Cunningham - Tumor Physiology lecture Flashcards
________ carries the genetic code (codons complementary to that of DNA genes) from the nucleus to the cytoplasm for controlling the type of protein formed.
A. Precursor messenger RNA B. Small nuclear RNA C. Messenger RNA D. Transfer RNA E. Ribosomal RNA
C. Messenger RNA
Which of the following is found in higher concentrations inside the cell versus in the extracellular fluid? A. Glucose B. Mg C. Ca D. HCO3
B. Mg
PIP2 is hydrolyzed into 2 second messengers by phospholipase C. Which of these second messengers then mobilizes intracellular Ca2+? A. DAG B. IP3 C. cAMP D. cGMP E. Calmodulin
Correct answer: B.
Ref: Cunningham, pg. 29
In the MAP Kinase pathway, Ras in its GTP-bound form sends a stimulatory signal to \_\_\_, which is a MAP kinase, kinase, kinase. A. Raf B. Mek C. Erk D. Fak E. Src
Correct answer: A.
Ref: Cunningham, p 41-42
Which of the following plays the most significant regulatory role in the restriction point decision of the cell cycle?
a) Cyclin A or B
b) Cyclin dependent kinase 2
c) P53
d) Retinoblastoma
Correct Answer: D
Ref: Cunningham, p 44
Explanation: CDK4/6 and cyclin D phosphorylates RB which releases it from the E2F transcription factor
What is the role of Bcl-2 in the cell?
a) Inhibits Bax in the intrinsic apoptosis pathway
b) Inhibits p53 in the extrinsic apoptosis pathway
c) Activates caspases in the extrinsic apoptosis pathway
d) Activates RB in the intrinsic pathway
Correct Answer: A
Ref: Cunningham, p 47
Explanation: p53 signals cell stress and activates the intrinsic pathway. Bcl-2 is not involved in the extrinsic pathway. RB is not involved in apoptosis.
Which cellular receptor does not utilize a second messenger?
A. G Protein Coupled Receptors
B. Tyrosine Kinase Receptors
C. All cellular receptor families utilize second messenger systems
D. Nuclear receptors
Correct answer: B
Ref: Cunningham p 23, 31, 39
What is the function of Calmodulin?
A. Facilitates release of Ca2+ from the sarcoplasmic reticulum
B. Binds Ca2+ in the cytosol
C. Serves as a second messenger for the GPCR
D. Serves as a second messenger for the Tyrosine Kinase Receptor
Correct answer: B
Ref: Cunningham p 25
Which one of the following enzymes hydrolyzes 3’,5’-adenosine monophosphate (cAMP) to 5’AMP?
a. Phosphodiesterase
b. Protein kinase A
c. Adenylyl cyclase
d. Myosin kinase
Correct answer: A
Ref: Cunningham p 27
Phosphatidylinositol 4,5-bisphosphate (PIP2) is hydrolyzed to which combination of the following second messengers?
a. Calcium and 3’,5’-adenosine monophosphate (cAMP)
b. Diacylglycerol (DAG) and inositol 1,4,5-triphosphate (IP3)
c. Inositol 1,4,5-triphosphate (IP3) and calcium
d. Diacylglycerol (DAG) and 3’,5’-adenosine monophosphate (cAMP)
Correct answer: B
Ref: Cunningham p 24
Which ion is an essential component of the DNA-binding domain of nuclear receptors?
a. magnesium
b. zinc
c. copper
d. iron
Answer: B
Reference: Cunningham, p 30
Phosphorylation reactions in cell receptors of cell growth pathways primarily involve which amino acid residue?
a. threonine
b. serine
c. cysteine
d. tyrosine
Answer: D
Reference: Cunningham, p. 39
Which 3 kinases are mitogen activated protein kinases or MAP kinases? A. Raf, Mek and Erk B. GDP, Mek and Erk C. Ras, Raf and Erk D. p53, Ras Raf
Correct Answer: A
Ref: Cunningham p. 41
What phase of the cell cycle is driven by Cyclin D/CDK4, 6? A. M B. S C. G1 D. G0
Correct answer: C
Ref. Cunningham p 38
What protein binds cytoplasmic Ca2+ to activate cellular processes?
a. Cyclic AMP
b. Phosphatidylinositol
c. Calmodulin
d. Cyclin
Correct answer: C
Ref: Cunningham 25
How does the MAP Kinase pathway ultimately affect cell cycle?
a. Regulation of transcription factors via upregulation of cyclin-CDK
b. Production of ATP for cellular processes
c. Inhibition of mitotic spindle formation to slow down mitosis
d. Phosphorylation of DNA polymerase
Correct answer: A
Ref: Cunningham p 41
Cyclic AMP is generated through GPCR linked activation of
a) Phosphodiesterase
b) Adenylyl cyclase
c) Phospholipase
d) GTPase
Correct Answer: B
Ref: Cunningham p 25
DNA is duplicated in which phase of the mammalian cell cycle?
a) M phase
b) G1 phase
c) G2 phase
d) S phase
Correct Answer: D
Ref: Cunningham p 36
Which of the following describes the elements that interact to produce cyclic AMP?
a. Calcium ions, calmodulin, and adenylyl cyclase
b. A cytosolic receptor, a G protein, and adenylyl cyclase
c. A membrane receptor, a G protein, and adenylyl cyclase
d. A membrane receptor, a G protein, and protein kinase A
Correct Answer : C
Ref: Cunningham p 25
Following cell adhesion to an extracellular matrix, what are two important intermediates in the activation of the MAP kinase pathway to stimulate the cell cycle?
a. Src and Fak, both protein tyrosine kinases
b. Src, a protein tyrosine kinase, and Ras, a small G protein
c. Src, an adhesion receptor, and Fak, a protein tyrosine kinase
d. Src, a receptor tyrosine kinase, and Fak, a protein tyrosine kinase
Correct Answer : A
Ref: Cunningham p 43
Elimination of cyclic AMP (cAMP) is regulated by which enzyme that hydrolyzes the cAMP to “normal” AMP?
a. Adenylyl cyclase
b. Phosphodiesterase
c. Phospholipase C
d. Diacylglycerol
Correct Answer: B.
Reference: Cunningham p 27-28; Figure 1-18
Angiogenesis is needed for tumor progression. Which growth factor plays an important role in angiogenesis and can increase the permeability of existing vessels?
a. Epidermal growth factor
b. Thrombospondin-1
c. Platelet derived growth factor
d. Vascular endothelial growth factor
Correct Answer: D.
Reference: Cunningham p 53
There are numerous g-coupled protein receptors in the body that have a set site of action. These receptors can often be manipulated with various medications. Which of the following best describes these g-coupled proteins and their ability to effect blood pressure, and what medications can we utilize clinically to affect blood pressure?
A. Prostaglandin receptors only affect the reproductive cycle and have no effect on the vasculature.
B. Alpha adrenergic receptors regulate vascular tone and can be directly influenced by losartan to alter blood pressure.
C. Calcitonin receptors help to regulate bone absorption and calcium metabolism, subsequently allowing for manipulation of blood pressure through its direct activation.
D. Muscarinic stimulation with medications such as atropine can improve blood pressure through its effects on the heart.
Correct Answer: D
Ref: Cunningham p 21
It is important to differentiate between the processes of apoptosis and necrosis, as there are many sequelae to an “ungentlemanly” destruction of a cell. What are the main differences between these two processes and their effects on surrounding tissue?
A. Although both processes begin with the formation of blebs in the cells, the nucleus and mitochondrion stay intact with necrosis, and phagocytes ingest the formed membrane bound bodies in apoptosis to reduce area inflammation.
B. Only apoptosis begins with the formation of blebs in the cells; the nucleus and mitochondrion stay intact with necrosis, and phagocytes ingest the formed membrane bound bodies in apoptosis to reduce area inflammation.
C. Although both processes begin with the formation of blebs in the cells, mitochondrion break up with necrosis, and phagocytes ingest the formed membrane bound bodies in apoptosis to reduce area inflammation.
D. Although both processes begin with the formation of blebs in the cells, the nucleus breaks up with necrosis, and phagocytes ingest the formed membrane bound bodies in apoptosis to reduce area inflammation.
Correct Answer: C
Ref: Cunningham p 46
Which protein has been noted to leak from the outer membrane of mitochondria in the process of stimulation of apoptosis?
a. Cytochrome c
b. p53
c. Bcl-2
d. Ras
Correct Answer: A
Ref: Cunningham p 48
This prevents the loss of coding DNA
a. Telomeres
b. Telomerase
c. Caspase
d. Centromere
Correct Answer: A
Ref: Cunningham p 49
Which of the following correctly matches proteins with their function in the G1 checkpoint (restriction point)?
a. p21 increases the activity of CyclinD-CDK4, which phosphorylates key proteins needed to progress to S phase
b. Rb binds to E2F, inactivating it and preventing transcription of genes necessary for DNA replication
c. p53 increases the transcription of p21 and decreases the transcription of Rb
d. p53 upregulates the production of Cyclin E, which binds to CDK2 and phosphorylates key proteins needed to initiate DNA replication
Correct Answer: B
Ref: Cunningham p 44-45, Fig 2.8 and 2.9
Which of the following is true regarding second messenger signaling using PIP2?
a. PIP2 is a rare membrane phospholipid that is broken down into two signaling subunits by phospholipase C
b. IP3 is a lipid soluble break down product of PIP2 that can activate proteins and channels attached to the phospholipid bilayer
c. DAG is a water soluble break down product of PIP2 that can activate calcium channels or initiate transcription
d. Phosphodiesterase inactivates DAG within the cytosol rapidly, so elevated levels are transient
Correct Answer: A
Ref: Cunningham p 29
The binding of an opioid to its cell surface G-Coupled-Protein Receptor (GPCR) will result in the ______________ of this __________________ “secondary messenger”.
a. Increase, cAMP
b. Decrease, cAMP
c. Increase, Ca
d. Decrease, Ca
e. Increase, DAG
Correct answer: B
Ref: Cunningham p 27
The DNA binding domain of nuclear receptors, is part of the protein shaped into “fingers” by a ___________________ ion.
a. Copper
b. Gold
c. Calcium
d. Zinc
e. Lipid
Correct answer: D
Ref: Cunningham p 30
