein-coupled receptor is phosphorylated by a specific enzyme called a(n) ________.
cytoplasmic, G protein-coupled receptor kinase
While bound to phosphorylated GPCRs, to what else can arrestins bind?
clathrin molecules in clathrin-coated pits
From what molecule are the steroids derived?
cholesterol
Why do tumor viruses transform normal cells into cancer cells?
They carry genes whose products interfere with the cell's normal growth-regulating activities.
Which of the following is not a mechanism of action for a small-molecule targeted therapy?
Inhibition of estrogen synthesis
___________ of miRNAs ____________.
Expression; has been shown inhibit the expression of human oncogenes, abnormal expression; has been implicated as a causal factor in tumor cell invasiveness and metastasis and, expression; has been shown inhibit the expression of RAS and MYC
Which cells generally lack the ability to divide?
differentiated end products of a tissue
Which type of new screening test will be able to identify cancers based on the presence of specific genes associated with various types of cancer?
genomics
Chronic infection with what stomach-dwelling bacterium has been associated with certain gastric lymphomas?
Helicobacter pylori
Retinoblastoma is inherited as a ____________.
dominant genetic trait
How might blocking angiogenesis have a negative impact as a cancer treatment?
by creating a more O2-deficient environment for the tumor cells, and by driving tumor cells to seek out other sites in the body
For what disease has the human monoclonal antibody Arzerra been approved for treatment?
chronic lymphocytic leukemia
What generally happens if cells that have been transformed into cancer cells in culture by carcinogenic chemicals or viruses are introduced into a host animal?
They generally cause tumors in the host animal.
Which of the following enzymes is known to be expressed at a high level in the cancer cells of patients suffering from acute myeloid leukemia and at low levels in the cancer cells of patients suffering from acute lymphoblastic leukemia?
catalase
What is unusual about the inheritance of retinoblastoma, given that it appears to be inherited as a dominant trait?
Not all children who inherited the RB deletion developed retinoblastoma.
If any of the proteins involved in mismatch repair are damaged, the mutation rate and cancer risk will rise; this is called the ___________.
mutator phenotype
The cancer vaccine DCVax utilizes which type of cells from the patient?
dendritic cells
Which one of the following viruses does not appear to be linked to human cancers?
rhinovirus
Mutant forms of which of the following genes have been associated with melanomas and colorectal cancers, respectively?
BRAF and APC
What part of the cell cycle does the pRB protein help to regulate?
the G1 - S transition
Which of the genes below would be a viral gene?
par
With respect to cancer genetics and the cancer genome, what are passenger genes?
genes that are subject to mutation but have no effect on the phenotype of a cancer cell
What happens quite often to the number of normal receptors in the plasma membranes of malignant cells as compared to normal cells?
Malignant cells usually have a much larger number of plasma membrane receptors than normal cells.