CBE3

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the activation of a src-type protein

1. dephosphorylation of tyrosine residue 2. binding of activating ligand 3. phosphorylation of the catalytic loop

co-translational transport

1. translation of the proteins is arrested as SRP binds 2. Translation resumes when SRP dissociates 3. First hydrophobic AAs act as start transfer signal 4. translator opens and co-translational transport begins 5. after translation is complete, signal peptidase cleaves 6. ER chaperons (BIP) assit in folding of soluble proteins in the ER lumen 7. properly folded proteins are recognized by cargo receptors on budding transport vesicles 8. ONLY PROPERLY FOLDED PROTEINS GET OUT

What is the refractive index of water?

1.33

What is the refractive index of glass?

1.51

39) In a Lineweaver-Burk plot of the dependence of enzyme velocity on substrate concentration, what is the value of the function at X=0 (i.e., the Y-intercept)? a) Vmax b) 1/Vmax c) -1/Vmax d) 1/Km e) -1/Km

1/Vmax

In a Lineweaver-Burk plot of the dependence of enzyme velocity on substrate concentration, what is the value of the function at X=0 (i.e., the Y-intercept)?

1/Vmax

Approximately how may origins of replication are present in the human genome?

10000

Which of the following isotopes was used by Meselson and Stahl to determine the general mechanism of DNA replication?

15N

how many ATPs hydrolyzed per cycle for ABC pump

During transport of calcium ions by the calcium ATPase, which event happens first?

2 Ca2+ ions are reversibly bound to the alpha subunit

which of the following best describes the orientation of a protein in the er membrane that contains an n-terminal er signal sequence and 2 internal hydrophobic domains a. 3 transmembrane alpha helices with n-terminal in the er lumen b. 3 transmembrane alpha helices with n-terminal in the cytosol c. 2 transmembrane alpha helices with n-terminal in the er lumen d. 2 transmembrane alpha helices with c- terminal in the cytosol e. 2 transmembrane alpha helices with n-terminal and c-terminal on opposite sides of er membrane

2 transmembrane alpha helices with n-terminal in the er lumen

During transport through the V-type ATP-dependent proton pump, how many protons are transported per ATP hydrolyzed?

4 protons pumped per ATP hydrolyzed

What is the largest molecule that can pass through the nuclear pore complex without a nuclear transport receptor?

5 kD

How many protein molecules are incorporated into a clathrin triskelion complex?

) During the IRE1 Unfolded Protein Response, the ribonuclease domain on the cytosolic side of the activated IRE1 receptor excises an intron from a pre-mRNA molecule in the cytosol. The resultant mRNA molecule encodes which of the following? a) A transcription factor b) An SRP protein c) A chaperone protein d) An enzyme e) None of the above

) Lysozyme is an antimicrobial enzyme found in saliva. Which of the following statements about lysozyme is FALSE? a) It hydrolyses proteins b) It binds to 6 sugar residues of the substrate c) It employs coordinated acid base catalysis d) Binding of the substrate results in distortion of the "D" ring e) All of the above are TRUE about the enzyme, lysozyme

At the plasma membrane, which of the following phospholipids is found exclusively on the intracellular [SHOULD HAVE SAID "extracellular"] leaflet? a) glycolipids b) phosphatidylethanolamine c) sphingomyelin d) phosphatidylcholine e) none of the above are exclusively found on the extracellular leaflet

Complete the following sentence "During clathrin-coated vesicle formation, adaptin protein 2 (AP2) complexes are activated by specific ..." a) Phosphoinositides b) Glycolipids c) Sphingolipids d) Rab proteins e) SNARE proteins

During insulin-mediated upregulation of glucose transporters on the plasma membrane, glucose uniporters are delivered to the plasma membrane in vesicles derived from which of the following compartments? a) Recycling endosomes d) Vesicular-tubular clusters b) Multivesicular bodies e) None of the above c) Trans-Golgi network

How does the Akt kinase promote cell survival? a) by phosphorylating and inactivating the BAD protein b) by phosphorylating and activating the BAD protein c) by dephosphorylating and inactivating the BAD protein d) by phosphorylating and activating the Bcl2 protein e) by dephosphorylating and activating the Bcl2 protein

How is phosphatidylserine different from all other phospholipids? a) it is negatively charged at neutral pH b) it is positively charged at neutral pH c) it always contains unsaturated fatty acid tails d) it never contains unsaturated fatty acid tails e) none of the above

Is the following sentence TRUE or FALSE? "Immediately after release of coated vesicles from the source membrane, the coat proteins dissociate." a) The sentence is TRUE b) The sentence is FALSE

Is the following statement TRUE or FALSE? "Cytosolic domains of plasma membrane proteins remain in the cytosol throughout transport through the Golgi." a) the above statement is TRUE b) the above statement is FALSE

Is the following statement TRUE or FALSE? "In some cells, activation of phospholipase C-beta causes waves of Ca2+ release to spread along the endoplasmic reticulum." a) the above statement is TRUE b) the above statement is FALSE

Is the following statement True or False? "Only the extracellular domains of membrane glycoproteins can be glycosylated." a) The statement is True b) The statement is False

Prior to synaptic vesicle fusion, where would you be most likely to find the calcium sensor, synaptotagmin? a) On the synaptic vesicle b) On the cytosolic leaflet of the presynaptic membrane c) On the extracellular leaflet of the presynaptic membrane d) In the synaptic cleft e) On the postsynaptic membrane

The alpha helix is stabilized by which of the following interactions? a) hydrogen bonds between elements of the peptide backbone b) van der Waals attractions between amino acid side chains c) hydrogen bonds between amino acid side chains d) van der Waals attractions between elements of the peptide backbone e) none of the above

The incorporation of a small aperture ("pinhole") near the detector that limits the transmission of out-of-focus light emitted from the specimen is an important feature of which of the following optical techniques? a) confocal microscopy b) phase contrast microscopy c) differential interference contrast microscopy d) electron microscopy e) none of the above

Which of the following amino acid sequences would most likely result in sorting of the protein to the ER?

-Ile-Val-Leu-Leu-Leu-Ala-Leu-Val-Gly-Gly-

When the cyclic AMP-dependent protein kinase (PKA) enters the nucleus, it phosphorylates which of the following transcription factors? a) Cyclic AMP response element binding (CREB) protein b) CREB binding protein (CBP) c) CREB protein kinase (CPK) d) CREB protein kinase kinase (CPK2) e) All of the above

Which feature of the cyclin dependent kinase (Cdk) complex determines the substrate specificity of the kinase? a) the cyclin subunit b) the phosphorylation state of the kinase c) the phosphorylation state of the cyclin d) the availability of ATP e) all of the above determine the substrate specificity of the Cdk complex

Which of the following describes an agent that mimics the effect of ligand by binding to its cognate receptor? a) Agonist b) Antagonist c) Protagonist d) Co-tagonist e) Drug

Which of the following is TRUE regarding most kinesin motor proteins? a) they hydrolyze ATP and move toward the plus (+) end of the microtubule b) they hydrolyze ATP and move toward the minus (-) end of the microtubule c) they hydrolyze ATP and move toward the plus (+) end of the intermediate filament d) they hydrolyze GTP and move toward the plus (+) end of the microtubule e) they hydrolyze GTP and move toward the minus (-) end of the microtubule

Which of the following is one way in which a misfolded protein might be recognized by the protein surveillance machinery of the cell? a) exposed non-polar amino acid side chains b) exposed polar amino acid side chains c) too many amino acids d) too many beta sheets e) too many alpha helices

Which of the following protein complexes can grow new actin filaments at a 70 degree angle from an existing actin filament? a) ARP complexes b) formin dimers c) G1S-cdk complexes d) gamma tubulin ring complexes e) none of the above

Which of the following proteins transports sodium ions against their concentration gradient? a) sodium-potassium ATPase b) sodium-calcium antiporter c) sodium-glucose symporter d) voltage-gated sodium channels e) all of the above transport sodium ions against their concentration gradients

Which of the following sorting signals marks a soluble protein for transport to the nucleus? a) - PPKKKRKL- b) - KDEL-CO2H c) H2N-MLAIVLAIV- d) -SKL-CO2H e) None of the above

Which of the following species was chosen as a model organism for genetic analysis due, in part, to unusually large "polytene" chromosomes? a) Drosophila melanogaster b) Mus musculus c) Caenorhabditis elegans d) Arabidopsis thaliana e) None of the above

Which of the following substrates is phosphorylated by the PI3 kinase? a) phosphatidylinositol 4,5-bisphosphate b) phosphatidylinositol 3,4-bisphosphate c) phosphatidylinositol 3,5-bisphosphate d) phosphatidylinositol 3,4,5-trisphosphate e) none of the above

The Get3 ATPase facilitates the post-translational insertion of certain proteins into the ER membrane. Which is a common feature of proteins that rely on the Get3 ATPase for insertion into the ER membrane? -A single transmembrane domain at the N-terminus -A single transmembrane domain at the C terminus -An intramembrane beta-barrel domain -A kinase domain -A PH domain

A single transmembrane domain at the C-terminus

During the IRE1 Unfolded Protein Response, the ribonuclease domain on the cytosol side of the activated IRE1 receptor excises an intron from a pre-mRNA molecule in the cytosol. The result mRNA molecule encodes for what? -A transport factor -An SRP protein -A chaperone protein -An enzyme

A transport factor

Which of the following amino acid sequences is MOST LIKELY to form an coiled-coil dimer?

-L-A-S-T-A-N-M-L-R-E-Q-V-A-Q-L-

Retention in lumen of ER

-Lys-Asp-Glu-Leu-COOH KDEL

Prior to synaptic vesicle fusion, where would you be most likely to find the calcium sensor, synaptotagmin? -on the synaptc vesicle -on the cytosolic leaflet of the presynaptic membrane -on the extracellular leaflet of the presynaptic membrane -in the synaptic cleft -on the postsynaptic membrane

-On the synaptic vesicle

Which of the following amino acid sequences would most likely result in sorting of the protein to the nucleus?

-Pro-Pro-Lys-Lys-Lys-Arg-Lys-Val-Gly-Gly-

Which of the following signal sequences identifies a protein for nuclear import?

-Pro-Pro-Lys-Lys-Lys-Arg-Val-

During kinesin movement along a microtubule, which event causes the neck linker to "zipper onto the head domain" (i.e., the "Power Stroke") A. dissociation of Pi B. exchange of GDP for GTP C. exchange of ADP for ATP D. hydrolysis of GTP E. hydrolysis of ATP

C. exchange of ADP for ATP

Which of the following is not a serine-threonine kinase? A. protein kinase A (PKA) B. Wee1 kinase C. janus kinase 1 (JAK1) D. calcium-calmodulin (CAM) kinase 1 E. all are serine-threonine kinases

C. janus kinase 1 (JAK1)

Which of the following statements is FALSE regarding microtubules? A. microtubules grow fastest from the plus (+) end B. microtubules are composed of 13 "protofilaments" C. microtubules undergo "catastrophe", during which, protofilaments fray at the minus (-) end D. microtubules are often stabilized by plus (+) end capping proteins E. all of the above are TRUE regarding microtubules

C. microtubules undergo "catastrophe", during which, protofilaments fray at the minus (-) end

Cyclin B (M-cyclin) levels rise throughout S-phase to peak early in G2-phase. However, M-phase does not begin until after G2-phase. Which of the following enzymes prevents premature entry into M-phase? A. cdc25 B. cdk1 C. wee1 D. CAK E. cdc6

C. wee1

5) Which of the following microscopic techniques supports three dimensional reconstruction from optical sections obtained from a fluorescent specimen? a) scanning electron microscopy b) transmission electron microscopy c) confocal laser scanning microscopy d) phase contrast microscopy e) differential interference contrast microscopy

CONFOCAL

In the Golgi complex, ER resident proteins are returned to the ER membrane in.... -Clathrin-coated vesicles -COP1 vesicles -COP2 vesicles -COP3 vesicles -ESCRT vesicles

COP1 vesicles

Occupied KDEL receptors are loaded into which of the following vesicles

COP1 vesicles

Proteins expressing a C-terminal KDEL sequence are returned to the ER in which of the following?

COP1 vesicles

Sustained activation of protein kinase A often results in gene transcription. Which of the following transcription factors is a target of protein kinase A?

CREB protein

After release of the myosin head from an actin filament, which of the following events "cocks" the myosin head into the active conformation.

ATP hydrolysis

During solute transport by an ABC translocator, which event occurs immediately after ATP binding?

ATP hydrolysis

What is the energy source that drives chromosomal segregation during anaphase B?

ATP hydrolysis

How is vesicular fusion powered?

ATP hydrolysis drives the dissociation of SNARE complexes

Which describes an agent that mimics the effect of ligand by binding to its cognate receptor? -agonist -antagonist -protagonist -co-tagonist -drug

Agonist

Which of the following describes a molecule the mimics the effect of a natural ligand by binding to its cognate receptors?

Agonist

Growth factors signal through which of the following kinases?

Akt kinase

Some of the effects of growth factors are mediated through which of the following kinases?

Akt kinase

The PI3 kinase signaling pathway results in the activation of which of the following protein kinases?

Akt kinase

Some of the effects of growth factors are mediated through which of the following kinases?

Akt kinases

Complete the following sentence. "In the Golgi complex, ER resident proteins are returned to the ER membrane in ..." a) Clathrin-coated vesicles b) COP1 vesicles c) COP2 vesicles d) COP3 vesicles e) ESCRT vesicles

During LDL-receptor mediated endocytosis, clathrin-formed vesicles containing the LDL particle-receptor complexes fuse with sorting endosomes. What happens to the LDL receptors? a) they accumulate in the cytosol b) they are returned to the plasma membrane c) they are sent to the Golgi complex for repair d) they are degraded in lysosomes e) depends on the pattern of glycolysis

During dynamic instability of microtubules, when does the "catastrophic" shortening of microtubules occur? a) when GTP levels are exhausted b) when the microtubule loses its "GTP cap" c) when ATP levels are exhausted d) when the ATP-bound form of G-actin falls below the critical concentration e) when microtubules contact the plasma membrane

During nuclear import, what happens IMMEDIATELY AFTER the binding of RAN-GTP to the nuclear import receptor (NIR)? a) Binding of a cargo protein to the NIR b) Dissociation of a cargo protein from the NIR c) Transport of the NIR-RAN-GTP complex out of the nucleus d) Transport of the NIR-RAN-GTP complex into the nucleus e) Hydrolysis of RAN-GTP to RAN-GDP

GTP exchange on the alpha subunit of a trimeric G-protein is facilitated by binding to which of the following? a) A receptor b) An occupied receptor c) An effector protein d) Beta-gamma complex e) None of the above

How is sphingomyelin different from membrane phospholipids like phosphatidylcholine? a) sphingomyelin is not a phospholipid b) sphingomyelin is not a phosphoglyceride c) sphingomyelin is not amphipathic d) sphingomyelin does not diffuse in the lipid bilayer e) sphingomyelin is only found in myelin

In epithelial cells, how is glucose transported across the apical membrane? a) glucose uniporter b) sodium-glucose symporter c) sodium-glucose antiporter d) ATP driven pump e) none of the above

Prior to vesicle formation, how are adaptins recruited to the appropriate membrane. a) by the amount of phosphatidylserine on the membrane b) by specific phosphoinositides on the cytosolic surfacec) by the pH of the compartment d) by the assembly of cargo receptors e) none of the above

The Get3 ATPase facilitates the post-translational insertion of certain proteins into the ER membrane. Which of the following is the common feature of proteins that rely on the Get3 ATPase for insertion into the ER membrane? a) A single transmembrane domain at the N-terminus b) A single transmembrane domain at the C-terminus c) An intramembrane beta-barrel domain d) A kinase domain e) A Pleckstrin Homology (PH) domain

The effect of pertussis toxin treatment on trimeric G-protein signaling is due to which of the following covalent modifications? a) ubiquitination of the alpha subunit b) ADP ribosylation of the alpha subunit c) phosphorylation of the alpha subunit d) phosphorylation of the beta-gamma complex e) dephosphorylation of the beta-gamma complex

The spatial resolution of optical microscopy is primarily a function of which of the following? a) the magnification of the microscope b) the wavelength of the light c) the quality of the glass d) the thickness of the specimen e) none of the above

What is the function of the centriole? a) it is required for the production of microtubules b) it is required for production of cilia c) it is required for the production of the spindle complex d) it is required chromosomal segregation e) it has no known function

Which of following modifications would result in increased membrane fluidity? a) increased cholesterol content b) increased amount of unsaturation of fatty acid tails c) increased chain length of the fatty acid tails d) increased sphingomyelin e) all of the above

Which of the following best describes the orientation within the ER membrane of a protein with an N-terminal ER sorting sequence, and three internal runs of 8 or more non-polar amino acids? a) a protein with three transmembrane alpha helices and the N-terminus in the in the cytosol. b) a protein with three transmembrane alpha helices and the C-terminus in the cytosol c) a protein with three transmembrane alpha helices and both the N-terminus and the C-terminus in the same compartment d) a protein with four transmembrane alpha helices and the N-terminus in the ER lumen e) a protein with four transmembrane alpha helices and the C-terminus in the ER lumen

Which of the following is NOT a structure comprised mostly of actin filaments? a) stress fiber b) primary cilium c) lamellipodium d) contractile ring e) microvilli

Which of the following statements regarding HSP70-type molecular chaperones is TRUE? a) ATP hydrolysis results in the binding of chaperone proteins to polar amino acids on the target protein. b) ATP exchange results in the dissociation of chaperone proteins from hydrophobic amino acids on the target protein. c) GTP hydrolysis results in the binding of chaperone proteins to polar amino acids on the target protein. d) GTP exchange results in the dissociation of chaperone proteins from hydrophobic amino acids on the target protein. e) None of the above statements are true.

ou have isolated a temperature sensitive yeast mutant. When maintained at the restrictive temperature, all of the yeast cells are arrested at the Metaphase-Anaphase (M-A) checkpoint due to a loss-of-function mutation of a single gene. Which of the following proteins / protein complexes is most likely responsible for the observed phenotype (i.e., arrest at M-A checkpoint)? a) P53 b) APC c) ARP d) Cyclin D e) Cyclin E

Which of the following events "cocks" the neck linker on myosin II motor proteins? A. dissociation of the ADP from the motor head B. ATP hydrolysis C. binding of ATP to the motor head D. binding of the motor head to an actin filament E. dissociation of inorganic phosphate from the motor head

B. ATP hydrolysis

Activation of the unfolded protein responses via the IRE1 mechanism results in the accumulation in the ER lumen of which of the following proteins?

BIP

Which of the following proteins is/are an ABC transporter(s)?

Bacterial permeases Cystic fibrosis transmembrane conductance regulator Multidrug resistance proteins

Which of the following are the essential characteristics of all living cells?

Bound by a lipid-rich plasma membrane Contains nucleic acid that encodes at least one copy of the genome Capable of autonomous replication Capable of protein synthesis

) During transport through the V-type ATP-dependent proton pump, how many protons are transported per ATP hydrolyzed? a) 1 proton pumped per ATP hydrolyzed b) 2 protons pumped per ATP hydrolyzed c) 4 protons pumped per ATP hydrolyzed d) 6 protons pumped per ATP hydrolyzed e) 8 protons pumped per ATP hydrolyzed

1) How is the asymmetrical distribution of phospholipids across the plasma membrane created? a) it occurs spontaneously b) different phospholipids are synthesized on each side of the ER membrane and inserted into the lipid bilayer c) ABC transporters called flippases move them between the cytosolic and luminal leaflets of the ER membrane d) extracellular proteins restrict certain phospholipids to the one side of the membrane e) none of the above

During kinesin movement along a microtubule, which event causes the neck linker to "zipper onto the head domain" (i.e., the "Power Stroke") a) hydrolysis of ATP b) exchange of ADP for ATP c) dissociation of Pi d) hydrolysis of GTP e) exchange of GDP for GTP

During receptor-mediated endocytosis, clathrin-coated vesicles sort directly to which of the following compartments? a) cis-Golgi network b) trans-Golgi network c) Early endosomes d) Late endosomes e) Lysosomes

During signaling through a trimeric G-protein, how is the action of the beta-gamma complex terminated? a) GTP hydrolysis b) ATP hydrolysis c) Binding to the GDP-bound form of the alpha subunit d) Binding to the GTP-bound form of the alpha subunit e) Binding to the effector protein

During the formation of clathrin-coated vesicles, a heximeric protein complex of clathrin proteins binds to adaptin molecules to form the clathrin cage. What is the name of this protein complex? a) Triclathrin b) Triskittles c) Triskelions d) Triscallions e) Triguessin

During the transport cycle of the calcium ATPase, which of the following events causes the conformation change that enables transport of 2 calcium ions out of the cytosol? a) phosphorylation of a glutamate residue b) dephosphorylation of a glutamate residue c) phosphorylation of an aspartate residue d) dephosphorylation of an aspartate residue e) GTP hydrolysis

During ubiquitin-mediated proteolysis, which subunit of the ubiquitin ligase complex binds to the target protein? a) E1 b) E2 c) E3 d) E4 e) none of the above

How might the Golgi complex monitor the "progress" of post-translational protein processing? a) by a program of N-terminal proteolysis b) by a pattern of lysine ubiquination c) by modifications of the N-oligosaccharide d) by changes in protein conformation e) by none of the above

Phospholipase C-beta activation leads to the production of (at least) two signaling molecules; inositol 1,4,5-trisphosphate (IP3) and diacylglycerol. What is the function of IP3? a) it recruits Akt kinase to the plasma membrane b) it recruits protein kinase C to the plasma membrane c) it stimulates the release of calcium from the smooth ER d) it activates adenylyl cyclase e) none of the above

Protein components of the ESCRT system are responsible for the formation of which of the following vesicles? a) Secretory vesicles b) Transport vesicles c) Intraluminal vesicles d) Synaptic vesicles e) Vesicular-tubular clusters (VTCs)

Proteins that contain an SH3 (src homology 3) domain are likely to bind to which of the following features of a protein partner? a) phosphoserine residue b) phosphotyrosine residue c) proline-rich domain d) tyrosine-rich domain e) serine-rich domain

Which of the following best describes the events that occur after photoisomerization of 11-cis retinal in rod photoreceptor cells? a) cGMP levels increase, Na+ channels open, the cell depolarizes, and glutamate release increases b) cGMP levels decrease, Na+ channels close, the cell depolarizes, and glutamate release increases c) cGMP levels decrease, Na+ channels close, the cell hyperpolarizes and glutamate release decreases d) cGMP levels increase, Na+ channels close, the cell depolarizes, and glutamate release increases e) None of the above

Which of the following is NOT one of the 5 Essential Characteristics of All Living Cells? a) Capable of protein synthesis b) Capable of autonomous replication c) Capable of regulated mobility d) Contains nucleic acid that encodes at least one complete copy of a genome e) All of the above are among the 5 essential characteristics

Which of the following is an important function of heat shock proteins? a) They determine the substrate specificity of cyclin dependent kinases b) They are ubiquitin ligases c) They help soluble proteins fold properly d) They detect changes in cytosolic temperature e) They have no known function

Which of the following microscopic techniques supports three dimensional reconstruction from optical sections obtained from a fluorescent specimen? a) phase contrast microscopy b) differential interference contrast microscopy c) confocal laser scanning microscopy d) transmission electron microscopy e) scanning electron microscopy

Which of the following proteins is/are NOT (an) ABC transporter(s)? a) bacterial permeases b) cystic fibrosis transmembrane conductance regulator c) calcium ATPase d) multidrug resistance proteins e) all of the above are ABC transporters

Which of the following species was chosen as a model organism for the study of invertebrate development? a) Arabidopsis thaliana b) Mus musculus c) Caenorhabditis elegans d) Danio rerio e) None of the above

Which of the following statements is FALSE regarding microtubules? a) microtubules grow fastest from the plus (+) end b) microtubules are composed of 13 "protofilaments" c) microtubules undergo "catastrophe", during which, protofilaments fray at the minus (-) end d) microtubules are often stabilized by plus (+) end capping proteins e) all of the above are TRUE regarding microtubules

Signal Transducer and Activator of Transcription (STAT) proteins are phosphorylated and activated by which of the following kinases? A. Protein kinase A (PKA) B. Mitogen activated protein (MAP) kinases C. Janus kinases (JAKs) D.Akt kinase E. None of the above phosphorylate and activate STAT proteins

C. Janus kinases (JAKs)

Which of the following is phosphorylated by MAP kinase kinase kinase (Raf)? A. MAP B. MAP kinase (ERK) C. MAP kinase kinase (MEK) D. MAP phosphatase (MAPP) E. MAP phosphatase kinase (MAPPK)

C. MAP kinase kinase (MEK)

Which of the following refers to the SMC protein complex that gathers and packages newly replicated DNA into chromosomes? A. compressin B. compactin C. cohesin D. gatherin E. condensin

E. condensin

activating enzyme of ubiquitin

conjugating enzyme of ubiquitin

During ubiquitin-mediated proteolysis, which subunit of the ubiquitin ligase complex transfers a ubiquitin molecule to the epsilon amino group of a lysine residue on the target protein?

E2 subunit

During ubiquitin-mediated proteolysis, which subunit of the ubiquitin ligase complex binds to the target protein?

ubiquitin ligase

28) Is the following statement True or False? Protein kinases always activate their substrate phosphoproteins. a) The above statement is TRUE b) The above statement is FALSE

FALSE

4) Is the following statement True or False? "Homologous chromosomes occupy adjacent regions of the interphase nucleus." a) The above statement is TRUE b) The above statement is FALSE

FALSE

Which of the following is a method for the quantitative measurement of the rate of lateral diffusion of membrane proteins and lipids?

FRAP

No molecule can traverse the nuclear pore complex without the assistance of a nuclear transport receptor

False

Protein kinases always activate their substrate phosphoproteins

False

T or F? no molecule can trasverse the NPC without the assistance of a nuclear transport receptor

False

Which of the following is the largest family of cell signaling proteins encoded in the human genome?

G-protein coupled receptor

Which of the following is the largest family of cell signaling proteins encoded in the human genome?

G-protein coupled receptors

at which phase of the cell cycle do the SMC protein complexes that prevent premature separation of sister chromatids first assemble around DNA

G1 Phase

The term "interphase" refers to which of the following phase(s) of the cell cycle?

G1 phase + S phase + G2 phase

Which of the following kinase-cyclin pairs is correctly matched?

G1-S Cdk & cyclin E

Which of the following Cdk complex cyclin matches is correct

G1/S-cdk & cyclin E S-cdk & cyclin A M-cdk & cyclin B

A serious error of DNA replication would most likely arrest cells in which phase of the cell cycle?

G2 phase

As you know, the alkaloid, colchicine, promotes depolymerization of microtubules. Treatment of early frog embryos with colchicine would most likely arrest cells at which phase of the cell cycle?

G2 phase

Dynamic instability in microtubules stems from the intrinsic capacity of tubulin molecules to hydrolyze

GTP

What is the source of the energy required for transport of proteins through the nuclear pore complex (NPC)?

GTP hydrolysis

Which of the following events terminates signaling through the alpha subunit of a trimeric G-protein complex?

GTP hydrolysis

During cell signaling through G-protein coupled receptors, what event enables binding of the alpha subunit to the beta-gamma complex?

GTP hydrolysis by the alpha subunit

During receptor mediated activation of a trimeric G-protein, which of the following events terminates the signal?

GTP hydrolysis by the alpha subunit

During receptor mediated endocytosis, which of the following events releases clathrin-coated vesicles from the plasma membrane?

GTP hydrolysis by the dynamic complex

Which of the following statement regarding HSP70-type molecular chaperones is true?

GTP hydrolysis results in the binding of chaperone proteins to polar amino acids on the targets protein

What is dynamin?

GTPase that promotes vesicle release

[inactivated by pertussis toxin]

Gi PIP had a raspy voice therefore he must have had the pertussis toxin to get the whooping cough Go PIP went to go get gisselle

In epithelial cell, how is glucose transported across the basolateral membrane?

Glucose uniporter

An extracellular messenger molecule that increases intracellular calcium levels in target cells AND is blocked by pertussis toxin probably signals through which of the following trimeric G-proteins?

An extracellular messenger molecule that increases intracellular calcium levels in target cells, AND is blocked by pertussis toxin, probably signals through which of the following trimeric G-proteins?

In plants, where are pectin and hemicellulose synthesized?

Golgi

Clathrin-coated vesicles are involved in the following transport scenarios

Golgi --> plasma membrane Golgi --> endosomes plasma membrane --> endosomes pre-synaptic membrane --> endosomes

An extracellular messenger molecule that increases intracellular calcium levels in target cells, and is NOT blocked by pertussis toxin, probably signals through which of the following trimeric G-proteins?

Which of the following trimeric G-protein alpha subunits is activated by cholera toxin?

[activated by cholera toxin]

Gs s copied c therefore it activates this part of the GPCR

Which of the following G proteins signals through cGMP phosphodiesterase in retinal rod & cone cells?

role of the Rab GTPase in vesicular transport

It becomes associated with the source membrane prior to vesicle formation It identifies the target compartment of the vesicle it directs the transport machinery to deliver the vesicle to the target compartment It binds to tethering proteins on the surface of the target compartment

Which of the following is True regarding bacteriorhodopsin?

It is a light-activat4ed proton pump it has seven transmembrane alpha helices it includes a covalently-bound retinal cofactor

An ANTIPORTER mediates which of the following processes? a) co-transport of a solute molecule along its concentration gradient, and an ion against its concentration gradient in the same direction across the plasma membrane b) co-transport of a solute molecule along its concentration gradient, and an ion against its concentration gradient in opposite directions across the plasma membrane c) co-transport of a solute molecule against its concentration gradient, and an ion along its concentration gradient in the same direction across the plasma membrane d) co-transport of a solute molecule against its concentration gradient, and an ion along its concentration gradient in opposite directions across the plasma membrane e) facilitated transport

Aquaporin has a pair of key asparagine residues located on the wall almost halfway through its pore. These residues simultaneously bind to the oxygen atom of a passing water molecule, rendering it unavailable for hydrogen-bonding. As a result, ... a) the channel can conduct negatively charged (but not positively charged) ions. b) the channel can conduct glycerol as well as water. c) the channel cannot conduct glycerol. d) the channel cannot conduct protons. e) the channel cannot conduct chloride ions.

During endosomal maturation, the luminal concentration of which of the following ions gradually increases, with the highest concentration occurring in lysosomes? a) Sodium ions b) Potassium ions c) Calcium ions d) Hydrogen ions e) All of the above

For which of the following ions is the intracellular concentration typically higher than the extracellular concentration? a) sodium ions b) calcium ions c) magnesium ions d) potassium ions e) chloride ions

Growth factors signal through the PI3 kinase pathway. Which of the following protein complexes is activated during growth factor signaling, resulting in increased protein synthesis, and decreased protein degradation? a) ribosome b) RNA polymerase c) spliceosome d) mTOR complex e) none of the above

How does the calcium-dependent ER chaperone, Calnexin, recognize and bind proteins that may be misfolded? a) the proteins have exposed non-polar amino acids b) the proteins have exposed polar amino acids c) the oligosaccharide on an asparagine residue of the protein has no terminal glucose moieties d) the oligosaccharide on an asparagine residue of the protein has one terminal glucose moiety e) none of the above

In many protein complexes, amphipathic alpha helices on different protein subunits interact to form a very stable structure called ... a) a beta helix b) a double helix c) a coupled helix d) a coiled coil e) an SH2 domain

In the retina, photoisomerization of 11-cis retinal activates rhodopsin, which, in turn, activates the trimeric G-protein, Gt (transducin). Which of the following membrane associated enzymes is activated by Gt? a) guanylyl cyclase b) adenylyl cyclase c) phospholipase C d) cGMP phosphodiesterase e) cAMP phosphodiesterase

Signal Transducer and Activator of Transcription (STAT) proteins are activated by which of the following kinases? a) Protein kinase A (PKA) b) Mitogen activated protein (MAP) kinases c) Calcium-calmodulin dependent protein kinase II (CaM kinase II) d) Janus kinases (JAKs) e) none of the above

The ability of vesicles to fuse with the target membrane is maintained at the expense of ATP hydrolysis. When does ATP hydrolysis occur? a) During binding of tethering proteins b) During dissociation of Rab proteins c) During formation of SNARE complexes d) During dissociation of SNARE complexes e) All of the above

The active site of most enzymes is primarily composed of which of the following? a) adjacent polar amino acids b) adjacent non-polar amino acids c) non-adjacent non-polar amino acids d) non-adjacent polar amino acids e) all of the above

The signal recognition particle (SRP) binds to the ER sorting signal on the nascent polypeptide and arrests (stops) translation. When does translation resume? a) No more than five minutes later b) Immediately after binding of the complex to the SRP receptor c) Immediately after dissociation of the SRP from the SRP receptor d) Immediately after binding of the sorting sequence to the ER translocator e) Immediately after GTP hydrolysis by the SRP

What is the function of gamma tubulin ring complexes? a) they stabilize the plus (+) ends of microtubules b) they destabilize the plus (+) ends of microtubules c) they stabilize the minus (-) ends of microtubules d) they nucleate polymerization of microtubules e) they bind together the plus (+) ends of microtubules

What is the refractive index of water? a) 1.00 b) 1.12 c) 1.21 d) 1.33 e) 1.51

What is the structural basis for the ion selectivity of the voltage gated potassium channel? a) a sequence of positively charged amino acids along the selectivity channel b) a cluster of negatively charged amino acids near the selectivity channel c) a series of amide hydrogen atoms along the selectivity channel d) a series of carbonyl oxygen atoms along the selectivity channel e) sodium ions are too big to pass through the channel

Which of the following best describes the energy source for transport of a soluble protein into the mitochondrion? a) ATP hydrolysis b) GTP hydrolysis c) Proton gradient across the inner mitochondrial membrane d) Two of the above e) All of the above

Which of the following is FALSE regarding bacteriorhodopsin? a) it is a light-activated proton pump b) it has seven transmembrane alpha helixes c) it includes a covalently-bound retinal cofactor d) it pumps protons into of the cytosol e) all of the above are TRUE regarding bacteriorhodopsin.

Which of the following is an intermediate filament that is found in ALL eukaryotic cells? a) neurofilaments b) keratins c) vimentins d) nuclear lamins e) all of the above are intermediate filament proteins found in ALL eukaryotes

Which of the following is responsible for the DIRECTIONALITY of transport through the nuclear pore complex? a) Restriction of RAN to the cytosolic compartment b) Restriction of RAN to the nuclear compartment c) Restriction of RAN-GAP to the nuclear compartment d) Restriction of RAN-GEF to the nuclear compartment e) Restriction of RAN-GEF to the cytosolic compartment

Which of the following organelles is responsible for the synthesis of new membrane for components of the endomembrane system? a) mitochondria b) endosomes c) Golgi complex d) endoplasmic reticulum e) none of the above

Why are disulfide bridges rarely found in cytosolic domains of membrane proteins? a) because there are no cysteine residues in the cytosolic domains of membrane proteins b) because there is not enough oxygen in the cytosol to oxidize -SH groups c) because the enzymes that form disulfide bridges are not found in the cytosol d) because cytosolic constituents promote reduction of disulfide bonds e) all of the above

The SMC protein complexes that gather and organize DNA strands into chromosomes are called ... A. gatherins B. cohesins C. compactins D. condensins E. none of the above

D. condensins

Which of the following is an intermediate filament that is found in ALL eukaryotic cells? A. neurofilaments B. keratins C. vimentins D. nuclear lamins E. all of the above are intermediate filament proteins found in ALL eukaryotes

D. nuclear lamins

Which of the following processes occur only in S phase of the cell cycle?

DNA replication

The Hershey-Chase Experiment demonstrated that ...

DNA was uniquely responsible for the transformation of R. pneumoniae

Which of the following species was chosen as a model organism for the study of vertebrate development?

Danio rerio

During early development of the vertebrate central nervous system, undifferentiated epithelial cells that enter the neuronal linage signal to their neighbors by displaying which pf the following membrane proteins?

Delta

19) What discovery/invention was William Perkin's contribution to Cell Biology? a) the compound microscope b) the Stand 1 microscope c) Perkin's reaction d) the Perkin pipette e) aniline dyes

Drugs like Viagra work by inhibiting which of the following proteins? a) Sodium-potassium ATPase b) Adenylyl cyclase c) Guanylyl cyclase d) cAMP specific phosphodiesterase e) cGMP specific phosphodiesterase

During embryonic development, how does the Notch receptor signal that it has bound a Delta ligand? a) by activating a tyrosine kinase b) by increasing cyclic AMP c) by increasing cyclic GMP d) by activating PI3 kinase e) by releasing a proteolytic fragment of the receptor into the cytosol

Lysozyme is an antimicrobial enzyme found in saliva. Which of the following statements about lysozyme is FALSE? a) It is a polysaccharide hydrolase b) It binds to 6 sugar residues of the substrate c) It employs coordinated acid base catalysis d) Binding of the substrate results in distortion of the "D" ring e) All of the above are TRUE about the enzyme, lysozyme

Many anti-cancer drugs target the microtubule cytoskeleton. Which of the following best describes this class of anti-cancer drugs? a) drugs that destabilize microtubules b) drugs that stabilize microtubules c) drugs that prevent microtubule polymerization d) drugs that promote microtubule polymerization e) all of the above

Tertiary structure of proteins is primarily stabilized by which of the following? a) hydrogen bonds between elements of the amino acid backbone. b) hydrogen bonds between amino acid side chains c) ionic interactions d) van der Waals attractions between elements of the amino acid backbone. e) van der Waals attractions between hydrophobic amino acid side chains

The resting potential of the plasma membrane of an excitable cell is primarily due to the selective permeability of the membrane to which of the following ions? a) lithium ions b) sodium ions c) magnesium ions d) calcium ions e) potassium ions

What is/are caveolae? a) A special pasta prepared during summer festivals in Tuscany b) A meatball sandwich, typically served with fava beans and a fine chianti c) Tiny erosions of tooth enamel in dogs d) A small, two seat convertible automobile produced in Slovakia e) Small endocytic vesicles rich in membrane proteins and sphingomyelin

When is a misfolded protein considered to be a "prion"? a) when the protein forms aggregates b) when the protein catalyzes the misfolding of other proteins c) when the protein causes accumulation of extracellular amyloid d) when the protein causes disease e) when the protein transmits disease to other organisms

Which of the following GTPases is responsible for the release of clathrin-coated vesicles from the plasma membrane? a) Ran b) Rab c) Ras d) Rac e) Dynamin

Which of the following is FALSE regarding myelination of axons in the peripheral nervous system? a) It is carried out by Schwann cells. b) It insulates the axons to reduce current leakage. c) It increases the speed of action potential propagation through saltatory conduction. d) It conserves energy because the active excitations are restricted to the nodes of Ranvier. e) All of the above are TRUE regarding myelination of axons in the peripheral nervous system.

Which of the following is FALSE regarding the N-glycosylation process? a) N-glycosylation begins in the ER lumen b) A preformed, 14 residue oligosaccharide is transferred to the amide nitrogen of an asparagine residue on the glycoprotein c) The first 7 sugar residues of the oligosaccharide are attached to the dolichol carrier on the cytosolic side of the ER membrane d) The last three (glucose) residues of the oligosaccharide must be removed prior to incorporation of the glycoprotein into COP2 vesicles e) All of the above are TRUE regarding the N-glycosylation process.

Which of the following is most likely the fate of a protein marked with a KDEL signal sequence at the C-terminal? a) Transport through the nuclear pore complex b) Sorting to the mitochondrion c) Sorting to the peroxisome d) Sorting to late endosomes e) Return to the ER lumen

Which of the following is the largest family of cell signaling proteins encoded in the human genome? a) enzyme coupled receptors b) receptor tyrosine kinases c) trimeric G-proteins d) small GTPases e) G-protein coupled receptors

Which of the following microscopic techniques provides the highest resolution images of the surface morphology of a specimen? a) confocal laser scanning microscopy b) phase contrast microscopy c) differential interference contrast microscopy d) transmission electron microscopy e) scanning electron microscopy

Within the Golgi complex, where would you expect to find mannose-6-phosphate (M6P) receptors? a) cis-Golgi network b) cis-Golgi cisterna c) median-Golgi cisterna d) trans-Golgi cisterna e) trans-Golgi network

Inhibitory neurotransmitters like GABA hyperpolarize postsynaptic neurons by activating which of the following ion channels?

Ligand gated chloride channels

N-terminal sequences direct a secretory protein to the ER membrane for co-translational transport

MLAVALVIA

What are Caspases?

Proteases that cleave substrate at specific aspartate residues

Which of the following statement about microtubules are true

Most are composed of 13 protofilaments They are polymers of alpha-beta tubulin dimers They polymerize at the plus (+) ends

types of ABC pumps

Multi Drug Resistant proteins bacterial pm permeases cystic fibrosis transmembrane conductance regulator protein phospholipid flippases

Which is an intermediate filament found in ALL eukaryotic cells? -neurofilaments -keratins -vimentins -nuclear lamins

Nuclear lamins

Which of the following are intermediate filament proteins that are expressed in all eukaryotic cells?

Nuclear lamins

Which of the following is a function of the Golgi Complex?

O-Type glycosylation of protein Packaging and distribution of proteins Production of secretory vesicles

Which of the following is arranged in order of decreasing permeability (i.e., highest to lowest) across a phospholipid bilayer?

O2 > H2O > ethanol > Na+

During S-phase, which of the following is phosphorylated by S-cdk complex to prevent a second round of DNA synthesis?

ORC

S-Cdk complex prevents multiple DNA replication events by phosphorylating which of the following?

ORC (origin of replication complex)

Which of the following events is responsible for the depolarization phase of the action potential?

Opening of the voltage gated sodium channels

What is the function of the centriole? -it is required for the production of microtubules -it is required for the production of cilia -it is required for the production of the spindle complex -it is required for chromosomal segregation

It is required for production of cilia

During receptor mediated endocytosis of LDL particles, what happens to the LDL receptor?

It is usually returned to the plasma membrane

How does cytochrome C initiate apoptosis?

It promotes the aggregation of initiator procaspases

Prolactin and cytokines signal through which of the following?

JAK kinases

Prolactin and some cytokines alter gene expression through which of the following signal transduction pathways?

JAK-STAT pathway

Signal Transducer and Activator of Trascription (STAT) proteins are activated by what kinase? -PKA -MAP kinase -CaM kinase II -JAKs

JAKs

Signal Transducer and Activator of Transcription proteins (STATs) are activated by which of the following kinases?

Janus kinases

Active transport requires the input of energy into a system, so as to move solutes against their electrochemical and concentration gradients. Which of the following is NOT one of the common ways in which cells perform active transport?

K+ coupled

In the Golgi, ER resident proteins are gathered into COP1 vesicles by ...

KDEL receptors

Which of the following are intermediate filament proteins that are exclusively expressed in epithelial cells?

Keratins

Which of the following kinesin motor proteins binds directly to chromatins?

Kinesin 4,10

Which of the following letters represents an amino acid that is uncharged at neutral pH?

import into ER

Leu-Leu-Leu-Val-Gly-Ile-Leu-Phe-Trp-Ala- LLLVGILFWA eight or more consecutive non-polar amino acids internal NPAA sequences are interpreted as transmembrane domains

Many mitochondrial proteins are encodes in the nuclear genome. These proteins are translated in the cytosol and transported into the mitochondrion, where the first enter which of the following comportments?

The matrix

Which of the following statements is NOT true of mitochondrial proteins that are synthesized in the cytosol? Proteins are unfolded as they are transported into the mitochondria Proteins cross both the inner and outer mitochondrial membranes as they are imported Proteins are transported across the mitochondrial membranes while being synthesized Chaperone proteins help draw the proteins inside the mitochondria Proteins usually have a signal sequence at their NH2 terminus

Proteins are transported across the mitochondrial membranes while being synthesized

During insulin-mediated upregulation of glucose transporters on the plasma membrane, glucose uniporters are delivered to the plasma membrane in vesicles derived from which compartment? -recycling endosomes -multivesicular bodies -trans-golgi network -vesicular-tubular clusters

Recycling endosomes

During the insulin-mediated increase in glucose uptake into cells, glucose uniporter are delivered to the plasma membrane in vesicle derived form which of the following compartment?

Recycling endosomes

Which of the following events occurs immediately after GTP hydrolysis by elongation factor Tu?

Release of the aminoacyl t-RNA in the A-site of the ribosome

What is responsible for the directionality of transport through the Nuclear Pore Complex?

Restriction of RAN-GEF to the nuclear compartment

The directionality of the transport across the nuclear envelope via the nuclear pore complex us due primarily to which of the following conditions

Restriction of Ran-GEF to the nuclear compartment

Which is most likely the fate of a protein marked with a KDEL signal sequence at C terminal? -transport through NPC -sort to mitochondrion -sort to peroxisome -sort to late endosome -return to ER lumen

Return to ER lumen

Which of the following antibiotics blocks transcription initiation in bacteria?

Rifamycin

kinase-cyclin pairs

S Cdk and cyclin A M Cdk and cyclin B G1 Cdk and cyclin D G1/S Cdk and cyclin E

Which proteins play a central role in the fusion of a vesicle with a target membrane?

SNARE proteins

JAK kinases signal through which of the following?

STATs

Janus kinases phosphorylate which of the following signal transduction proteins?

STATs

Cell cycle regulation was primarily characterized in which of the following model species?

Saccharomyces cerevisiae

Which of the following model organism was used to elucidate the transmembrane ion conductances responsible for the generation and propagation of action potentials?

Squid

Agents that interfere with the dynamic instability of microtubules, including Taxol, cholchicine, and vincristine, are effective anti-cancer chemotherapeutics. Why is taxol less toxic to normal cells?

Taxol actually stabilizes microtubules

How does the calcium-dependent ER chaperone, Calnexin, recognize and bind proteins that might be misfolded? -the proteins have exposed NPAAs -the proteins have exposed polar AAs -the oligosaccharide on an asparagine residue of protein has no terminal glucose moiety -the oligosaccharide on the asparagine residue of the protein has 1 terminal glucose moiety

The oligosaccharide on an asparagine residue of the protein has one terminal glucose moiety

How does the calcium-dependent ER chaperone protein, Calnexin recognize and bind proteins that may be misfolded?

The oligosaccharide on the asparagine residue of the protein has one terminal glucose moiety

Which of the following is an important function of heat shock proteins?

They help soluble proteins fold properly

Which of the following statement regarding cytoplasmic is true?

They hydrolyze ATP and move toward the minus (-) end of microtubules

Which of the following statement is TRUE regarding most kinesin motor proteins?

They hydrolyze ATP and move toward the plus (+) end of microtubules

What is TRUE of most kinesin motor proteins? -they hydrolyze ATP and move toward the (+) end of the microtubule -they hydrolyze ATP and move toward the (-) end of the microtubule -they hydrolyze ATP and move toward the (+) end of the intermediate filament -they hydrolyze GTP and move toward the (+) end of the microtubule -they hydrolyze GTP and move toward the (-) end of the microtubule

They hydrolyze ATP and move toward the plus end of the microtubules

What is the function of gamma tubulin ring complexes? -they stabilize the + end of microtubules -they destabilize the + end of microtubules -they stabilize the - end of microtubules -they nucleate polymerization of microtubules -they bind together the + ends of microtubules

They nucleate polymerization of microtubules

classified as an Amyloidosis

Transmittable Spongiform Encephalopathies (e.g., "Mad Cow") Alzheimer's Disease Huntington's Disease

During the transport cycle for the sodium-potassium ATPase, which events occurs immediately after phosphorylation an aspartate residue on the phosphorylation domaterm-4ins?

Transport of 3 sodium ions from the cytosolic compartment to the extracellular compartment

During the formation of clathrin coated vesicles, a heximeric protein complex of clathrin proteins binds to adaptin molecules to form the clathrin cage. This is called

Triskelions

Cytosolic domains of plasma membrane proteins remain in the cytosol throughout transport through the Golgi

True

In some cells, activation of phospholipase C-beta causes waves of released Ca2+ to spread along the cytoplasmic surface of the endoplasmic reticulum.

True

Is the following statement TRUE or FALSE? "Cytosolic domains of plasma membrane proteins remain in the cytosol throughout transport through the Golgi."

True

Is the following statement TRUE or FALSE? "In some cells, activation of phospholipase Cbeta causes waves of Ca2+ release to spread along the endoplasmic reticulum."

True

Is the following statement TRUE or FALSE? Glycosylated residues of integral membrane proteins are always confined to extracellular domains.

True

Only the extracellular domains of membrane glycoproteins can be glycosylated.

True

T or F? Cytosolic domains of plasma membrane proteins remain in the cytosol throughout transport through the Golgi

True

T or F? Immediately after release of coated vesicle from the source membrane, the coat proteins dissociate

True

T or F? In some cells, activation of phospholipase C-beta causes waves of Ca2+ release to spread along the ER

True

Transport of soluble protein from the cytosol into the mitochondrion required the establishment of the a pH gradient across the inner mitochondrial membrane

True

immediately after release of the vesicles from the source membrane, the coat proteins dissociate

True

Which best describes the energy source for transport of a soluble protein into mitochondrion? -ATP hydrolysis -GTP hydrolysis -proton gradient across inner mitochondrial membrane -Two of the above

Two of the above

A membrane protein whose primary structure structure includes an N-terminal ER signal sequence and 2 internal run of 8 or more consecutive non-polar amino acids will undergo co-translation transport at the ER. Which of the following best describes the orientation of the membrane proteins in the ER membrane

Two transmembrane domain with the C and N terminals on the same side of the ER membrane

Which of the following statements regarding ubiquitin-mediated proteolysis is true?

Ubiquitin activation requires ATP hydrolysis The first ubiquitin molecule is attach3ed to the epsilon amino group of a lysine residue on the target protein A chain of ubiquitin molecules directs the target protein to the 20S proteasome

ubiquitin-mediated proteolysis

Ubiquitin activation requires ATP hydrolysis The first ubiquitin molecule is attached to the epsilon amino group of a lysine residue on the target protein A chain of ubiquitin molecules directs the target protein to the 20S proteasome Ubiquitin is not degraded by the 20S proteasome

) During the formation of a focal adhesion adherens junction, which of the following components of the junctional complex is unfolded to reveal vinculin binding sites and enabling the recruitment of actin filaments? a) alpha catenin b) beta catenin c) catenin 120 d) RIAM e) none of the abov

) Excitatory neurotransmitters like glutamic acid depolarize postsynaptic neurons by activating which of the following proteins? a) ligand gated sodium channels b) ligand gated potassium channels c) ligand gated chloride channels d) voltage gated sodium channels e) voltage gated potassium channels

) Neurotransmitter release from the presynaptic terminal requires the activation of which of the following ion channels? a) voltage gated calcium channels b) voltage gated chloride channels c) ligand gated potassium channels d) ligand gated calcium channels e) ligand gated chloride channels

. During the unfolded protein response, which of the following "misfolded protein sensors" in the ER membrane signals through a cytosolic ribonuclease domain by excising an intron from a pre-existing mRNA molecule? a) IRE1 b) PERK c) ATF-6 d) all of the above e) none of the above

1) In the lab, you have cultured cells that express a trimeric G protein of the Gi family. Which of the following best describes the expected result of pertussis toxin treatment on these cells? a) cAMP levels go up b) cAMP levels go down c) cGMP levels go up d) IP3 levels go up e) IP3 levels go down

10) Which of the following is an intermediate filament that is found in ALL eukaryotic cells? a) nuclear lamins b) microfilaments c) keratins d) neurofilaments e) all of the above are intermediate filament proteins found in ALL eukaryotes

10) Which process provides the force that propels the leading edge of a motile cell forward? a) actin polymerization b) microtubule polymerization c) myosin I motor activity d) myosin II motor activity e) kinesin motor activity

11) Which of the following statements is FALSE regarding microtubules? a) microtubules grow fastest from the minus (-) end b) microtubules are composed of 13 "protofilaments" c) microtubules undergo "catastrophe", during which they fray at the plus (+) end d) microtubules are often stabilized by plus end capping proteins e) all of the above are TRUE regarding microtubules

16) Complete the following sentence. " Most kinesins are ..." a) plus (+) end directed microtubule motor proteins b) minus (-) end directed microtubule motor proteins c) plus (+) end directed actin motor proteins d) minus (-) end directed actin motor proteins e) inactive structural proteins

20) Which of the following protein complexes is responsible for the nucleation of actin polymerization at the leading edge of motile cells? a) ARP complexes b) Akt complexes c) Bax complexes d) APC complexes e) none of the above

21) During myosin movement along an actin filament, which event causes release of the head domain from the actin filament. a) binding of ATP b) hydrolysis of GTP c) hydrolysis of ATP d) dissociation of ADP e) dissociation of Pi

22) In a motile cell, where would you expect to find the highest concentration of the ARP complex? a) in the lamellipodium b) in the cortex c) in the nucleus d) at the trailing end of the cell e) in the centrosome

23) Which of the following serves as the minus (-) end capping protein of actin filaments in striated muscle? a) tropomodulin b) troponin c) tropomyosin d) CapZ e) none of the above

3) Which of the following intermediate filaments is the cytoskeletal component of desmosomes between epithelial cells? a) keratins b) vimentin c) neurofilaments d) nuclear lamins e) none of the above

30) Which of the following events prevents a second round of DNA replication a) phosphorylation of ORC b) phosphorylation of cdc25 c) ubiquination of cyclin B d) ubiquination of cdc6 e) none of the above

32) Which of the following kinases is responsible for phosphorylation and inactivation of M-Cdk? a) Wee1 kinase b) MAP kinase c) Akt kinase d) S-Cdk e) cdc25

37) At the metaphase-anaphase transition, which of the following proteins is ubiquinated by APC? a) cyclin B b) cdc20 c) separin d) cohesins e) none of the above are ubiquinated by APC

39) At the metaphase-anaphase transition, which of the following proteins is ubiquinated by APC? a) cyclin B b) cdc20 c) separase d) cohesins e) none of the above are ubiquinated by APC

42) How does RB protein prevent escape from G0? a) by binding to and inhibiting E2F transcription factor b) by binding to and inhibiting P53 c) by phosphorylating P53 d) by binding to Cdk inhibitors like P21 e) actually, RB protein promotes escape from G0

42) Which of the following proteins is required to sustain G1 phase? a) cdh1 b) p53 c) cdc25 d) mTOR e) myc

44) How does RB protein prevent escape from G0? a) by binding to and inhibiting E2F transcription factor b) by binding to and inhibiting p53 c) by phosphorylating p53 d) by binding to Cdk inhibitors like p21 e) RB protein promotes escape from G0

45) Growth factors increase protein synthesis and decrease protein degradation by activating which of the following? a) mTOR b) cdh1 c) cdc20 d) p53 e) myc

47) Complete the following sentence: Caspases are ... a) proteases b) phosphatases c) ubiquitin ligases d) scaffold proteins e) kinases

6) Which of the following protein complexes is capable of nucleating actin filaments? a) formin dimers d) cofilin b) gamma tubulin ring complexes e) none are capable of nucleating actin filaments c) centrioles

7) The PI3 kinase signaling pathway results in the activation of which of the following protein kinases? a) Akt kinase b) protein kinase A c) protein kinase C d) Janus kinases e) M-Cdk

Complete the following sentence. " Most kinesins are ..." a) plus (+) end directed microtubule motor proteins b) minus (-) end directed microtubule motor proteins c) plus (+) end directed actin motor proteins d) minus (-) end directed actin motor proteins e) inactive structural proteins

During G1 phase, which of the following prevents entry into S-phase when DNA damage is present? a) p53 d) Rb b) cdh1 e) cdc25 c) cdc20

Formation of PI(3,4,5)P3 by PI3 kinase results in the recruitment of proteins that possess which of the following? a) pleckstrin homology (PH) domain b) Src Homology 2 (SH2) domain c) Src Homology 3 (SH3) domain d) PTB domain e) kinase domain

Growth factors increase protein synthesis and decrease protein degradation by activating which of the following? a) mTOR b) cdh1 c) cdc20 d) p53 e) myc

How are receptor tyrosine kinases (RTKs) activated? a) by ligand-mediated dimerization b) by binding to a G-protein c) by PKA-mediated phosphorylation d) by Akt-mediated phosphorylation e) none of the above

How does RB protein prevent escape from G0? a) by binding to and inhibiting E2F transcription factor b) by binding to and inhibiting p53 c) by phosphorylating p53 d) by binding to Cdk inhibitors like p21 e) RB protein promotes escape from G0

Is the following statement TRUE or FALSE? "Lamellipodia are autonomous motile structures driven by actin polymerization." a) The statement is TRUE b) The statement is FALSE

Is the following statement TRUE or FALSE? "When an occupied nuclear import receptor binds RAN-GTP, the cargo protein is released." a) the above statement is TRUE b) the above statement is FALSE

Mitogens promote entry into cell cycle by inactivating which of the following proteins? a) Rb b) p53 c) myc b) cyclin D a) cyclin E

What is the function of the signal recognition particle (SRP)? a) binds to ER import signal and arrests translation b) binds to the translocation channel to begin co-translational transport c) recognizes mitochondrial import signal and unfolds the protein d) assists in nuclear import of proteins e) all of the above are functions of the SRP

What is the role of dynein motor proteins in the assembly of the spindle complex? a) they bind to astral microtubules and pull the spindle poles apart b) they bind to interpolar microtubules and push the spindle poles apart c) they bind to kinetochore microtubules and push them toward chromatid pairs d) all of the above e) none of the above

Which of the following best describes the gaseous messenger, nitric oxide a) it is a paracrine messenger produced from arginine b) it is a paracrine messenger produced from asparagine c) it is an endocrine messenger produced from arginine d) it is an endocrine messenger produced from asparagine e) it is a byproduct of nitrogen metabolism

Which of the following best describes the orientation of a protein in the ER membrane that contains three internal hydrophobic domains, but no N-terminal hydrophobic domain? a) three transmembrane alpha helices with N-terminal in the cytosol b) three transmembrane alpha helices with N-terminal in the ER lumen c) two transmembrane alpha helices with N-terminal in the ER lumen d) two transmembrane alpha helices with C-terminal in the cytosol e) two transmembrane alpha helices with N-terminal and C-terminal on opposite sides of ER membrane

Which of the following events is responsible for the depolarization phase of the action potential? a) opening of voltage gated sodium channels b) opening of voltage gated potassium channels c) closing of voltage gated potassium channels d) inactivation of voltage gated sodium channels

Which of the following events prevents a second round of DNA replication a) phosphorylation of ORC b) phosphorylation of cdc25 c) ubiquination of cyclin B d) ubiquination of cdc6 e) none of the above

Which of the following fungal products binds to and stabilizes actin filaments? a) phalloidin b) cytochalasin c) swinholide d) latrunculin e) taxol

Which of the following is NOT a component of the basal lamina? a) fibronectin b) collagen c) proteoglycans d) laminin e) all of the above are components of the basal lamina

Which of the following is the calcium sensor that facilitates exocytotic release of neurotransmitter at the presynaptic terminal? a) synaptotagmin b) synaptobrevin c) syntaxin d) SNAP25 e) none of the above

Which of the following is the intermediate filament that is exclusively expressed in epithelial cells? a) keratins b) nuclear lamins c) microfilaments d) neurofilaments e) none of the above are intermediate filament proteins is exclusively expressed in epithelial cells

Which of the following kinases is responsible for phosphorylation and inactivation of M-Cdk? a) Wee1 kinase b) MAP kinase c) Akt kinase d) S-Cdk e) cdc25

Which of the following protein complexes is capable of nucleating actin filaments? a) formin dimers d) cofilin b) gamma tubulin ring complexes e) none are capable of nucleating actin filaments c) centrioles

Which of the following protein complexes is responsible for the nucleation of actin polymerization at the leading edge of motile cells? a) ARP complexes b) Akt complexes c) Bax complexes d) APC complexes e) none of the above

Which of the following proteins is most highly expressed during the unfolded protein response? a) chaperone proteins b) SNARE proteins c) nuclear transport receptors d) RNA polymerase e) Akt kinase

Which of the following proteins is required to sustain G1 phase? a) cdh1 b) p53 c) cdc25 d) mTOR e) myc

Which of the following serves as the minus (-) end capping protein of actin filaments in striated muscle? a) tropomodulin b) troponin c) tropomyosin d) CapZ e) none of the above

Which of the following small GTPases plays a key role in the mitogen activated protein (MAP) kinase pathway? a) Ras d) Ran b) Rac e) Erk c) Rab

which of the following structures is responsible for nucleating microtbule formation a. y-tublin ring complexes b. formin dimers c. arp complexes d. all of the aboce e. none above

a and c ?

Which of the following proteins releases calcium from the sarcoplasmic reticulum in response to muscle depolarization?

a calcium-gated calcium channel

What is p21?

a cdk inhibitor

Which of the following best describes the relationship between the standard free energy change (∆G0) for a reaction and the equilibrium constant (Keq) for that reaction?

a change in the delta G0 = -1.4 kcal/mole corresponds to a 10-fold increase in Keq

A dense region of the plasma membrane that has attracted clathrin coat proteins is called ...

a coated pit

In many protein complexes, amphipathic alpha helices on different protein subunits interact to form a very stable structure called ...

a coiled-coil

How does the calcium-dependent ER chaperone, Calnexin, recognize and bind proteins that may be misfolded?

a glycosylated asparagine residue on the protein has a single terminal glucose moiety

Which of the following is the most common transmembrane domain of integral membrane proteins?

a hydrophobic alpha helix

which of the following is an intermediate filament protein found exclusively in epothelial cells a. keratin b. colloagen c. vimentin d. lamin a

a keratin

A protein domain that is found in many otherwise unrelated proteins is frequently described described as which of the following?

a module

The characteristic, biconcave shape of red blood cells is maintained by which of the following?

a network of protein filaments including spectrin

During the formation of intraluminal vesicles, which of the following recruits the ESCRT0 complex to the endosomal membrane

a phosphoinositide

38) Mitogens promote entry into cell cycle by inactivating which of the following proteins? a) Rb b) p53 c) myc b) cyclin D a) cyclin E

a) Rb page 14 cell cycle 2

8) Is the following statement TRUE or FALSE? "Lamellipodia are autonomous motile structures driven by actin polymerization." a) The statement is TRUE b) The statement is FALSE

a) The statement is TRUE

16) Which of the following enzymes is responsible for the reversible inhibition of M-Cdk? a) Wee1 kinase b) cdc25 phosphatase c) S-Cdk d) CAK kinase e) none of the above

a) Wee1 kinase a) Wee1 kinase b) cdc25 phosphatase is for activating M-Cdk

13) In many protein complexes, amphipathic alpha helices on different protein subunits interact to form a very stable structure called ... a) a coiled coil b) an SH2 domain c) a beta helix d) a double helix e) a coupled helix

a) a coiled coil

49) Signaling through a G-protein coupled receptor most often results in which of the following? a) activation of a membrane-associated enzyme b) alteration in gene expression c) reorganization of the cytoskeleton d) calcium mobilization e) none of the above

a) activation of a membrane-associated enzyme

23A) During the formation of adherens junction, which of the following components of the junctional complex is unfolded to reveal vinculin binding sites and enabling the recruitment of actin filaments? a) alpha catenin b) beta catenin c) catenin 120 d) RIAM e) none of the above

a) alpha catenin page 7 cell junctions

5) In a motile cell, where would you expect to find most of the ARP complex? a) at the leading edge of the cell b) at the trailing edge of the cell c) bound to the endoplasmic reticulum d) in the cortex of the cell e) in all of the above

a) at the leading edge of the cell page 10 cytoskeleton 3

35) Which of the following is NOT a microtubule organizing center? a) centriole b) centrosome c) basal body d) spindle pole e) all of the above are microtubule organizing centers

a) centriole

13) During receptor-mediated endocytosis, the contents of clathrin-coated vesicles are sorted in which compartment? a) endosomes b) lysosomes c) trans Golgi complex d) cis-Golgi complex e) none of the above

a) endosomes goes to the ENDosome then lysosome

26) During cell signaling through G-protein coupled receptors, what event causes dissociation of the alpha subunit from the beta-gamma subunit? a) exchange of bound GDP for GTP on the alpha subunit b) exchange of bound GDP for GTP on the beta-gamma subunit c) phosphorylation of an essential tyrosine residue on the alpha subunit d) phosphorylation of an essential tyrosine residue on the beta-gamma subunit e) phosphorylation of an essential serine residue on the alpha subunit

a) exchange of bound GDP for GTP on the alpha subunit

40) Which of the following is NOT a component of the basal lamina? a) fibronectin b) collagen c) proteoglycans d) laminin e) all of the above are components of the basal lamina

a) fibronectin page 2 and 9 extracellular matrix

28) How do mitogens stimulate mitotic activity? a) inactivation of Rb b) inhibition of Hct1-APC c) degradation of p21 d) inhibition of p53 e) all of the above

a) inactivation of Rb

44b) Which of the following is FALSE regarding collagen? a) it is the most abundant protein in mammals b) every third amino acid is a glycine c) it is a trimeric, coiled coil d) vitamin C is required for biosynthesis e) all of the above are TRUE regarding collagen

a) it is the most abundant protein in mammals page 3 extracellular matrix b) every third amino acid is a glycine page 4 extracellular matrix c) it is a trimeric, coiled coil page 4 extracellular matrix d) vitamin C is required for biosynthesis page 2 extracellular matrix e) all of the above are TRUE regarding collagen

3) Which of the following is FALSE about the N-glycosylation process? a) it occurs in the cytosol b) a pre-formed 14 residue oligosaccharide is presented by the lipid carrier, dolichol c) the oligosaccharide is transferred to the amide nitrogen of a Asn residue d) the last two glucose residues are cleaved before export from the ER e) all of the above are false regarding N-glycosylation

a) it occurs in the cytosol

5) What is the role of p21 in cell cycle regulation? a) it prevents entry into S-phase b) it promotes the G2-M transition c) it prevents re-initiation of DNA replication d) it inhibits APC-Hct1 e) none of the above

a) it prevents entry into S-phase

40) How does the anti-cancer drug Taxol inhibit cell division? a) it stabilizes microtubules b) it destabilizes microtubules c) it causes actin polymerization in the wrong direction d) it initiates apoptosis e) it disrupts DNA

a) it stabilizes microtubules if they are stabilized then they are not able to bind to the chromosomes... then they can't divide

15) Which of the following is the intermediate filament that is exclusively expressed in epithelial cells? a) keratins b) nuclear lamins c) microfilaments d) neurofilaments e) none of the above are intermediate filament proteins is exclusively expressed in epithelial cells

a) keratins page 2 cytoskeleton 1, page 8 cell junctions

38) The phenomenon of "Dynamic Instability" is displayed by which of the following cytoskeletal components? a) microtubules b) actin filaments c) intermediate filaments d) all of the above e) none of the above

a) microtubules

41) During G1 phase, which of the following prevents entry into S-phase when DNA damage is present? a) p53 b) cdh1 c) cdc20 d) Rb e) cdc25

a) p53 page 15 cell cycle 2

7) Which of the following fungal products binds to and stabilizes actin filaments? a) phalloidin b) cytochalasin c) swinholide d) latrunculin e) taxol

a) phalloidin page 5 cytoskeleton 3

17) SH3 domains bind tightly to which of the following structural features? a) proline rich domains b) tyrosine residues c) phosphotyrosine residues d) alpha helix e) beta sheet

a) proline rich domains

32) Caspases are ... a) proteases b) phosphatases c) ubiquitin ligases d) scaffold proteins e) kinases

a) proteases

8) Which of the following does NOT occur in Golgi complex? a) protein synthesis b) protein glycosylation c) protein sorting d) protein surveillance e) All of the above are functions occur in the Golgi complex.

a) protein synthesis

22) Which event immediately precedes chromosomal segregation? a) proteolytic cleavage of cohesins by separase b) ubiquination of cyclin B by APC c) degradation of cdk1 d) degradation of cyclin B e) formation of the contractile ring

a) proteolytic cleavage of cohesins by separase

43) Apoptosis can be induced by which of the following? a) release of cytochrome C from mitochondria b) pro-caspase activation c) aggregation of BH123 proteins d) loss of survival factor signaling e) all of the above

a) release of cytochrome C from mitochondria page 5 apoptosis b) pro-caspase activation page 5 apoptosis c) aggregation of BH123 proteins page 6 apoptosis d) loss of survival factor signaling page 7 apoptosis e) all of the above

11) What is the smallest contractile unit in striated muscle cells? a) sarcomere b) sarcoplasmic reticulum c) sarcophagus d) thick filament e) myofibril

a) sarcomere

6) Which of the following microscopic techniques provides the highest resolution images of the surface morphology of a specimen? a) scanning electron microscopy b) transmission electron microscopy c) confocal laser scanning microscopy d) phase contrast microscopy e) differential interference contrast microscopy

a) scanning electron microscopy

34) Which mode of representation of the tertiary structure of a protein provides the most information about the location and orientation of secondary structural elements? a) schematic / ribbon model b) alpha trace model c) ball and stick model d) filled structural model e) water accessible surface model

a) schematic / ribbon model

50) What is the role of dynein motor proteins in the assembly of the spindle complex? a) they bind to astral microtubules and pull the spindle poles apart b) they bind to interpolar microtubules and push the spindle poles apart c) they bind to kinetochore microtubules and push them toward chromatid pairs d) all of the above e) none of the above

a) they bind to astral microtubules and pull the spindle poles apart page 2 and 3 cell cycle 2

47) Which of the following is false regarding cadherins? a) they form heterophilic interactions b) binding affinity is reduced when the extracellular calcium concentration is elevated c) members of the catenin protein family link them to cytoskeletal proteins d) they exclusively form cell-cell junctions e) all of the above are true regarding caherins

a) they form heterophilic interactions with ca2+ the binding increases they have homophillic interactions they are not only cell to cell interaction b/c of other molecules

58) At the anaphase checkpoint, which of the following events must occur for mitosis to continue? a) ubiquination of cyclin B by APC b) phosphorylation of M-Cdk c) inactivation of p53 d) dephosphorylation of cdc25 e) none of the above

a) ubiquination of cyclin B by APC APC is anaphase promoting factor. Degradaton of M-‐cyclin(cyclinB) is required for completion of mitosis When metaphase is successful, APC releases the cell cycle machinery to ini:ate anaphase

60) Anaphase promoting complex (APC) is a ... a) ubiquitin ligase b) transcription factor c) protein kinase d) phosphoprotein phosphatase e) none of the above

a) ubiquitin ligase ligaes joins molecules together. thus this ligates ubi and the cohesions (so that you can have anaphase)

which of the following best describes the orientation of an er membrane protein containing a single run of 18 small non polar amino acids located in the middle pf the protein a. a single transmembrane domain with the n terminal domain in the cytosol

In early anaphase, APC is activated by cdc20. During G1, when cdc20 is depleted, APC activity is maintained by which of the following proteins? a. Cdh1 b. G1-Cdk c. Rb d. G1-S Cdk e. p21

a. Cdh1

46. Active transport requires the input of energy into a system, so as to move solutes against their electrochemical and concentration gradients. Which of the following is NOT one of the common ways in which cells perform active transport? a. K+ coupled b. Na+ coupled c. ATP-driven d. light-driven e. all of the above are common ways that cells perform active transport

a. K+ coupled

31. Which of the following is arranged in order of decreasing permeability (i.e., highest to lowest) across a phospholipid bilayer? a. O2 > H2O > ethanol > Na+ b. H2O > ethanol > O2 > Na+ c. ethanol > Na+ > O2 > H2O d. Na+ > ethanol > H2O > O2 e. Na+ > O2 > ethanol > H2O

a. O2 > H2O > ethanol > Na+

38. Which of the following transporter proteins undergoes covalent modification during the transport cycle? a. P-type pump b. F/V-type pump c. ABC-type pump d. symporter e. ion channel

a. P-type pump

Signal induced changes in the architecture of the actin cytoskeleton are mediated by members of the Rho family of small GTPases. Which Rho family member facilitates the formation of stress fibers? a. Rho b. Ras c. Rac d. Rab5 e. Cdc42

a. Rho

Which of the following protein kinases is responsible for the phosphorylation of M-Cdk at the inhibitory site? a. Wee1 kinase b. S-Cdk c. Polo kinase d. CAK e. none of the above

a. Wee1 kinase

During Delta-Notch signaling, a factor is generated in the target cell that enters the nucleus and alters gene expression. Which of the following enzymes generates this factor? a. a protease b. a phosphatase c. protein kinase A d. protein kinase C e. phospholipase C-"

a. a protease

which of the following is false regarding the actin filaments a. actin filaments are formed through the polyermization of gtp bound actin subunits b. most actin subunits in a filament are in contact with 4 other subunits c. polymerization only happens at the plus end of actin filaments d. nucleoside hydrolysis results in dissociation of actin subunits at the minus end of the filaments e. all of the above

a. actin filaments are formed through the polymerization of gtp bound actin filaments

which of the following is flase regarding actin filaments a. actin filaments are formed through the polymerization of gtp-bound actin subunits b. most actin subunits in a filament are in contact with 4 other subunits c. polymerization only happens at the plus end of an actin filament d. nucleotide hydrolysis results in dissociation of actin subunits at the minus end of the filament e. all above are true

a. actin filaments are formed through the polymerization of gtp-bound actin subunits

What provides the force that drives protrusion of the leading edge of a motile cell? a. actin polymerization b. microtubule polymerization c. myosin I motors d. myosin II motors e. dynein motors

a. actin polymerization

what provides the force that drives protrusion of the leading edge of a motile cells a. actin polyermization b. microtubule polymerization c. myosin I motos d. myosin II motors e. dyemin motors

a. actin polymerization

which process provides the force that propels the leading edge of a motile cell forward a. actin polymerization b. microtubule polymerization c. mysin I motor activity d. myosin II motor activity e. kinesin motor activity

a. actin polymerization

which of the following proteins is most concentrated at the leading edge of a motile cell a. actin related proteins b. actin binding proteins c. formins d. myosin I e. all of the above

a. actin releateed proteins

signaling through a g protein coupled receptor usually reesults in which of the following a. activation of a membrane assoicated enzyme b. alteration in gene expression c. reorganization of the cytoskelton d. calcium release

a. activation of a membrane associated enzyme

signaling through a g-protein coupled receptor most often results in which of the following a. activation of a membrane assoicated enzyme b. alteration in gene expression c. reorganization of the cytoskeletion d. calcium mobilization

a. activation of a membrane associated enzyme

The BH123 proteins Bax & Bak promote apoptosis by ... a. aggregating to form channels in the mitochondrial outer membrane b. turning on the expression of pro-apoptotic genes c. binding to and inhibiting the Bcl2 protein d. stimulating the production of cytochrome C e. Bax & Bak actually promote cell survival

a. aggregating to form channels in the mitochondrial outer membrane

some survival signals prevent apoptosis by phosphorylation of the bad protein resulting in the release of the anti apoptotic protein bc12. which of the following kinases phosphorylates the bad protein a. akt kinase b. protein kinase a c. protein kinase c d. map kinase e. none of the above

a. akt kinase

the gaseous messenger, nitric oxide, is ezymatically produced from which of the following a. argininie b. citrulline c. nitrate ions d. nitrite ions e. petin

a. arginine

which of the following protein complexes is responsible forthe for the nucleation of acin polymeerization at the leading edge of motile cells a. arp complexes b. akt complexes c. bax complexes d. apc complexes e. none of the above

a. arp complexes

which of the following proteins is concentrated at the leading edge of motile cell a. arps b. formins c. mysosin d. myosin II e. all of the above

a. arps

which of the following results in the release of actin filaments by myosin motor head a. atp bindings b. atp hydrolysis c. adp release d. pi release e. gtp binding

a. atp bindings

During signaling through a receptor tyrosine kinase (RTK), which of the following events immediately follows receptor dimerization? a. autophosphorylation of tyrosine residues on both receptors b. phosphorylation of tyrosine residues on both receptors by Janus kinases c. activation of a trimeric G-protein d. activation of a small GTPase (e.g., Ras) e. none of the above

a. autophosphorylation of tyrosine residues on both receptors

during signaling through a receptor tryosine kinase wehich of the following eveents immediately followd receptor dimerixation a. autophorylation of tyrosine residues on both receptors b. phosphorylation of tyrosin reesidues on both receptors by janus kinases c. activation of a trimeric g protein d. activation of a small gtpase e. none of the above

a. autophosphrylation of tyrosine residues on both receptor

what is the function of the signal recognition particle a. binds to er import signal and arrests translation b. binds to the translation channel to begin co translation transport c. recognizes mitochondrial import signal and unfolds the protein d. assists in nuclear import of proteins e. none of the above

a. binds to er import signal and arrests translation

9. In which direction does the DNA polymerase synthesize DNA? a. both strands are synthesized 5' to 3' b. both strands are synthesized 3' to 5' c. leading strand is 5' to 3', lagging strand is 3' to 5' d. leading strand is 3' to 5', lagging strand is 5' to 3' e. depends on the orientation of the template strand

a. both strands are synthesized 5' to 3' if made 5 to 3 then you need to keep adding onto the 3 side (with the 3'OH)

how does rb protein prevent escape from go a. by binding to and inhibiting e2f transcription factor b. by binding to and inhibiting p53 c. by phosphorylating p53 d. by binding to cdk inhibitors like p21 e. rb protein promotes escape from go

a. by binding to and inhibiting e2f transcription factor

10. How does the process of alternative splicing increase the structural diversity of proteins produced by a single gene? a. by excluding exon segments from the mature mRNA b. by changing the order of the exon segments in the mature mRNA c. by leaving intron segments of the gene in the mature mRNA d. by limiting the number of exon segments in the mature mRNA e. all of the above

a. by excluding exon segments from the mature mRNA

most g protein coupled receptors encoded in the human genome signal through which of the following intracellular messengers a. camp b. cgmap c. calcium d. ip3 e. diacylglycerol

a. camp

which of the following proteins is required to substain g1 phase a. cdh1 b. o53 c. cdc25 d. mtor e. myc

a. cdh 1

which of the following is not a microtubule organizing centeer a. centriole b. centromsom c. basal body d. spindle pole e. all of the above

a. centriole

which of the following is not a microtubule organizing center a. centriole b. centrosome c. basal body d. spindle pole e. all of the above

a. centriole

Which of the following is NOT a microtubule organizing center? a. centrioles b. centrosome c. basal body d. spindle pole e. all of the above are microtubule organizing centers

a. centrioles

which of the following is not a microtubule organizing center a. centrioles b. centrosome c. basal body d. spindle pole e. all of the above

a. centrioles

Why are disulfide bridges rarely found in cytosolic domains of membrane proteins?

because cytosolic constituents promote reduction of disulfide bonds

In the light microscope, the condenser lens group is ...

between the light source and the specimen

Which of the following is false regarding cadherins? they form homophilic interactions binding affinity is reduced when the extracellular calcium concentration is elevated members of the catenin protein family link them to cytoskeletal proteins they exclusively form cell-cell junctions

binding affinity is reduced when the extracellular calcium concentration is elevated

During myosin movement along an actin filament, which event causes release of the head domain from the actin filament.

binding of ATP

During M phase, anaphase promoting complex (APC) is activated by

binding of cdc20

During M phase, anaphase promoting complex (APC) is activated by which of the following?

binding of cdc20

required for the activation of M-Cdk

binding of cyclin B phosphorylation of M-Cdk at the stimulatory site dephosphorylation of M-Cdk at the inhibitory site

During co-translational transport, which of the following events interrupts translation of the nascent polypeptide?

binding of the SRP near the A site of the ribosome

What is the function of the signal recognition particle (SRP)?

binds to ER import signal and arrests translation

Streptomycin

block initiation by stopping the binding of the large substrate

Tetracycline

blocks binding of AA tRNA to start sight

Cycloheximide

blocks large subunit translocation

Rifamycin

blocks the initiation of RNA chains by binding to RNA polymerase

The drug taxol binds tightly to microtubules and prevents them from depolymerizing. The drug colchicines tightly binds to free tubulin and prevents its polymerization into microtubules. Which of these drugs arrests dividing cells in mitosis?

both

Which of the following events occurs during prometaphase?

breakdown of the nuclear envelope maturation of the spindle complex fixation of kinetochore microtubules

How do activated T-cells initiate apoptosis via the extrinsic pathway

by activating the Fas death receptor on target cells

How does RB protein prevent escape from G0?

by binding to and inhibiting E2F transcription factor

How are receptor tyrosine kinases (RTKs) activated?

by ligand-mediated dimerization

How is the progress of proteins processed through the Golgi complex monitored?

by modifications of the N-oligosaccharide

How does the Akt kinase promote cell survival?

by phosphorylating and inactivating the BAD protein

How does the Akt kinase promote cell survival? -by phosphorylating and inactivating the BAD protien -by phosphorylating and activating the BAD protein -by dephosphorylating and inactivating the BAD protein -by phosphorylating and activating the Bcl2 protein -by dephosphorylating and activating the Bcl2 protein

by phosphorylating and inactivating the BAD protein

How does the AKT kinase inhibit apoptosis?

by phosphorylating the BAD protein and releaseing the anti-apoptotic protein Bcl2

How does P53 activation prevent entry into S-Phase?

by promoting the synthesis of Cdk inhibitors

When significant DNA damage is detected during G1 phase, P53 released from inhibition and arrests cell cycle at the start checkpoint to prevent replication of damage DNA. How does P53 prevent entry into S phase

by promoting the transcription of Cdk inhibitor

During embryonic development, how does the Notch receptor signal that it has bound a Delta ligand?

by releasing a proteolytic fragment of the receptor into the cytosol

How do living cells satisfy the Second Law of Thermodynamics?

by releasing heat into the environment

Prior to vesicle formation, how are adaptins recruited to the appropriate membrane.

by specific phosphoinositides on the cytosolic surface

How does the ATP-dependent chromatin remodeling system detect nucleosomes that require "remodeling"?

by the pattern of covalent modifications of the histones within the nucleosome

How do proteins travel from one cistern to the next in the Golgi?

by transport vesicles that bud off from one cistern and fuse with the next cistern

) How is cyclin B inactivated at the metaphase-anaphase transition? a) it is phosphorylated by M-Cdk d) it is destroyed by separase b) it is phosphorylated by S-Cdk e) it is not known c) it is ubiquinated by APC

14) During myosin movement along an actin filament, which event causes release of the head domain from the actin filament. a) hydrolysis of ATP b) hydrolysis of GTP c) binding of ATP d) dissociation of ADP e) dissociation of Pi

18) Which of the following best describes the microtubular structure of the axoneme of spermatozoa? a) nine sets of singlet microtubules surrounding two doublet microtubules b) nine sets of doublet microtubules surrounding one singlet microtubule c) nine sets of doublet microtubules surrounding two singlet microtubules d) nine sets of triplet microtubules surrounding one singlet microtubule e) nine sets of triplet microtubules surrounding two singlet microtubules

19) Which of the following is NOT composed of actin filaments? a) microvilli of epithelial cells b) contractile ring c) neuronal axon d) lamellipodia e) stress fibers

22) What is the smallest contractile unit in striated muscle cells? a) sarcophagus b) sarcoplasmic reticulum c) sarcomere d) sarcaster e) myosome

23) What is the smallest contractile unit in striated muscle cells? a) sarcophagus b) sarcoplasmic reticulum c) sarcomere d) thick filament e) myofibril

25) Which of the following proteins releases calcium from the sarcoplasmic reticulum in response to muscle depolarization? a) the nicotinic cholinergic receptor b) a voltage-gated calcium channel c) a calcium-gated calcium channel d) an M-type calcium ATPase e) a sodium-calcium antiporter

29) Which of the following kinase-cyclin pairs is incorrectly matched? a) S Cdk & cyclin A b) M Cdk & cyclin B c) G1 Cdk & cyclin C d) G1-S Cdk & cyclin E e) All are correctly matched

35) Mitogens promote entry into cell cycle by inactivating which of the following proteins? a) cdc20 b) p53 c) Rb d) cyclin D e) APC

38) Which of the following is phosphorylated by the M-Cdk complex? a) p53 b) securin c) nuclear lamin B d) p21 e) all of the above are substrates for M-Cdk

47) Complete the following sentence: The anti-apoptotic protein, Bcl2, prevents apoptosis by ... a) returning cytochrome C to the mitochondrion b) promoting the aggregation of "BH123" proteins c) preventing the aggregation of "BH123" proteins d) preventing the aggregation of "BH3 only" proteins e) Bcl2 protein actually promotes apoptosis

49) Which of the following cell-cell junctions is responsible for preventing the diffusion of solutes between apical and basolateral extracellular compartments in epithelial tissues? a) desmosomes d) adherens junctions b) hemidesmosomes e) gap junctions c) tight junctions

5) Which of the following small GTPases plays a key role in the mitogen activated protein (MAP) kinase pathway? a) Rab d) Raf b) Rac e) Ran c) Ras

6) An extracellular messenger molecule that increases intracellular calcium levels in target cells, AND is blocked by pertussis toxin, probably signals through which of the following trimeric G-proteins? a) Gs d) Gq b) Gi e) Gt c) Go

7) Removal of the of the centrioles from a eukaryotic cell would result in which of the following? a) disruption of actin cytoskeleton b) disruption of microtubule cytoskeleton c) loss of cilia d) necrosis e) apoptosis

At the metaphase-anaphase checkpoint, which of the following events must occur for mitosis to proceed? a) ubiquination of APC b) phosphorylation of separin c) ubiquination of cyclin B d) phosphorylation of cyclin B e) none of the above

During co-translational transport, which of the following events interrupts translation of the nascent polypeptide? a) emergence of the ER signal sequence from the ribosome b) binding of the signal recognition particle (SRP) to the ER signal sequence on the nascent polypeptide. c) binding of the SRP near the "A" site of the ribosome d) binding of the SRP to the SRP receptor e) binding of the ER signal sequence to the stop-transfer site on the translocon

During myosin movement along an actin filament, which event causes release of the head domain from the actin filament. a) hydrolysis of ATP b) hydrolysis of GTP c) binding of ATP d) dissociation of ADP e)dissociation of Pi

During transport through the V-type ATP-dependent proton pump, how many protons are transported per ATP hydrolyzed? a) 1 proton pumped per ATP hydrolyzed b) 2 protons pumped per ATP hydrolyzed c) 4 protons pumped per ATP hydrolyzed d) 6 protons pumped per ATP hydrolyzed e) 8 protons pumped per ATP hydrolyzed

Ethler Danlos disease is characterized by defects in the synthesis of which of the following proteins? a) laminin d) keratin b) fibronectin e) elastin c) collagen I

How does p53 activation prevent entry into S-Phase? a) by promoting the expression of cyclin E b) by phosphorylating S-cdk c) by promoting the synthesis of Cdk inhibitors d) by inhibiting APC e) by inhibiting the production of G1S-cdk components

How does the calcium-dependent ER chaperone, Calnexin, recognize and bind proteins that may be misfolded? a) the proteins have exposed polar amino acids b) the proteins have exposed non-polar amino acids c) a glycosylated asparagine residue on the protein has a single terminal glucose moiety d) a glycosylated asparagine residue on the protein has no glucose moieties e) none of the above

In a Lineweaver-Burk plot of the dependence of enzyme velocity on substrate concentration, what is the value of the function at X=0 (i.e., the Y-intercept)? a) -Vmax d) -1/Km b) -1/Vmax e) 1/Km c) 1/Vmax

In the trans-Golgi network, pro-enzyme hydrolases destined for late endosomes are identified by which of the following features? a) an endosomal signal sequence b) a specific pattern of phosphorylation c) a mannose-6-phosphate moiety on the oligosaccharide d) covalent lipid tags e) it is not known

Mitogens promote entry into cell cycle by inactivating which of the following proteins? a) cdc20 b) p53 c) Rb d) cyclin D e) APC

Removal of the of the centrioles from a eukaryotic cell would result in which of the following? a) disruption of actin cytoskeleton b) disruption of microtubule cytoskeleton c) loss of cilia d) necrosis e) apoptosis

Scurvy is a disease characterized by defects in the synthesis of which of the following proteins? a) laminin d) keratin b) fibronectin e) elastin c) collagen I

What is the smallest contractile unit of a striated myocyte (muscle cell)? a) sarcoma b) sarcoplasmon c) sarcomere d) sarcophagus e) sarcasmotron

Which of the following actin binding proteins is capable of nucleating the formation of new actin filaments? a) filamin b) fimbrin c) formin d) fibrin e) none of the above are capable of nucleating the formation of new actin filaments.

Which of the following best describes the apical-to-basolateral order of occurrence of cell-cell junctions in an epithelial cell? a) tight junctions - adherens junctions - gap junctions - desmosomes b) tight junctions - desmosomes - adherens junctions - gap junctions c) tight junctions - adherens junctions- desmosomes - gap junctions d) adherens junctions - tight junctions - desmosomes - gap junctions e) adherens junctions - tight junctions - gap junctions -- desmosomes

Which of the following best describes the microtubular structure of the axoneme of spermatozoa? a) nine sets of singlet microtubules surrounding two doublet microtubules b) nine sets of doublet microtubules surrounding one singlet microtubule c) nine sets of doublet microtubules surrounding two singlet microtubules d) nine sets of triplet microtubules surrounding one singlet microtubule e) nine sets of triplet microtubules surrounding two singlet microtubules

Which of the following cell-cell junctions is formed by cell adhesion molecules that are associated with intermediate filaments? a) tight junctions d) hemidesmosomes b) adherens junctions e) gap junctions c) desmosomes

Which of the following events occurs immediately after GTP hydrolysis by elongation factor Tu (EF-Tu). a) binding of the complex to the A-site of the ribosome b) binding of the aminoacyl t-RNA c) release of the aminoacyl t-RNA d) degradation of the aminoacyl t-RNA e) exchange of bound GDP for GTP

Which of the following is FALSE regarding collagen? a) it is the most abundant protein in mammals b) every third amino acid is a glycine c) it is a dimeric, coiled coil. d) vitamin C is required for biosynthesis e) all of the above are TRUE regarding collagen

Which of the following is NOT composed of actin filaments? a) microvilli of epithelial cells b) contractile ring c) neuronal axon d) lamellipodia e) stress fibers

Which of the following is phosphorylated by MAP kinase kinase kinase (Raf)? a) MAP b) MAP kinase c) MAP kinase kinase d) MAP phosphatase e) MAP phosphatase kinase

2) Which of the following species was chosen as a model organism for the study of invertebrate development? a) Arabidopsis thaliana b) Drosophila melanogaster c) Caenorhabditis elegans d) Danio rerio e) None of the above

c) Caenorhabditis elegans

17) Your lab is investigating the signaling pathway through which a newly discovered peptide, "Peptide X" signals through a G-protein coupled receptor. You observe that addition of Peptide X to cultured epithelial cells results in the accumulation of IP3 in the cytoplasm. This effect is blocked by pertussis toxin, but not by cholera toxin. Which of the following G proteins is most likely responsible for Peptide X signaling in epithelial cells? a) Gs b) Gi c) Go d) Gq e) Gt

c) Go

48) Which of the following proteins releases calcium from the sarcoplasmic reticulum in response to muscle depolarization? a) the nicotinic cholinergic receptor b) a voltage-gated calcium channel c) a calcium-gated calcium channel d) a P-type calcium ATPase e) a sodium-calcium antiporter

c) a calcium-gated calcium channel the RyR receptor on the SR rel a little Ca. then this little Ca rel the Ca in the SR. this is caused Ca induced Ca rel

39) The BH123 proteins Bax & Bak promote apoptosis by ... a) binding to and inhibiting the Bcl2 protein b) stimulating the production of cytochrome C c) aggregating to form channels in the mitochondrial outer membrane d) turning on the expression of pro-apoptotic genes e) Bax & Bak actually promote cell survival

c) aggregating to form channels in the mitochondrial outer membrane 123 are the steps to induce apop but Bax and Bak

30) What is a "molten globule"? a) the fifth state of matter b) a denatured protein c) an intermediate protein conformation that occurs during protein folding d) an intermediate protein conformation that occurs during allosteric modulation e) none of the above

c) an intermediate protein conformation that occurs during protein folding

31) During M phase, anaphase promoting complex (APC) is activated by ... a) proteolytic cleavage by separase b) polyubiquination c) binding of cdc20 d) dephosphorylation by cdc25 e) dissociation of p21

c) binding of cdc20

14) Activation of the protein kinase A (PKA) signaling pathway does NOT involve which of the following events? a) dissociation of the alpha subunit of Gs from the beta-gamma subunit b) activation of adenylyl cyclase c) binding of cyclic AMP to the catalytic subunit of PKA d) dissociation of the regulatory subunit from the catalytic subunits of PKA e) exchange of GTP for GDP bound to Gs

c) binding of cyclic AMP to the catalytic subunit of PKA

36) Which of the following is FALSE regarding tubulin dimers? a) they are composed of alpha and beta subunits b) both the alpha and beta subunits bind GTP c) both subunits are capable of GTP hydrolysis d) the beta subunit is always exposed at the plus end of the microtubule e) all of the above are true regarding tubulin dimmers

c) both subunits are capable of GTP hydrolysis only the + beta can do gtp hydro

22) Enzymes increase the rate of chemical reactions by ... a) by lowering the Free Energy of the reactants b) by lowering the Free Energy of the products c) by lowering the activation energy for the reaction d) by changing the equilibrium constant to favor the reaction e) none of the above

c) by lowering the activation energy for the reaction

42) Which of the following CAMs are components of adherens junctions and desmosomes? a) selectins d) N-CAMs b) integrins e) I-CAMs c) cadherins

c) cadherins C-adherens cadherins are a part of desmosomes and adherens

46) Ethler Danlos disease is characterized by defects in the synthesis of which of the following proteins? a) laminin b) fibronectin c) collagen I d) keratin e) elastin

c) collagen I page 1 extracellular matrix

45) Scurvy is a disease characterized by defects in the synthesis of which of the following proteins? a) laminin d) keratin b) fibronectin e) elastin c) collagen I

c) collagen I page 5 extracellular matrix

30) Which of the following cell-cell junctions is formed by cell adhesion molecules that are associated with intermediate filaments? a) tight junctions b) adherens junctions c) desmosomes d) hemidesmosomes e) gap junctions

c) desmosomes page 7 cell junctions

2) Which of the following actin binding proteins is capable of nucleating the formation of new actin filaments? a) filamin b) fimbrin c) formin d) fibrin e) none of the above are capable of nucleating the formation of new actin filaments.

c) formin page 3 cytoskeleton 3

44a) Which of the following is FALSE regarding collagen? a) it is the most abundant protein in mammals b) every third amino acid is a glycine c) it is a dimeric, coiled coil d) vitamin C is required for biosynthesis e) all of the above are TRUE regarding collagen

c) it is a dimeric, coiled coil page 4 extracellular matrix (it is trimeric)

29) How is cyclin B inactivated at the metaphase-anaphase transition? a) it is phosphorylated by M-Cdk d) it is destroyed by separase b) it is phosphorylated by S-Cdk e) it is not known c) it is ubiquinated by APC

c) it is ubiquinated by APC page 7 cell cycle 2

35) During apoptosis, how does cytochrome C get out of the mitochondrion? a) it aggregates to form clusters that are membrane permeable b) it unfolds with the help of molecular chaparones and exits at contact zones c) it leaves through channels formed by BH123 proteins d) by receptor mediated exocytosis e) it doesn't leave the mitochondria

c) it leaves through channels formed by BH123 proteins these are the "steps" 123 to induce apoptosis

37) Which of the following statements is FALSE? a) microtubules grow fastest from the plus end b) microtubules are composed of 13 "protofilaments" c) microtubules undergo "catastrophe", during which they fray at the minus end d) microtubules are often stabilized by plus end capping proteins e) all of the above are TRUE.

c) microtubules undergo "catastrophe", during which they fray at the minus end they fray from the + end (where the gtp hydro activity occurs)

25) The active site of most enzymes is usually comprised of which of the following? a) adjacent polar amino acids b) adjacent non-polar amino acids c) non-adjacent polar amino acids d) non-adjacent non-polar amino acids e) all of the above

c) non-adjacent polar amino acids

40) The anti-apoptotic protein, Bcl2, prevents apoptosis by ... a) binding to cytochrome C b) inactivating caspases c) preventing the aggregation of Bax & Bak d) promoting the expression of survival genes e) none of the above

c) preventing the aggregation of Bax & Bak

5) Directional transport through nuclear pore complexes is primarily due to which of the following? a) a gradient of GTP across the nuclear envelope b) a gradient of ATP across the nuclear envelope c) restriction of RAN-GEF to the nuclear compartment d) restriction of RAN-GAP to the nuclear compartment e) restriction of RAN-GEF to the cytosolic compartment

c) restriction of RAN-GEF to the nuclear compartment (the cytosol is the GAP in the cell so that is where RAN-GAP stays.) (the nuclEus is is full of GEFFS that keep things in mexico)

10) What is the smallest contractile unit of a striated myocyte (muscle cell)? a) sarcoma b) sarcoplasmon c) sarcomere d) sarcophagus e) sarcasmotron

c) sarcomere page 12 cytoskeleton 3

7) The spatial resolution of optical microscopy is primarily a function of which of the following? a) the quality of the glass b) the thickness of the specimen c) the wavelength of the light d) the cost of the microscope e) none of the above

c) the wavelength of the light

45) Which of the following is false regarding glycosaminoglycans ? a) they are components of proteoglycans b) they are abundant in the extracellular space c) they are large, branched polysaccharides d) most are rich in N-acetylglucosamine e) all of the above are true regarding glycosaminoglycans

c) they are large, branched polysaccharides (GAGs)

33) During cytokine signaling through the JAK-STAT pathway, how are STAT proteins phosphorylated? a) very carefully b) they autophosphorylate c) they are phosphorylated by the JAKs d) they are phosphorylated by the cytokine receptor kinases e) STATs are NOT phosphorylated during cytokine signaling

c) they are phosphorylated by the JAKs

13) Which of the following best describes the apical-to-basolateral order of occurrence of cell-cell junctions in an epithelial cell? a) tight junctions - adherens junctions - gap junctions - desmosomes b) tight junctions - desmosomes - adherens junctions - gap junctions c) tight junctions - adherens junctions- desmosomes - gap junctions d) adherens junctions - tight junctions - desmosomes - gap junctions e) adherens junctions - tight junctions - gap junctions -- desmosomes

c) tight junctions - adherens junctions- desmosomes - gap junctions page 5 cell junctions

21) At the anaphase checkpoint, which of the following events must occur for mitosis to proceed? a) inactivation of p53 b) phosphorylation of M-Cdk c) ubiquination of cyclin B d) dephosphorylation of cdc25 e) none of the above

c) ubiquination of cyclin B you need to cleave cohesions to START anaphase and then get rid of cyclin b to PROCEED

35) At the metaphase-anaphase checkpoint, which of the following events must occur for mitosis to proceed? a) ubiquination of APC b) phosphorylation of separin c) ubiquination of cyclin B C d) phosphorylation of cyclin B e) none of the above

c) ubiquination of cyclin B C page 7 cell cycle 2

which of the following ammino acid sequences identifies an er - resident protein a. - pro-pro-lys-lys-lys-arg-lys-val b. -ser-lys-leu c. -lys-asp-glu-leu-cooh d. -met-met-leu-leu-leu-val-gly-ile-leu-phe-trp-ala-thr-glu e. none of the above

c. -lys-asp-glu-leu-cooh

42. What is the average error (wrong base) rate for a proofreading DNA polymerase? a. 1 in 103 b. 1 in 105 c. 1 in 107 d. 1 in 109 e. Once in a "Blue Moon"

c. 1 in 10^7

48. The Cystic Fibrosis Transmembrane Regulator is a member of which of the following transporter families? a. P-type pump d. symporter b. F/V-type pump e. ion channel c. ABC-type pump

c. ABC-type pump

Which of the following proteins is concentrated at the leading edge of a motile cell? a. myosin I b. myosin II c. ARPs d. formins e. all are concentrated at the leading edge

c. ARPs

What is p21? a. component of anaphase promoting complex (APC) b. component of the pre-initiation complex c. Cdk inhibitor d. the page between p20 and p22 e. none of the above

c. Cdk inhibitor

A serious error of DNA replication would most likely arrest cells in which phase of the cell cycle? a. G1 phase b. S phase d. M phase c. G2 phase e. all phases

c. G2 phase

As you know, the alkaloid, colchicine, promotes depolymerization of microtubules. Treatment of early frog embryos with colchicine would most likely arrest cells at which phase of the cell cycle? a. G1 phase b. S phase c. G2 phase d. M phase e. G2-M checkpoint

c. G2 phase

peptide x signals after a g protein coupled receptor. you observe that addition of peptide x to cultured epitheial cells results in the accumulation of IP3 in the cytoplasm. this effect is NOT blocked by pertussis toxin. which of the following G proteins is most likely responsible for peptide x signaling in epithelial cells a. Gs b. Gi c. Go d. Gq e. Gt

c. Go

2. The initiator tRNA is different from all other tRNAs in what way? a. It does not have a bound amino acid b. The anticodon is complementary to the start codon (AUG) c. It can bind directly to the P-site on the small subunit d. It binds to the large subunit before mRNA binds e. It is only found in prokaryotes

c. It can bind directly to the P-site on the small subunit cause if the initiator can't then how could transcription ever start

Which of the following events occurs during signaling through cytokine receptors? a. the Ras oncogene activates the MAPK cascade b. a gene regulatory protein is produced by selective proteolysis c. Janus kinases (JAKs) phosphorylate STAT proteins d. the Type 1 receptor phosphorylates Smad 2/3 e. β-catenin accumulates and enters the nucleus

c. Janus kinases (JAKs) phosphorylate STAT proteins

5. Which RNA polymerase is responsible for transcription of eucaryotic DNA encoding protein? a. RNA polymerase IV b. RNA polymerase III c. RNA polymerase II d. RNA polymerase I e. eucaryotes only express one RNA polymerase

c. RNA polymerase II so rRNA is the basic one to make protein so it's I mRNA is the mediator between DNA and protein so it is II (in the middle) tRNA begins with T so it is III

The mitogen activated protein (MAP) kinase cascade is activated by which of the following? a. GPCRs that signal through Gs b. GPCRs that signal through Ras c. RTKs that signal through Ras d. RTKs that signal through PI-3 Kinase e. none of the above

c. RTKs that signal through Ras

during the g protein activation cycle, a ligand bound gpcr behaves like which of the following? a. a protein kinase b. a protein phosphatase c. a guaine nucleotide exchange factor d. a gtpase activating factor e. a nuclear localization signal

c. a guanine nucleotide exhcnage factor

28. The characteristic, biconcave shape of red blood cells is maintained by which of the following? a. unusually high cholesterol content b. a network of lipid rafts 28. The characteristic, biconcave shape of red blood cells is maintained by which of the following? a. unusually high cholesterol content b. a network of lipid rafts c. a network of protein filaments including spectrin d. a dense glycocalyx e. all of the above d. a dense glycocalyx e. all of the above q

c. a network of protein filaments including spectrin

signaling through a g protein coupled receptor most often results in which of the following a. reorganization of the cystosekleton b. calcium mobilization c, activation of a membrane associated enzyme d. alteration in gene expression

c. activation of a membrane associated enzyme

Signaling through a G-protein coupled receptor most often results in which of the following? a. reorganization of the cytoskeleton b. calcium mobilization c. activation of a membrane-associated enzyme d. alteration in gene expression e. none of the above

c. activation of a membrane-associated enzyme

growth factors signal through which of the following kinases a pka b. pkc c. akt kinase d. cam kinase 2 e. pi3 kinase

c. akt kinase

n type glycoylation involves the attachment of pre formed 14 residue carbohydrates to which of the following a. an asparate residue in the luminal domain - inside the er b. an asparate residue in the cytosolic domain c. an asparagine residue in the luminal domain - inside the er d. an asparagine residue in the cytosolic domain e. a glutamine residue in the luminal domain - inside the er

c. an asparagine residue in the luminal domain - inside the er

which of the following proteins is concentrated at the leading edge of a motile cell a. mysoin I b. myosin II c. arps d. formins e. all are concentrated at the leading edge

c. arps

g protein receptor kinases phosphorylate gpcrs at multiple sites marking them for desensitization. which of the following proteins binds to phosphorylated gprcs resulting in receptor densitization a. adaptin b. receptin c. arrestin d. sequestin e. inactin

c. arrestin

Depolymerization of microtubules occurs most rapidly ... a. at the (+) end, when tubulin dimer is below the critical concentration b. at the (+) end, when tubulin dimer is above the critical concentration c. at the (-) end, when tubulin dimer is below the critical concentration d. at the (-) end, when tubulin dimer is above the critical concentration

c. at the (-) end, when tubulin dimer is below the critical concentration

how is vesicular fusion powered a. atp exchange drives the formation of snare complex b. atp hydrolysis drives the formation of snare complex c. atp hydrolysis drives the dissociation of snare complex d. gtp hydrolysis drives the dissociation of snare complexes e. all of the above

c. atp drives the dissociation of snare complexes

during myosin movement alond an actin filament which event causes release of the head domain from the actin filament a. hydrolysis of atp b. hydrolysis of gtp c. binding of atp d. dissociation of adp e. dissociation of pi

c. binding of atp

During M phase, anaphase promoting complex (APC) is activated by ... a. proteolytic cleavage by separase b. polyubiquination c. binding of cdc20 d. dephosphorylation by cdc25 e. dissociation of p21

c. binding of cdc20

Activation of protein kinase A (PKA) does NOT involve which of the following events? a. dissociation of the alpha subunit of Gs from the beta-gamma subunit b. activation of adenylyl cyclase c. binding of cyclic AMP to the catalytic subunit of PKA d. dissociation of the regulatory subunit from the catalytic subunits of PKA e. exchange of GTP for GDP bound to Gs

c. binding of cyclic AMP to the catalytic subunit of PKA

What is the role of the troponin complex in striated muscle contraction? a. transmits action potentials to myofibrils b. opens calcium channels on the sarcoplasmic reticulum c. binds calcium and releases topomyosin d. activates myosin light chain kinase e. blocks myosin binding sites on actin filaments

c. binds calcium and releases topomyosin

Which of the following is FALSE regarding tubulin dimers? a. they are composed of alpha and beta subunits b. both the alpha and beta subunits bind GTP c. both subunits are capable of GTP hydrolysis d. the beta subunit is always exposed at the plus end of the microtubule e. all of the above are true regarding tubulin dimers

c. both subunits are capable of GTP hydrolysis

most g protein coupled receptors encoded in the human genome signal through which of the following intracellular messengers a. ip3 b. cgmp c. camp d. diacylgyecerol e. calcium

c. camp

Which of the following microtubule-associated proteins (MAPs) binds to and destabilizes the GTP Cap region of microtubules? a. MAP2 b. Tau c. catastrophe factor (kinesin 13) d. Taxol e. X-MAP215

c. catastrophe factor (kinesin 13)

the maturation promoting factor present in the cytoplasm of fetilized xenopus oocytes is which of the following proteins a. cyclin b b. cyclin m c. cdk1 d. cdc25 e. cdc6

c. cdk1

receptor mediated endocytosis invovles which of the following coated vesicles a. cop i vesicles b. retromer vesicles c. clathrin coated vesciles d. caveoli e. multivesicular bodies

c. clathrin coated vesciels

All of the following proteins are phosphorylated by M-Cdk, except ... a lamins b. cdc25 c. cohesins d. APC e. all are phosphorylated by M-Cdk

c. cohesins

For myosin motors, which event occurs immediately before the "power stroke"? a. hydrolysis of GTP b. hydrolysis of ATP c. dissociation of ADP d. exchange of ADP for ATP e. dissociation of Pi

c. dissociation of ADP

when a cell displays the delat ligand ont he plasma membrane what is this cell syaing to the adjacent cells a. dont come any closer b. dont differentiate c. dont become a neuron d. dont become an epithelial e. just dont

c. dont become a neuron

the minus end directed motor proteins that pull the spindle poles toward the membrane is called.. a. myosin I b. myosin II c. dynein d. Kinesin 5

c. dynein

14. In procaryotes, all amino acyl tRNAs that enter the A-site of the ribosome are accompanied by which of the following? a. messenger RNA b. ATP c. elongation factor Tu (EF-Tu) d. elongation factor G e. t-RNAs do not enter the A-site

c. elongation factor Tu (EF-Tu)

during kinesin movement along a microtubule which event casues the neck linkeer to zipper onto the head domains a. hydrolysis of atp b. dissociation of pi c. exchange of adp for atp d. hydrolysis of gtp e. exchange of gdp for gtp

c. exchange of adp for atp

the carbohydrate moieties of most integral membrane glycoproteins are usually found on extracellular domains. why is this so? a. carohydrates are only found in the extracellular space b. glycosylating enzymes are only found in the extracellular space c.glycosylatinf enzymes are only found in the er and Golgi d. glycosylating enzymes are only found in the cytosole. e. gygoside hydrolases remove the cytosolic carbohydrates from membrane proteins

c. glycosylating enzymes are only found in the er and Golgi

the carbohydrate moeitites of most integral membrane glycoproteins are usually found on the extracellular domains. Why? a. carbohydrates are only found in the extracellular space b. glycosylating enzymes are only found in the extracellular space c. glycosylating enzymes are only found in the Golgi and er d. gylgoside hydrolyases remove the cytosolic carbohydrates from the membrane proteins

c. glycosylating enzymes are only found in the golgi and er

which of the followinf ligands does not signal through intracelluar receptors a. thyroxine b. viatmin d3 c. growth hormone d. cortisol

c. groweth hormone

nittric oxide directly activates which of the following target proteins a. protein kinase a b. breb c. guanyly cyclase d. phospodiesterase e. adenyly cyclase

c. guanylyl cyclase

45. Which of following modifications would result in increased membrane fluidity? a. increased cholesterol content b. increased chain length of the fatty acid tails c. increased unsaturation of fatty acid tails d. increased protein content e. all of the above

c. increased unsaturation of fatty acid tails

activation of phosphlipase c beta results in the production of 2 signaling a. ionsitol 3 4 5 triphosphate b. inositol 2 4 5 triphoshate c. inositol 1 4 5 triphosphate d. diacylgylerol

c. insitol 1 4 5 triphophate

which of the follwing cytoskeletal components derives stength from coiled coil domains between dimeric subunits a. microtubules b. actin c. intermediate filament s d. all of the above

c. intermediate filament s

Which of the following cytoskeletal components derives strength from coiled-coil domains between dimeric subunits? a. microtubules b. actin c. intermediate filaments d. all of the above

c. intermediate filaments

Why is the human papilloma virus (HPV) is carcinogenic? a. it encodes the src oncogene b. it encodes the ras oncogene c. it encodes inhibitors of RB and P53 d. it encodes mutant forms of RB and P53 e. none of the above

c. it encodes inhibitors of RB and P53f

which of the following is not a serine threonine kinase a. protein kinase a b. weel kinase c. janus kinase 1 d. calcium calmodulin kinase 1 e. all of the above

c. janus kinase 1

which of the following events occurs during signaling through cytokine receptors a. the ras onogene activates thre mapk cascade b. a gene regulatory protein is produced by selective proteoplysis c. janus kinases phopsphorylate stat proteins d. cyclic gmp is hydrolyzes to 5' gmp

c. janus kinases phosporylate stat proteins

removal of the centrioles from a eukaryotic cell would result in which of the following a. disruption of actin cytockeleton b. disruption of microtubule cytockeleton c. loss of cilia d. necrosis e. apoptosis

c. loss of cilia

acetylcholine opens potassium channels on cardiac myocytes through the activation of the betaY complex. which of the following terms best describes the acetylcholine receptor that mediates this effect? a. second messenger gated ion channels b. nuclear receptor c. metabotrophic acetylcholine receptor d. ionotropic acetylcholine e. ligand gated ion channel

c. metobotropic acetylcholine receptor

which of the following statement is false a. a microtubule grow fastest from the plus end b. microtubule are composed of 13 protofilaments c. microtubules undergo catastrophe during which they fray at the minus end d. microtubules are often stabilized plus end capping proteins e. all of the above are true

c. microtubules undergo catastrophe during ewhich they frey at the minus end

which of the following is not composed of actin filaments a. microvilli of epithelial cells b. contractile ring c. neuronal axon d. lamellipodia e. stress fibeers

c. neuronal axon

which of the following is phosphorylated by the m cdk complex a. p53 b. securin c. nuclear lamin b d. p21 e. all of the above

c. nuclear lamin b

S-Cdk complex promotes DNA replication by phosphorylating which of the following? a. M-Cdk b. cdc6 c. origin of replication complex d. p21 e. none of the above

c. origin of replication complex

receptor tryosine kinase that signal through pi 3 kinases create binding sites on the plasma membrane for the recruitment and activation of downstrean kinases that contain which of the following a. ptb domains b. atp binding domains c. pleckstrin homology (ph) domains d. src homology 2 (SH2) domains e. src homology 3 (SH3) domains

c. pleckstrin homology domains

37. The membrane potential of an excitable membrane is primarily determined by which of the following proteins/complexes? a. sodium-potassium ATPase b. voltage gated sodium channels c. potassium leak channels d. ABC pump e. Ran GTPase

c. potassium leak channels

The anti-apoptotic protein, Bcl2, prevents apoptosis by ... a. binding to cytochrome C b. inactivating caspases c. preventing the aggregation of Bax & Bak d. promoting the expression of survival genes e. none of the above

c. preventing the aggregation of Bax & Bak

Breakdown of the nuclear envelop occurs during which phase of mitosis? a. prophase b. anaphase c. prometaphase d. telophase e. metaphase

c. prometaphase

when vesicles are delivered to the target membrane they are recognized and captured by tethering proteins on the target membrane. to which of the following vesicular proteins do tetherinf proteins bind a. clathrin b. dynamin c. rabs d. v snares e. none of the above

c. rabs

which gtpases is responsible for the release of clathrin coated vesicles from the source membrane a. ras gtpase b. rac gtpase c. ran gtpase d. rab gtpase e. dynamin

c. ran gtpase

which of the following small gtpases plays a key role in the mitogen activated protein pathway a. rac b. rab c. ras d. raf e. ran

c. ras

mitogens promote entry into cell cycle by inactivating which of the following proteins a. cdc20 b. p53 c. rb d. cyclin d e. apc

c. rb

how are receptor tryosine kinases activated a. binding of ligand b. binding of g protein c. receptor dimerization d. recruitment of solubule protein kinases

c. receptor dimerization

phosphorylation of tyrosine residues on receptor tyrosine kinases results in which of the following events a. receptor dimerization b. nuclear translocation of the receptor c. recruitment of signaling proteins to the plasma membrane d. accumulation of a soluble messenger in the cytoplasm e. none of the above

c. recruitment of signaling proteins to the plasma membrane

Phosphorylation of the Rb protein by G1-Cdk promotes entry into S phase by ... a. inactivation of p21 resulting in disinhibition of S-Cdk b. phosphorylation of Rb protein does not promote the G1-S phase transition c. releasing transcription factor E2F resulting in biosynthesis of S phase proteins d. activation of G1-Cdk, which phosphorylates the E2F protein e. binding to and inhibition of Cdh1-APC

c. releasing transcription factor E2F resulting in biosynthesis of S phase proteins

complete the following sentence. during the processing of the plasma membrane proteins ' a domain that is cytosolic at the er level a. is luckier than one that is not b. becomes extracellular c. remains cytosolic at the plasma membrane d. is glycoslated in the golgi complex e. is usually removed by a signal peptidase

c. remains cytosolic at the plasma membrane

what is the smallest contractile unit in striateed muscle cells a. sarcophagus b. sarcoplasmic reticulum c. sarcomere d. sarcaster e. myosome

c. sarcomere

during the formation of clathrin coated vesicles what happens immediately after vesicle release a. atp hydrolysis b. gtp hydrolysis c. spontaneous dissociation of coat portiens d. dynamin beceoms active e. rabs binds to specific proteins on the plasma membrane

c. spontaneous dissociation of coat proteins

In the tubulin heterodimer, the β-tubulin molecule provides ... a. the exchangeable ATP binding site b. the non-hydrolyzable ATP binding site c. the exchangeable GTP binding site d. the non-exchangeable GTP binding site

c. the exchangeable GTP binding site

in the tublun heterodimeer the beta tubulin molecule provides which of the following a. the exchangeable atp binding site b. the non hydrolyzable gtp binding sites c. the exchangeable gtp binding site d. the non exchangeable gtp binding site

c. the exchangeable gtp binding site

what is a dynamin a. a component of the dynein motor complex b. a protein that destablizies microtubules c. the gtpase that promotes vesicle releases d. an actin binding protein e. the receptor that detects ethylene during fruit ripening

c. the gtpase that promotes vescile release

During cytokine signaling through the JAK-STAT pathway, how are STAT proteins phosphorylated? a. very carefully b. they autophosphorylate c. they are phosphorylated by the JAKs d. they are phosphorylated by the cytokine receptor kinases e. STATs are NOT phosphorylated during cytokine signaling

c. they are phosphorylated by the JAKs

during cytokine signaling through the jak stat pathway how are stat proteins phosphorylated a. from gtp b. they autophosporylate c. they are phosporylated by the jaks d. they are phosphoylated by the cytokine receptor kinases e. stats are not phosporylated during cytokine signaling

c. they are phosphorylated by the jaks

how does the notch receptor signal to the nucleus a. through the jak stat pathway b. through the pka pathway c. through a proteolytic fragments d. through map kinase e. none of the aboce

c. through a proteeolytic fragment

At the anaphase checkpoint, which of the following events must occur for mitosis to proceed? a. inactivation of Rb b. dephosphorylation of cdc25 c. ubiquination of cyclin B by anaphase promoting complex (APC) d. phosphorylation of M-Cdk e. none of the above

c. ubiquination of cyclin B by anaphase promoting complex (APC)

when does catastrophe occur a. when atp levels are exhausted b. when microtubules contact the plasma membrane c. when the microtubule looses it gtp cap d. when the gtp bound form of tubulin dimer falls below the critical concentration e. when the microtubule reaches a certain age

c. when the microtubule looses it gtp cap

33. During RNA splicing, the spliceosome generates an intermediate structure called the "lariat', which includes the intron sequence that is being removed from the mRNA. How is the lariat formed? a. the 2' hydroxyl of a conserved guanosine residue attacks the 5' splice site. b. the 3' hydroxyl of a conserved guanosine residue attacks the 5' splice site. c. the 3' hydroxyl of a conserved adenosine residue attacks the 3' splice site. d. the 2' hydroxyl of a conserved adenosine residue attacks the 5' splice site. e. the 3' hydroxyl of a conserved adenosine residue attacks the 5' splice site.

d. the 2' hydroxyl of a conserved adenosine residue attacks the 5' splice site. basically there were 5 girls in the spLice girls... they were OH TWO cool

35. What are Okazaki fragments? a. the RNA primers used to synthesize the leading strand b. the RNA primers used to synthesize the lagging strand c. the DNA segments that comprise the leading strand d. the DNA segments that comprise the lagging strand e. none of the above

d. the DNA segments that comprise the lagging strand

Which of the following events occurs during TGFβ signaling? a. the Ras oncogene activates the MAPK cascade b. a gene regulatory protein is produced by selective proteolysis c. Janus kinases (JAKs) phosphorylate STAT proteins d. the Type 1 receptor phosphorylates Smad 2/3 e. β-catenin accumulates and enters the nucleus

d. the Type 1 receptor phosphorylates Smad 2/3

which of the following best describes the default destination for an unfolded protein with an n terminao mitochondrial signal sequence a. the outer membrane b. the inner mitochondrial membrane c. the intermembrane space d. the mitochondrial matrix e. all of the above

d. the mitochondrial matrix

which of the following best describes the default destination for an unfolded protein with an n-terminal mitochondrial signal sequence a. the outer mitochondrial membrane b. the inner mitochondrial membrane c. the intermembrane space d. the mitochondrial matrix e. none of the above

d. the mitochondrial matrix

what is the ultimate fate of apoptotic cell a. they aggergate in tissue to form scars b. they are processed to simple compounds by their own enzymes c. they remain quiescent until activation of g1 s cdk d. they are consumed by macrophages e. they emerge in a parallel universe as components of anti creatures

d. they are consumed by macrophages

during receptor mediated endocytosis clathrin formed vesicles containing the ligand receptor complexes fuse with sorting endosomes. what happens to the receptors a. they accumulate in the cytosol b. they are deegraded in lysosomes c. they are sent to the golgi complex for repair d. they are returned to the plasma membrane e. they burst into flames

d. they are returned to theplasma membrane

which of the following is true regarding most kinesin motor proteins a. they hydrolyze gtp and move toward the plus end of the microtubule b. they hydrolyze gtp and move toward the minus end of the microtubule c. they hydrolyze atp and move toward the minus end of the microtubule d. they hydrolyze atp and move towats the plus end of the microtubule e. they hyrdolyze atp and move toward the plus end of the actin filament

d. they hydrolyze atp and move toward the plus end of microtubule

what is the role of arrestins in g protein coupled receptor signaling. a. they prevent receptor dimerization b. they are guanine nucelotide exchange factors c. they are protein kinases that phosphorylate gpcrs d. they participate in receptor desensitization

d. they participate in receptor densitization

which of the following is false about n glycosylation process a. it occurs in the cytosol b. a pre formed 14 residue oligosaccharide is presented by the lipid carrier dolichol c. the oligosaccharide is transferred to the amide nitrogen of a asn residue d. transfer of the ribosome to ther er translocator e. inversion of the earths magnetic field

d. transfer of the ribosome to the er translocator

during translation of a er membrane protein, a signal recognition particle (SRP) binds to the er signal sequence and translation is arrested. which of the following events causes translation of this protein to continue a. phosphorylation of the srp b. binding of the complex to the srp receptor c. binding of molecular chaperones to the complex d. transfer of the ribosome to the er transloactor protein e. inversion of the earth's magnetic field

d. transfer to the ribosomes to the er translocator protein

26. During the transport cycle for the sodium-potassium ATPase, which event occurs immediately after dephosphorylation of the critical aspartate residue? a. transport of 3 sodium ions from the cytosolic compartment to the extracellular compartment. b. transport of 3 sodium ions from the extracellular compartment to the cytosolic compartment c. transport of 2 sodium ions from the extracellular compartment to the cytosolic compartment d. transport of 2 potassium ions from the extracellular compartment to the cytosolic compartment e. transport of 3 potassium ions from the extracellular compartment to the cytosolic compartment

d. transport of 2 potassium ions from the extracellular compartment to the cytosolic compartment

which structure is responsible for transmitting the action potential to calcium storage sites in striated muscles cells a. a sarcoplasmic reticulum b. intermediate filaments c. actin filaments d. transverse tubule e. desomosomes

d. transverse tubule

calcium homesotasis is mainatined in part through the action of calicum atpases. these p type pumps can be found on which of the following membrane s a.plasma b. mitochondrial inner membrane c. smooth er d. two of the above e. all of the above

d. two of the above A AND C

When does "catastrophe" occur? a. when microtubules reach a certain age b. when microtubules contact the plasma membrane c. when ATP levels are exhausted d. when the microtubules loses it's GTP cap e. when the GTP-bound form of tubulin dimer falls below the critical concentration

d. when the microtubules loses it's GTP cap

Which of following modifications would result in increased membrane fluidity?

decreased cholesterol content decreased chain length of the fatty acid tails increased amount of unsaturation of fatty acid tails decreased sphingomyelin

A loss of function mutation of the p53 gene would result in ...

decreased p21 expression leading to unregulated entry into S phase

When does treadmilling of actin filaments occur? a. when the rate of ATP hydrolysis exceeds the rate of actin polymerization b. when the rates of actin polymerization at the plus (+) and minus (-) ends of the actin filament are equal. c. when the rate of actin polymerization at the plus (+) end of the actin filament is equal to the rate of actin depolymerization at the minus (-) end of the actin filament. d. when the rates of actin depolymerization at the plus (+) and minus (-) ends of the actin filament are equal. e. when myosin motors are pulling against actin filaments.

c. when the rate of actin polymerization at the plus (+) end of the actin filament is equal to the rate of actin depolymerization at the minus (-) end of the actin filament.

when does treadmilling of actin filaments occur a. when the rate of atp hydrolysis exceeds the rate of actin polyermization b. when the rates of actin polyermization at the plus and minus ends of the actin filament are equal c. when thte rate of actin polymerization at the plus end of the actin filament is equal to the rate of actin depolymerization at the the minus end of the actin filament d. when the rates of actin depolymerization at the plus and minus ends of the actin filament are equals e. when myosin motors are pulling against actin filaments

c. when the rate of actin polymerization t the plus eend of the

which of the following structures is responsible for nucleating mincrotubule formation a. arp complexes b. all of the above c. y tublulin rind complexes d. formin e. none of the aboce

c. y tubulin ring complexes

In the lab, you have cultured cells that express a trimeric G protein of the Gi family. Which of the following best describes the expected result of pertussis toxin treatment on these cells?

cAMP levels go up

In the lab, you have cultured cells that express a trimeric G protein of the Gs family. Which of the following best describes the expected result of cholera toxin treatment on these cells?

cAMP levels go up

In the lab, you have cultured cells that express a trimeric G protein of the Gs family. Which of the following best describes the expected results of cholera toxin treatment of these cells

cAMP levels go up

With a culture of cells that express trimeric G protein of the Gs family, what described result of cholera toxin on cells? -cAMP levels go down -cAMP levels go up -cGMP levels go up -IP3 levels go down -IP3 levels go up

cAMP levels go up

Which of the following best describes the events that occur after photoisomerization of 110cis retinal in rod photoreceptor cell?

cGMP level decrease, Na+ channels close, the cell hyperpolarize, and glutamate release decreases.

after photoactivation of rhodopsin in the retina

cGMP levels decrease sodium channels close the cell is hyperpolarized

What events occur after photoisomerization of 11-cis retinal in rod photoreceptor cells?

cGMP levels decrease, Na+ channels close, the cell hyperpolarizes and glutamate release decreases

Which of the following best describes the events that occur after photoisomerization of 11-cis retinal in rod cells?

cGMP levels decrease, Na+ channels close, the cell hyperpolarizes and glutamate release decreases

In the retina, photoisomerization of 11-cis retinal activated rhodopsin, which then activates the trimeric G protein, Gt (transductin_. what membrane associated enzyme is activated by Gt? -guanylyl cyclase -anenylyl cyclase -phospholipase C -cGMP phosphodiesterase -cAMP phosphodiesterase

cGMP phosphodiesterase

Photoisomerization of 11-cis retinal activates rhodopsin, which, in turn, activates the trimeric G-protein, Gt (transducin). Which of the following membrane associated enzymes is activated by Gt?

cGMP phosphodiesterase

The blockbuster drug "Viagra" is an inhibitor of which of the following enzymes?

cGMP phosphodiesterase

Viagra and related drugs affect the nitric oxide signaling pathway by acting on which of the following signaling molecules?

cGMP phosphodiesterase

In rod cells of the vertebrate retina, photoisomerization of 11-cis-retinal activated rhodopsin which, in turn, activates the trimeric G-proteins, Gt. Which of the following membrane -associated enzymes is activated by the alpha subunit of Gt.

cGMP phphosphodiesterase

Drugs like Viagra work by inhibiting which proteins? -sodium potassium ATPase -adenylyl cyclase -guanylyl cyclase -cAMP specific phosphodiesterase -cGMP specific phosphodiesterase

cGMP specific phosphodiesterase

Drug like Viagra work by inhibiting which of the following enzyme

cGMP-specific phosphodiesterase

Which of the following CAMs are components of adherens junctions and desmosomes?

cadherins

Which of these transporters would you expect to find in the membrane of the endoplasmic reticulum?

calcium ATPase

During vesicle formation, adaptins bind FIRST to which of the following proteins?

cargo receptors

myelination of axons in the peripheral nervous system

carried out by Schwann cells insulates the axons to reduce current leakage increases the speed of action potential propagation through saltatory conduction conserves energy because the active excitations are restricted to the nodes of Ranvier

The proteases that dismantle the cell during apoptosis are called

caspases

The low pH inside endosomes

causes internalized receptors to release their cargo

Trancytosis is primarily accomplished by which transport system?

caveoli

phosphorylated by M-Cdk?

cdc20 lamins cdc25

At the M-phase checkpoint, which of the following proteins is the phosphates that removes the inhibitory phosphate group for M-cdk complex?

cdc25

Which of the following refers to the phosphatase that activates M-Cdk to initiate M-phase?

cdc25

S-Cdk complex initiates DNA replication by phosphorylating which of the following?

cdc6

Which of the following proteins is required to sustain G1 phase?

cdh1

Which of the following proteins replaces cdc20 to maintain anaphase promoting complex activity during G1 phase

cdh1

If a cell is deprived of proliferation signals for long enough, it can enter a specialized state (Go) in which

cell division is suspended for an indefinite period of time

Which of the following is NOT a microtubule organizing center (MOC)?

centriole

not an MOC

centriole

microtubule organizing centers

centrosome, basal body, spindle pole

Which of the following proteins is most highly expressed during the unfolded protein response?

chaperone proteins

Which type of protein binds to improperly folded or improperly assembled proteins in the ER holding them there until proper folding occurs?

chaperone proteins

Many inhibitory neurotransmitters hyperpolarize the postsynaptic membrane by opening ...

chloride channels

What protein can assemble into a basket-like network that gives budding vesicles their shape?

clathrin

the role of the lysosome

clean-up recycling disposal of macromolecules

An antiporter mediates, which of the following processes?

co-transport a solute molecule against its concentration gradient and an ion along its concentration gradient in opposite direction across the plasma membrane

An antiporter mediates which of the following processes?

co-transport of a solute molecule agains t its concentration gradient and an ion along its concentration gradient in opposite directions across the plasma membrane

An SYMPORTER mediates which of the following processes?

co-transport of a solute molecule against its concentration gradient and an ion along its concentration gradient in the same direction across the plasma membrane

Which of the following proteins promotes the depolymerization of actn filament near the lamellipodium?

cofilin

Which of the following refers to the proteins that are cleaved by separase to release sister chromatids at anaphase?

cohesins

The spiral association of two amphipathic alpha helices is called a ...

coiled-coil domain

glycosaminoglycans

components of proteoglycans abundant in the extracellular space most are rich in N-acetylglucosamine

tubulin dimers

composed of alpha and beta subunits both alpha and beta bind GTP only beta subunit can hydrolyze its bound nucleotide beta subunit is always exposed to the plus end of the microtubule

the ribosome

composed of two ribonucleoprotien complexes 2/3rds of mass of ribosome is RNA most of the catalytic functions of the ribosome are carried out by RNA it assembles only after mRNA is bound to the small subunit

Which of the following refers to the SMC protein complex that gathers and organizes newly replicated DNA into chromosomes ?

condensin

The SMC protein complexes that gather and organize DNA strands into chromosomes are called ...

condensins

What is the term for the SMC protein complexes that gather and pack newly replicated DNA into chromosomes?

condensins

Which of the following refers to the SMC protein complex that gathers and organizes newly replicated DNA into chromosomes ?

condensins

Which of the following optical techniques employs a pinhole to restrict light detection to photons originating from the focal plane?

confocal

Which of the following microscopic techniques supports three dimensional reconstruction from optical sections obtained from a fluorescent specimen?

confocal laser scanning microscopy

confocal microscopy

36. An SYMPORTER mediates which of the following processes? a. co-transport of a solute molecule against its concentration gradient, and an ion along its concentration gradient in the same direction across the plasma membrane b. co-transport of a solute molecule against its concentration gradient, and an ion along its concentration gradient in opposite directions across the plasma membrane c. co-transport of a solute molecule along its concentration gradient, and an ion against its concentration gradient in the same direction across the plasma membrane d. co-transport of a solute molecule along its concentration gradient, and an ion against its concentration gradient in opposite directions across the plasma membrane

a. co-transport of a solute molecule against its concentration gradient, and an ion along its concentration gradient in the same direction across the plasma membrane

which of the following coat proteins is/are responsible for the formation of transport vesicles at the er membrane a. cop proteins b. clathrin c. dynamin d. rab gtpases e. vsnares

a. cop proteins

at the metaphase anaphase transition which of the following proteins is ubiquinated by apc a. cyclin b b. cdc20 c. separase d. cohesions e. none of the above

a. cyclin b

Which of the following is in correct order of decreasing bond strength in AQUEOUS MEDIUM?

covalent bond > ionic bond > hydrogen bond > van der Waals

MPF activity is attributed to which of the following proteins? a. cyclin dependent kinase 1 (Cdk1) b. cyclin dependent kinase 2 (Cdk2) c. cyclin A d. cyclin B e. MPF is not a protein

a. cyclin dependent kinase 1 (Cdk1)

clathrin coated vesicles usually transport their content to which of the following a. endosome b. cis golgi network c. plasma membrane d. nucleus e. endoplasmic reticulum

a. endosomes

during receptor mediated endocytosis the contents of clathrin coaed vesicles are sorted in which compartment a. endosomes b. lysosomes c. trans golgu complex d. cis Golgi complex e. none of the above

a. endosomes

glycoproteins that receieve 6- phosphate tag during transmit through the golgi complex are package into vesciles and shipped to which of the following compartment a. endosome b. the extracelluar compartment c. the cytoplasm

a. endosomes

which of the following messenger molecules mediates the ripening of fruit a. ethylen b. methylene c. ethane d. methane e. acetylene

a. ethylene

for kinesin motor, which event occurs immediately before the power stroke a. exchange of adp for atp d. dissociation of pi c. hydrolysis of gtp d. hydrolysis of atp e. dissociation of adp

a. exhange of adp for atp

During cell signaling through G-protein coupled receptors, what event causes dissociation of the alpha subunit from the beta-gamma subunit? a. exchange of bound gdp for gtp on the alpha subunit b. exchange of bound gdp for gtp on the beta subunit c. phosphorylation of an essential tyrosine residue on the alpha subunit d. phosphorylation of an essential tyrosine residue on the beta gamm subunit e. phosphorykation of an essential serine residue on the alpha subunit

a. exhcnage of bound gdp for gtp on the alpha subunit

which of the following protein complexes is capable of nucleating actin filaments a. formin dimers b. gamma tubulin ring complexes c. centrioles d. cofilin e. none are capable of nulceating actin filaments

a. formin dimers

which of the following initiates actin polymerization a. formins b. gamma tubulin ring complexes c. centrioles d. microtubule fragments

a. formins

which of the following is the largest group of cell signaling proteins in eukaryotes a. g protein coupled receptor b. small gtpases c. receptor tyrosine kinases d. nuclear receptors e. ion channels

a. g protein coupled receptors

during which phase of cell cycle does most cell growth occur a. g1 phase b. s phase c. g2 phase d. m phase e. cell growth occurs throughout cell cycle

a. g1 phase

application of a gpcr agonist to cultured cells increases phospolipase c beta activity. this affect is not blocked by high concentration of pertussis toxin. therefore this gpcr is probably singaling through which of the following trimeric g protein a. gq b. gt c. gi d. gs e. go

a. gq

cholera toxin disrupts cell biochemistry by colvalently modifying the alpha subunit of which of the followinf trimeric g proteins a. gs b. gi c. go d. gq

a. gs

in the laboratory, you have shown that activation of a novel gpcr increases phospholipase c actvity, and that this effect is blocked by pertussis toxin. this gpcr is probably signaling through which of the following g protein

a. gs b. gi c. go d. gt (transducin) e. ras

what is the source of the energy required for tranport of proteins through the nuclear pore complex a. gtp hydrolysis b. atp hydrolysis c. sodium ion gradient d. calcium ion gradient e. energy is not required to transport proteeeins through the npc

a. gtp hydrolysis

during receptor mediated activation of a trimeric g protein which of the following events terminates the signal a. gtp hydrolysis by the alpha subunit b. gtp exchange by the alpha subunit c. gtp hydrolysis by the beta gamma complex d. gtp exchange by the beta gamma complex e. internalization of the receptor

a. gtp hydrolysis by the alpha subunit

in early anaphase APC is activated by cdc 20 during G1. when cdc 20 is depleasted APC activity is maintained by which of the following proteins a. hct 1 b. gl cdk c. p 53 d. rb e. p21

a. hct 1

22. Which of the following enzymes is responsible for unwinding the DNA double helix during DNA replication? a. helicase b. DNA polymerase c. DNA ligase d. primase e. none of the above

a. helicase

Which of the following mechanisms is capable of repairing double strand breaks in DNA without loss of sequence information? a. homologous recombination b. non-homologous end joining c. DNA mismatch repair d. gene conversion e. reverse transcription

a. homologous recombination

Most kinesin motors .. . a. hydrolyze ATP and "walk" toward the plus (+) end of microtubules. b. hydrolyze GTP and "walk" toward the plus (+) end of microtubules. c. hydrolyze ATP and "walk" toward the minus (-) end of microtubules. d. hydrolyze GTP and "walk" toward the minus (-) end of microtubules.

a. hydrolyze ATP and "walk" toward the plus (+) end of microtubules.

most kinesin motor a. hydrolyze atp and walk toward the plus + end of microtubules b. hydrolyze gtp and walk toward the plus end of microtubules c. hydrolyze atp and walk toward the minus end of microtubules d. hydrolyze gtp and walk toward the minus end of microtubules

a. hydrolyze atp and walk toward the plus end of microtubules

phospholipse c beta activation leads to the production of at least 2 signaling molecules IP3 and diacylglyceerol. what is the function of IP3 a. it activates receptors on the er membrane, resulting in the release of calcium into the cytocol b. it recruits protein kinase c to the plasma membrane c. it activated adenylyl cyclase d. it activated guanylyl cyclase e. none of the above

a. it activates receptors on the er membrane resulting in the release of calcium into the cytosol

which of the following is flase regarding protein kinases a a. it is activated by the binding of camp to the catalytic subunit b. it phosphorylates and activates the creb protein c. it mediates the effects of g protein coupled receptors that signal through gs d. it is a serine-threonine kinase e. all of the above

a. it is activated by the binding of camp to the catalytic subunit

what is the role of tropomyosin in striated muscle contraction a. it is the minus end capping protein in striateed muscle b. it transmits action potentials to myofibrils c. it opens calcium channels on the sarcoplasmic reticulum d. it blocks myosin binding sites on actin filaments e. it binds calcium and exposes myosin binding sites on actin filaments

a. it is the minus end capping protein in striated muscle

How does the cancer drug Taxol inhibit cell division? a. it stabilizes microtubules b. it destabilizes microtubules c. it causes actin polymerization in the wrong direction d. it initiates apoptosis e. it disrupts DNA

a. it stabilizes microtubules

how does the anit cancer drug taxol inhibit cell division a. it stabilizes microtubules b. it destabilies microtubules c. it causes microtubules polymerization in the wrong direction d it prevents microtubule polyermization e. it iniates apoptosis

a. it stabilizes microtubules

how does the anti cancer drug taxol inhibiy cell division a. it stabilizes microtuibules b. it destabilizes microtubules c. it causes actin polyermization in the wrong direction d. it initates apoptosis e. it disrupts dna

a. it stablizes microtublues

Which of the following is an intermediate filament protein found exclusively in epithelial cells? a. keratin b. collagen c. vimentin d. lamin A e. none of the above

a. keratin

which of the following intermediate filaments is the cytoskeletal component of desmosomes between epithelial cells a. keratins b. vimentin c. neurofilaments d. nuclear lamins e. none of the above

a. keratins

which of the following signal sequence identifies a protein for retention in the endoplasmic recticulum a. lys-asp-glu=leu=co2h b. ser-lys-leeu-co2h c. h3n-met-met-ser-leeu-leu0leu-val-gly-ile-leu-phe-trp-ala d.pro-pro-lys-lys-lys-arg-val e. none of the above

a. lys-asp-glu-leu-co2h

the phenomenon of dynamic instability is displayed by which of the following cytoskeletal components a. microtubules b. actin filaments c. intermediate filaments d. all of thee above e. none of the above

a. microtubules

growth factors increase protein synthesis and decrease protein degradation by activating which of the following a. mtor b. cdh1 c.c cdc20 d. p53 e. myc

a. mtor

which of the following is an intermiediate filament that is found in all eukaryotic cells a. nuclear lamins b. keratins c. neurofilaments d. microfilaments e. all of the above

a. nuclear lamins

Most procaspases are activated by ... a. other caspases b. death signals c. kinases d. cytochrome C e. none of the above

a. other caspases

during embryonic development, the fate of uncomminted cells is often determined by their loaction along an extracellular gradient of a diffusable morphogen. this is an example od which of the following signaling strategies a. paracrine signaling b. contact dependent signaling c. synaptic signaling d. endocrine signaling e. none of the above

a. paracrine signaling

17. Which phospholipid is negatively charged at neutral pH? a. phosphatidyl serine b. phosphatidyl choline c. phosphatidyl ethanolamine d. sphingomyelin e. none of the above

a. phosphatidyl serine

which of the following events prevents a second round of dna replication a. phosphorylation of orc b. phosphorylation of cdc25 c. ubiquination of cyclin b d. ubiquination of cdc6 e, none of the above

a. phosphorylation of orc

complete the following sentence " most kinesins are ..... a. plus end directed microtubule motor proteins b. minus end directed microtubule motor proteins c. plus end directeed actin motor proteins d, minus end directed actin motor proteins e. inactive structural proteins

a. plus end directed microtubule motor proteins

40. The resting membrane potential of approximately -70 mV is due to the selective permeability of the plasma membrane to which of the following ions? a. potassium b. sodium c. chloride d. calcium e. lithium

a. potassium

during delta notch signaling a factor is generated in the targeet cell that enters the nucleus and alters gene expression. which of the following enzymes generates this factor a. protease b. a phosphatase c. protein kinase a d. protein kinase c e. phospholipase c beat

a. protease

capasases are ..... a. proteases b. phosphatases c. ubiquitin ligases d. scaffold proteins e. kinases

a. proteases

signal induced changes in the architecture of actin cytoskeleton are mediated by members of the rho family of small gtpases. which rho family member facilitates the formation of stress fibers a. rho b. ras c. rac d. rab5 e. cdc42

a. rho

the mitogen activated protein kinase cascade is activated by which of the following a. rtks that signal through ras b. gpcrs that signal through ras c. rtks that singal pi 3 d. gpcrs that singal through gs e. none of the above

a. rtks that signal through ras

the mitogen activated protein kinase cascade is activated by which of the following a. rtks that signal through ras b. rtks that signal through pi3 kinase c. gpcrs that signal through gs d. gpcrs that signal through ras

a. rtks that singal through ras

posttranslational processing secretory proteins is completed in which of the following compartments a. secretory vesicles b. early endosome c. er lumen d. cis golgi network e. trans golgi network

a. secretory vesciles

6. What are Sigma Factors? a. subunits of the RNA polymerase in bacteria b. components of the spliceosome c. components of the general transcription apparatus d. mRNA capping proteins e. none of the above

a. subunits of the RNA polymerase in bacteria

during g protein coupled receptor signaling, which protein serves as the guanine nucleotide exchange factor for the g alpha subunit a. the occupied gpcr b. phosphatidyl inositol c. the beta subunit d. the Y subunit

a. the occuiped gpcr

13. How do transposons move from one location in the DNA to another? a. they encode an enzyme that catalyzes the cut-and-paste reactions b. they rely on viral enzymes to catalyze the cut-and-paste reactions c. they use the DNA mismatch repair system d. they do so only during homologous recombination e. the mechanism is not known

a. they encode an enzyme that catalyzes the cut-and-paste reactions

which of the following is TRUE regarding most kinesin motor proteins a. they hydrolyze atp and move toward the plus end of the microtubule b. they hydrolyze atp and move toward the mius end of the microtubule c. they hydrolyze atp and move toward the plus end of the actin filament d. they hydrolyze gtp and move toward the plus end of the microtubule e. they hydrolyze gtp and moe toward the minus end of the microtubule

a. they hydrolyze atp and move toward the plus end of the microtubulue

Which structure is responsible for transmitting the action potential to calcium storage sites in striated muscle cells? a. transverse tubule b. sarcoplasmic retibulum c. intermediate filaments d. actin filaments e. desmosomes

a. transverse tubule

what structure is responsible for transmitting the action potential to calcium storage sites in striated muscles cells a. transverse tubule b. the lamellapodium c. sarcoplasmi reticulum d. myofibril e. actin cytoskeleton

a. transverse tubule

which of the following serves as the minus end capping protein of actin filaments in striateed muscle a. tropomodulin b. troponin c. tropomyosin d. capz e. none of the above

a. tropomodulin

Anaphase promoting complex (APC) is (a) a. ubiquitin ligase b. transcription factor c. protein kinase d. phosphoprotein phosphatase e. none of the above

a. ubiquitin ligase

which of the following kinases is responsbile for phosphorylation oand inactivation of mcdk a. wee 1 kinase b. map kinase c. akt kinase d. s cdk e. cdc25

a. wee 1 kinase

Which of the following structures is responsible for nucleating microtubule formation? a. γ-tubulin ring complexes b. formin dimers c. tubulin dimers d. microtubule-associated proteins (MAPs) e. none of the above

a. γ-tubulin ring complexes

which of the following is false about the n-glycosylation process a. it occurs in the cytosol b. a pre-formed 14 residue oligosaccharide is presented by the lipid carrier, dolichol c. the oligosaccharide is transferred to the amide nitrogen of a asn resiude d. the last 2 glucose residues are cleaved before export from the er e. all above are false

a.it occurs in the cytosol

Fluorescence microscopy is based on the ability of certain molecules to...

absorb light of a given wavelength and then eight light of a longer wavelength

In some cells, the catalytic subunit of protein kinase A (PKA) can enter the nucleus and alter gene expression by phosphorylating which of the following proteins?

cyclic AMP response element binding (CREB) protein

When a catalytic subunit of the cyclic AMP-dependent protein kinase enter the nucleus, it phosphorylate which of the following transcription factor.

cyclic AMP response element binding (CREB) protein

Which of the following transporters is incorrectly matched with the energy source that powers the transport process in the forward direction? a) bacteriorhodopsin & light b) flippases & ATP c) antiporter & potassium ion gradient d) F-type pump and pH gradient e) all of the above are correctly matched

antiporter & potassium ion gradient

collagens

are the most abundant proteins in the animal kingdom are formed from three alpha helical proteins bound in a coiled-coil subunits are encoded by at least 20 genes assembled into fibers in the extracellular space

You have isolated a temperature sensitive yeast mutant. When maintained at the restrictive temperature, all of the yeast cells are arrested at the "start" checkpoint (G1-S transition) due to a loss-of-function mutation of a single gene. Below are listed five proteins. Which one is most likely to be the protein responsible for the observed phenotype (i.e., arrest at G1-S transition)?

cyclin A

At the metaphase-anaphase transition, which of the following proteins is ubiquinated by APC?

cyclin B

In rapidly dividing cells, MPF activity was observed to oscillate, with peak levels occurring at the G2 - M transition). The oscillatory component of the MPF complex was later shown to be which of the following proteins?

cyclin B

17) Complete the following sentence. "Cytoplasmic dyneins are ..." a) dimeric, plus (+) end directed microtubule motor proteins b) dimeric, minus (-) end directed microtubule motor proteins c) trimeric, plus (+) end directed microtubule motor proteins d) trimeric, minus (-) end directed microtubule motor proteins e) components of the nuclear envelope

19) What process provides the force that propels the leading edge of a motile cell forward? a) tubulin dimer polymerization b) actin polymerization c) myosin I motors d) myosin II motors e) dynein motors

2) The effect of pertussis toxin treatment on trimeric G-protein signaling is due to which of the following covalent modifications? a) ubiquitination of the alpha subunit b) ADP ribosylation of the alpha subunit c) phosphorylation of the alpha subunit d) phosphorylation of the beta-gamma complex e) dephosphorylation of the beta-gamma complex

20) After release of the myosin head from an actin filament, which of the following events "cocks" the myosin head into the active conformation. a) binding of ATP b) ATP hydrolysis c) dissociation of ADP d) dissociation of Pi e) none of the above

24) Which of the following is phosphorylated by S-Cdk to initiate DNA synthesis during S-phase? a) DNA polymerase b) Cdc6 c) MPF d) ORC e) Helicase

25) Which of the following kinase-cyclin pairs is correctly matched? a) S Cdk & cyclin B b) G1-S Cdk & cyclin E c) M Cdk & cyclin C d) G1-Cdk & cyclin A e) All are correctly matched

26) Which of the following events occurs during prometaphase? a) DNA replication b) disintegration of the nuclear envelope c) ubiquination of cyclin B d) inactivation of APC e) formation of the contractile ring

27) Which of the following binds calcium ions and promotes skeletal muscle contraction? a) tropomodulin b) troponin complex c) tropomyosin d) calmodulin e) contractin

31) Which of the following is phosphorylated by S-Cdk to initiate DNA synthesis? a) DNA polymerase b) Cdc6 c) MPF d) ORC e) Helicase

31) Which of the following phosphorylates and inactivates the Wee1 kinase at the onset of M-phase? a) p53 b) M-Cdk complex c) S-Cdk complex d) APC e) cdc25

32) Which of the following refers to the protein complex that gathers and organizes newly replicated DNA into chromosomes? a) gatherin b) condensin c) cohesin d) compressin e) chromatin

33) Which of the following is phosphorylated by S-Cdk to initiate DNA synthesis a) DNA polymerase b) Cdc6 c) MPF d) ORC e) Helicase

cyclin B

MPF activity is attributed to which of the following proteins?

cyclin dependent kinase 1 (Cdk1)

Proteins that lack a sorting signal remain as permanent residents of which part of the eukaryotic cell?

cytosol

4) Which of the following best describes the events that occur after photoisomerization of 11-cis retinal in rod cells? a) cGMP levels increase, Na+ channels open, the cell depolarizes, and glutamate release increases b) cGMP levels decrease, Na+ channels close, the cell hyperpolarizes and glutamate release decreases c) cGMP levels increase, Na+ channels close, the cell depolarizes, and glutamate release increases d) cGMP levels decrease, Na+ channels close, the cell depolarizes, and glutamate release increases e) cGMP levels increase, Na+ channels close, the cell hyperpolarizes, and glutamate release decreases

4) Which of the following is NOT a microtubule organizing center (MOC)? a) centrosome b) centriole c) spindle pole d) basal body e) all of the above are MOCs

40) What is the energy source that drives chromosomal segregation during anaphase B? a) the electrochemical gradient across the plasma membrane b) ATP hydrolysis c) GTP hydrolysis d) catastrophic shortening of kinetochore microtubules e) the energy source is not known

40) What is the role of Hct1 in the cell cycle? a) it prevents initiation of S phase b) it binds to APC to promote G1 c) it inhibits P53 d) it is a component of the pre-initiation complex e) it is a transcription factor

) What is the role of tropomyosin in striated muscle contraction? a) it is the minus (-) end capping protein in striated muscle b) it transmits action potentials to myofibrils c) it opens calcium channels on the sarcoplasmic reticulum d) it blocks myosin binding sites on actin filaments e) it binds calcium and exposes myosin binding sites on actin filaments

48) Which of the following best describes the apical-to-basolateral order of occurrence of cell-cell junctions in an epithelial cell? a) tight junctions - desmosomes - adherens junctions - gap junctions b) tight junctions - adherens junctions - desmosomes - gap junctions c) tight junctions - adherens junctions - gap junctions - hemidesmosomes d) adherens junctions - tight junctions - gap junctions - hemidesmosomes e) adherens junctions - tight junctions - desmosomes - gap junctions

49) During apoptosis, how does cytochrome C get out of the mitochondrion? a) it leaves through channels formed by "BH3 only" proteins b) it leaves through channels formed by "BH123" proteins c) it aggregates to form clusters that are membrane permeable d) it binds to BH123 proteins and enters the cytosol e) it binds to Bcl2

5) Which of the following statements is FALSE regarding microtubules? a) microtubules are composed of 13 "protofilaments" b) microtubules grow fastest from the minus (-) end c) microtubules display the property of dynamic instability d) microtubules undergo "catastrophe", during which they fray at the plus (+) end e) all of the above are TRUE regarding microtubules

8) Janus kinases phosphorylate which of the following signal transduction proteins? a) CREB b) STATs c) IP3 d) MAP kinases e) none of the above

8) Which small GTPase might be activated during remodeling of the actin cytoskeleton? a) Rab d) Ram b) Rac e) dynamin c) Ran

All cell-matrix junctions include which of the following cell adhesion molecules? a) desmocollin d) classical cadherins b) integrin dimers e) non-classical cadherins c) claudin

Complete the following sentence. "Cytoplasmic dyneins are ..." a) dimeric, plus (+) end directed microtubule motor proteins b) dimeric, minus (-) end directed microtubule motor proteins c) trimeric, plus (+) end directed microtubule motor proteins d) trimeric, minus (-) end directed microtubule motor proteins e) components of the nuclear envelope

During apoptosis, how does cytochrome C get out of the mitochondrion? a) it leaves through channels formed by "BH3 only" proteins b) it leaves through channels formed by "BH123" proteins c) it aggregates to form clusters that are membrane permeable d) it binds to BH123 proteins and enters the cytosol e) it binds to Bcl2

During kinesin movement along a microtubule, what happens immediately after nucleotide exchange? a) the motor head releases the microtubule b) the neck linker "zippers" onto the leading head c) the trailing head dissociates d) the leading head binds tightly e) the leading head is thrust forward

How does cytochrome C initiate apoptosis? a) it directly activates executioner procaspases b) it promotes the aggregation of initiator procaspases c) it aggregates to form channels in the outer mitochondrial membrane d) it promotes the aggregation of BH123 proteins in the outer membrane of mitochondria e) none of the above

How does the anti-apoptotic protein, Bcl2, prevent apoptosis? a) by preventing the aggregation of "BH3 only" proteins b) by preventing the aggregation of "BH123" proteins c) by promoting the aggregation of "BH123" proteins d) by phosphorylating the BAD protein e) by returning cytochrome C to the mitochondrion

How is the progress of proteins processed through the Golgi complex monitored? a) by a pattern of phosphorylation b) by modifications of the N-oligosaccharide c) by a program of N-terminal proteolysis d) by the fold of the protein e) by the binding of chaperone proteins

In some cells, the catalytic subunit of protein kinase A (PKA) can enter the nucleus and alter gene expression by phosphorylating which of the following proteins? a) transcription factor A b) cyclic AMP response element binding (CREB) protein c) CREB binding protein (CBP) d) calmodulin e) none of the above

In the MAP kinase pathway, the small GTPase, Ras, is activated by recruitment of which of the following proteins? a) STATs b) Ras-GEF c) Ras-GAP d) PKC e) Rasactin

Is the following statement TRUE of FALSE? "No molecule can traverse the nuclear pore complex without the assistance of a nuclear transport receptor". a) The statement is TRUE b) The statement is FALSE

Is the following statement True or False? Protein kinases always activate their substrate phosphoproteins. a) The statement is True b) The statement is False

Most clathrin-coated vesicles are destined for which of the following cell compartments? a) endoplasmic reticulum b) endosomes c) cis Golgi network d) nucleus e) mitochondria

Prolactin and cytokines signal through which of the following? a) receptor tyrosine kinases b) JAK kinases c) PKA d) Akt kinase e) G-protein coupled receptors

Signal mediated up-regulation of cell surface receptors involves the transfer of sequestered receptors from which of the following compartments? a) late endosomes b) recycling endosomes c) the trans-Golgi network d) the endoplasmic reticulum e) secretory vesicles

Vinculin, together with Talin dimers, couple integrin dimers to the actin cytoskeleton in which of the following cell-cell matrix junctions ? a) hemidesmosomes d) adherens junctions b) focal adhesions e) gap junctions c) tight junctions

What are Caspases? a) proteases that cleave substrates at specific glutamate residues b) proteases that cleave substrates at specific aspartate residues c) protein kinases d) phosphatases that dephosphorylate phosphotyrosine residues e) phosphatases that dephosphorylate phosphothreonine residues

What is the energy source that drives chromosomal segregation during anaphase B? a) the electrochemical gradient across the plasma membrane b) ATP hydrolysis c) GTP hydrolysis d) catastrophic shortening of kinetochore microtubules e) the energy source is not known

What is the term for a receptor that indirectly activates an ion channel on the plasma membrane. a) ionotropic b) metabotropic c) pleotropic d) isotropic e) bizarre

Which of the following binds calcium ions and promotes skeletal muscle contraction? a) tropomodulin b) troponin complex c) tropomyosin d) calmodulin e) contractin

Which of the following cell-cell junctions is responsible for preventing the diffusion of solutes between apical and basolateral extracellular compartments in epithelial tissues? a) desmosomes b) tight junctions c) adherens junctions d) gap junctions e) none of the above

Which of the following events "cocks" the neck linker on myosin II motor proteins? a) ATP binding to the motor head b) ATP hydrolysis c) binding of the motor head to an actin filament d) dissociation of inorganic phosphate from the motor head e) dissociation of the ADP from the motor head

Which of the following is NOT a microtubule organizing center (MOC)? a) centrosome b) centriole c) spindle pole d) basal body e) all of the above are MOCs

Which of the following is phosphorylated by S-Cdk to initiate DNA synthesis a) DNA polymerase b) Cdc6 c) MPF d) ORC e) Helicase

Which of the following kinases is responsible for preventing the assembly of Ndc80 complexes on kinetochore microtubules? a) M-Cdk complex b) aurora-B kinase c) cyclin activating kinase (CAK) d) polo kinase e) MAP kinase

Which of the following kinesin proteins is capable of binding directly to chromatin? a) kinesin 1 b) kinesin 4,10 c) kinesin 5 d) kinesin 13 e) none of the above

Which of the following peptide sequences is composed entirely of non-polar amino acids? a) FACE d) FRAP b) VIAL e) GRIM c) PICK

Which of the following phosphorylates and inactivates the Wee1 kinase at the onset of M-phase? a) p53 b) M-Cdk complex c) S-Cdk complex d) APC e) cdc25

Which of the following refers to the proteins that are cleaved by separase to release sister chromatids at anaphase? a) separins d) anaphase promoting complex (APC) b) cohesins e) cyclin B c) condensins

Which of the following statements is FALSE regarding microtubules? a) microtubules are composed of 13 "protofilaments" b) microtubules grow fastest from the minus (-) end c) microtubules display the property of dynamic instability d) microtubules undergo "catastrophe", during which they fray at the plus (+) end e) all of the above are TRUE regarding microtubules

) What is the ultimate fate of apoptotic cells? a) they aggregate in tissue to form scars b) they are processed to simple compounds by their own enzymes c) they remain quiescent until activation of G1-S Cdk d) they are consumed by macrophages e) they emerge in a parallel universe as components of anti-creatures

Which of the following statements is FALSE regarding the immunoglobulin molecule? a) it is a heterotetramer composed of two light chains and two heavy chains b) there are four antigen binding domains c) the antigen binding domain(s) include elements of both the light and heavy chains d) the light and heavy chains are stabilized by disulfide bonds e) all of the above are TRUE regarding the immunoglobulin domain

Which small GTPase might be activated during remodeling of the actin cytoskeleton? a) Rab d) Ram b) Rac e) dynamin c) Ran

19) You have isolated a temperature sensitive yeast mutant. When maintained at the restrictive temperature, all of the yeast cells are arrested at the Metaphase-Anaphase (M-A) checkpoint due to a loss-of-function mutation of a single gene. Which of the following proteins / protein complexes is most likely responsible for the observed phenotype (i.e., arrest at M-A checkpoint)? a) P53 b) APC c) ARP d) Cyclin D e) Cyclin E

b) APC page 7 cell cycle 2

3) Which of the following events "cocks" the neck linker on myosin II motor proteins? a) ATP binding to the motor head b) ATP hydrolysis c) binding of the motor head to an actin filament d) dissociation of inorganic phosphate from the motor head e) dissociation of the ADP from the motor head

b) ATP hydrolysis

. During receptor mediated endocytosis, which of the following events releases clathrin-coated vesicles from the plasma membrane? a) phosphorylation of clathrin b) dephosphorylation clathrin c) GTP hydrolysis by the RAB GTPase d) GTP hydrolysis by the dynamin complex e) dissociation of the clathrin coat

. Which of the following events terminates signaling through the alpha subunit of a trimeric G-protein complex? a) dissociation of the ligand-receptor complex b) dissociation of the G-protein from the receptor c) GTP exchange d) GTP hydrolysis e) binding of the G-alpha subunit to the beta-gamma complex

. Which of the following proteins directs vesicles to the proper target membrane? a) clathrin b) dynamin c) SNARE proteins d) Rab proteins e) tethering proteins

1) Which of the following compounds binds to actin filaments and is frequently used to as an affinity reagent for fluorescent labeling of the actin cytoskeleton? a) colchicine b) cytochalasin c) taxol d) phalloidin e) vincristine

14) What is the function of the centriole? a) it is required for the production of microtubules b) it is required for the production of the spindle complex c) it is required chromosomal segregation d) it is required for production of cilia e) it has no known function

18) During kinesin movement along a microtubule, which event causes the neck linker to "zipper onto the head domain" (i.e., the "Power Stroke") a) hydrolysis of GTP b) dissociation of Pi c) hydrolysis of ATP d) exchange of ADP for ATP e) exchange of GDP for GTP

2) Which of the following intermediate filaments is found in all animal cells? a) keratins b) vimentin c) neurofilaments d) nuclear lamins e) all of the above are found in all animal cells

21) What is the role of tropomyosin in striated muscle contraction? a) it is the minus (-) end capping protein in striated muscle b) it transmits action potentials to myofibrils c) it opens calcium channels on the sarcoplasmic reticulum d) it blocks myosin binding sites on actin filaments e) it binds calcium and exposes myosin binding sites on actin filaments

24) Which of the following serves as the plus (+) end capping protein of actin filaments in sarcomeres? a) tropomyosin b) troponin c) tropomodulin d) CapZ e) none of the above

26) What is the role of tropomyosin in striated muscle contraction? a) it activates myosin light chain kinase b) it transmits action potentials to myofibrils c) it opens calcium channels on the sarcoplasmic reticulum d) it blocks myosin binding sites on actin filaments e) it binds calcium and moves tropomyosin off myosin binding sites

27) You have isolated a temperature sensitive yeast mutant. When maintained at the restrictive temperature, all of the yeast cells are arrested at the "start" checkpoint (G1-S transition) due to a loss-of-function mutation of a single gene. Below are listed five proteins. Which one is most likely to be the protein responsible for the observed phenotype (i.e., arrest at G1-S transition)? a) P53 b) RB c) P21 d) Cyclin A e) Cyclin B

28) During G1 phase, which of the following prevents entry into S-phase when DNA damage is present? a) mTOR b) cdh1 c) cdc20 d) p53 e) myc

28) MPF refers to the substance(s) present in the cytosol of unfertilized Xenopus oocytes that is capable of driving multiple cycles of M phase and S phase in vitro. What is MPF? a) Momma's Powerful Force b) Metaphysical Procreation Factor c) Mitotic Progress Facilitator d) Maturation Promoting Factor e) None of the above

33) Which of the following refers to the phosphatase that activates M-Cdk to initiate M-phase? a) phosphatase B b) M phosphatase c) cdc15 d) cdc25 e) none of the above

34) What is the role of the cyclin component of Cdk complexes (e.g., M-Cdk)? a) phosphorylates and activates the kinase b) dephosphorylates and activates the kinase c) prevents phosphorylation of the inhibitory site of the kinase d) determines the substrate specificity of the kinase e) none of the above

34) Which of the following refers to the SMC protein complex that gathers and organizes newly replicated DNA into chromosomes ? a) gatherin b) compactin c) cohesin d) condensin e) compressin

35) Which of the following events occurs during prometaphase? a) breakdown of the nuclear envelope b) maturation of the spindle complex c) fixation of kinetochore microtubules d) all of the above occur during prometaphase e) none of the above occur during prometaphase

39) At the anaphase checkpoint, which of the following events must occur for mitosis to proceed? a) phosphorylation of securin b) ubiquination of APC c) phosphorylation of cyclin B d) ubiquination of cyclin B e) none of the above

41) How does P53 activation prevent entry into S-Phase? a) by phosphorylating S-cdk b) by promoting the expression of cyclin E c) by inhibiting APC d) by promoting the synthesis of Cdk inhibitors e) P53 activation does not prevent entry into S-phase

43) During G1 phase, which of the following prevents entry into S-phase when DNA damage is present? a) mTOR b) Hct1 c) cdc20 d) P53 e) Myc

46) How does cytochrome C initiate apoptosis? a) it promotes the aggregation of BH123 proteins in the outer membrane b) it aggregates to form channels in the outer mitochondrial membrane c) it directly activates executioner procaspases d) it promotes the aggregation of initiator procaspases e) none of the above

21) Which of the following statements regarding HSP70-type molecular chaperones is TRUE? a) ATP hydrolysis results in the binding of chaperone proteins to polar amino acids on the target protein. b) ATP hydrolysis results in the binding of chaperone proteins to non-polar amino acids on the target protein. c) GTP hydrolysis results in the binding of chaperone proteins to polar amino acids on the target protein. d) GTP hydrolysis results in the dissociation of chaperone proteins from hydrophobic amino acids on the target protein. e) None of the above statements are true.

b) ATP hydrolysis results in the binding of chaperone proteins to non-polar amino acids on the target protein.

20) Activation of the phosphatidylinositol 3 (PI-3) kinase pathway results in activation of which of the following enzymes? a) adenylyl cyclase b) Akt kinase c) MAP kinase d) cyclin dependent kinase 1 e) none of the above

b) Akt kinase

24) Which of the following is phosphorylated by S-Cdk to initiate DNA synthesis during S-phase? a) DNA polymerase b) Cdc6 c) MPF d) ORC e) Helicase

b) Cdc6 page 13 cell cycle 1

11) Which of the following proteins directs transport vesicles to the target membrane? a) Ran GTPase b) Rab GTPase c) Ras GTPase d) Rac GTPase e) dynamin

b) Rab GTPase The Rabbi tells the vesicle to how go about their journey

31) Which small GTPase is often activated during mitogen signaling? a) Rab d) Ran b) Ras e) Alsoran c) Rac

b) Ras

36) Which of the following proteins is required to sustain APC activity during G1? a) cyclin D b) Rb c) cdc25 d) p53 e) cdh1

b) Rb page 12 cell cycle 2

46) What is the ultimate fate of apoptotic cells? a) they aggregate in tissue to form scars b) they are processed to simple compounds by their own enzymes c) they remain quiescent until activation of G1-S Cdk d) they are consumed by macrophages e) they emerge in a parallel universe as components of anti-creatures

31) All cell-matrix junctions include which of the following cell adhesion molecules? a) desmocollin b) integrin dimers c) claudin d) classical cadherins e) non-classical cadherins

b) integrin dimers page 9 and 11 extracellular matrix

43) Which of the following CAMs are components of focal adhesions and hemidesmosomes? a) selectins d) N-CAMs b) integrins e) I-CAMs c) cadherins

b) integrins focal adhesions and hemidesmosomes are cell-to matrix... this is controled by integrin

41) Which of the following cell adhesion molecules (CAMs) is NOT a component of cell-cell junctions? a) selectins d) N-CAMs e) I-CAMs c) cadherins

b) integrins (they are cell-matrix)

34) Nuclear lamins are members of which protein class? a) actin binding proteins b) intermediate filament proteins c) neurofilament proteins d) microtubule binding proteins e) nuclear pore complex proteins

b) intermediate filament proteins

34) How does cytochrome C initiate apoptosis? a) it directly activates executioner procaspases b) it promotes the aggregation of initiator procaspases c) it oxidizes cytoplasmic proteins d) it disrupts oxidative phosphorylation e) cytochrome C is a mitochondrial protein, and has nothing to do with apoptosis.

b) it promotes the aggregation of initiator procaspases

33) How does cytochrome C initiate apoptosis? a) it directly activates executioner procaspases b) it promotes the aggregation of initiator procaspases c) it aggregates to form channels in the outer mitochondrial membrane d) it promotes the aggregation of BH123 proteins in the outer membrane of mitochondria e) none of the above

b) it promotes the aggregation of initiator procaspases page 5 apoptosis (initiator=cytochrome c effector=procaspases)

27) Phospholipase C activation leads to the production of (at least) two signaling molecules; IP3 and diacylglycerol. What is the function of diacylglycerol? a) it activates receptors on the smooth endoplasmic reticulum, resulting in the release of calcium into the cytosol b) it recruits protein kinase C to the plasma membrane c) it activates adenylyl cyclase d) it activates guanylyl cyclase e) none of the above

b) it recruits protein kinase C to the plasma membrane B is what IP3 does

49) Which of the following kinesin proteins is capable of binding directly to chromatin? a) kinesin 1 b) kinesin 4,10 c) kinesin 5 d) kinesin 13 e) none of the above

b) kinesin 4,10 page 3 cell cycle 2

28) Raf, MEK and ERK are members of which of the following kinase families? a) calcium-calmodulin (CAM) kinases b) mitogen activated kinases c) janus kinases

b) mitogen activated kinases "MEK" "Raf" "ERK"

27) Constriction of the contractile ring during cytokinesis is driven by ... a) myosin I b) myosin II c) dynein d) kinesin 5 e) none of the above

b) myosin II the cell splits into 2 using myosin II

25) Signaling that is restricted to non-adjacent cells within the same tissue is called ... a) endocrine signaling b) paracrine signaling c) transcytosis d) contact dependent signaling e) early postmodern signaling

b) paracrine signaling

59) Which of the following is NOT required for the activation of M-Cdk? a) binding of cyclin B b) phosphorylation of cyclin B c) phosphorylation of M-Cdk at the stimulatory site d) dephosphorylation of M-Cdk at the inhibitory site e) all of the above are required for full activation of M-Cdk

b) phosphorylation of cyclin B B-asically don't P in a CYCLE

1) Which of the following is NOT a structure comprised mostly of actin filaments? a) stress fiber b) primary cilium c) lamellipodium d) contractile ring e) micorvilli

b) primary cilium page 2 cytoskeleton 3

57) Breakdown of the nuclear envelop occurs during which phase of mitosis? a) prophase b) prometaphase c) metaphase d) anaphase e) telophase

b) prometaphase in prophase the replicated chromosomes JUST condense (and mitotic spindle assembles)... in metaphase the chromosomes line up in the middle thus you need prometaphase to break the nucleated envelope so that the condensed chromosomes (prophase I) can move to the middle (metaphase I)

42) What are Caspases? a) proteases that cleave substrates at specific glutamate residues b) proteases that cleave substrates at specific aspartate residues c) protein kinases d) phosphatases that dephosphorylate phosphotyrosine residues e) phosphatases that dephosphorylate phosphothreonine residues

b) proteases that cleave substrates at specific aspartate residues page 3 Apoptosis

3) Which of the following best describes the apical-to-basolateral order of occurrence of cell-cell junctions in an epithelial sheet? a) tight junctions - desmosomes - adherens junctions - gap junctions b) tight junctions - adherens junctions - desmosomes - gap junctions c) tight junctions - adherens junctions - gap junctions - desmosomes d) adherens junctions - tight junctions - gap junctions - desmosomes e) adherens junctions - tight junctions - desmosomes - gap junctions

b) tight junctions - adherens junctions - desmosomes - gap junctions

14) Which of the following cell-cell junctions is responsible for preventing the diffusion of solutes between apical and basolateral extracellular compartments in epithelial tissues? a) desmosomes b) tight junctions c) adherens junctions d) gap junctions e) none of the above

b) tight junctions page 11 cell junctions

47) When does "catastrophe" occur? a) when ATP levels are exhausted b) when the microtubule looses it's "GTP cap" c) when the GTP-bound form of tubulin dimer falls below the critical concentration d) when microtubules contact the plasma membrane e) when microtubules reach a certain age

b) when the microtubule looses it's "GTP cap"

what is the largest molecule that can pass through the nuclear pore complex without a nuclear transport receptor a. 2 kD b. 5 kD c. 10 kD d. 25 kD e. all of the above

b. 5 kD

How many doublet microtubules are in an axoneme (e.g., flagellum) a. 8 b. 9 c. 11 d. 13

b. 9

how many doublet microtubules are in an anxoneme (e.g flagellum) a. 8 b. 9 c. 11 d. 13 e. 15

b. 9

Activation of the phosphatidylinositol 3 (PI-3) kinase pathway results in activation of which of the following proteins? a. protein kinase A b. Akt kinase c. MAP kinase d. cyclin dependent kinase 1 e. none of the above

b. Akt kinase

Some "survival signals" prevent apoptosis through phosphorylation of the BAD protein, resulting in release of the anti-apoptotic protein, Bcl2. Which of the following kinases phosphorylates the BAD protein? a. protein kinase A b. Akt kinase c. MAP kinase d. cyclin dependent kinase 1 e. none of the above

b. Akt kinase

A temperature sensitive cdc mutant yeast strain possesses a loss-of-function mutation of cyclin B. At the restrictive temperature, cell cycle arrest will occur at which of the following control points? a. G1 - S checkpoint b. G2 - M checkpoint c. metaphase - anaphase checkpoint d. M - G1 checkpoint e. cell division will proceed at the restrictive temperature

b. G2 - M checkpoint

44. What is the role of the modified base, 7-methylguanosine? a. It is formed during chromatin remodeling b. It forms the 5' cap of messenger RNA c. It marks the 5' spice site of an exon d. It is produced spontaneously as a point mutation e. none of the above

b. It forms the 5' cap of messenger RNA

25. What is the function of the tail domain of RNA polymerase II? a. It contains the catalytic site b. Post-transcriptional modifiers of mRNA are recruited there c. It binds to the TATA box d. It launches the polymerase e. It binds sigma factors

b. Post-transcriptional modifiers of mRNA are recruited there for RNA pol the post transcription factors tail it

8. The TATA box binding protein is a subunit of which of the following general transcription factors? a. TFIIB b. TFIID c. TFIIF d. TFIIG e. TFIIH

b. TFIID sub-u-**** (just like this question)

which of the following proteins reeleases calcium from the sacroplasmic reticulum in response to muscle depolarization a. voltage gated calcium channel b. a calcium gated calcium channel c. an M type calcium atpase d. a spdium calcium antiporter e. an ip3 receptor

b. a calcium gated calcium channel

the organization of the actin cytockeleeton is primarily controlled by which of the following a. myosin motor proteins b. actin binding proteins c. protein kinases d. concetration of g actin e. concentration of atp

b. actin binding protein s

the organization of the actin cytoskeletion is primarily controlled by which of the follwing a. protien kinases b. actin binding proteins c. small gtpases d. transcritpion factos e. phase of the moon

b. actin binding proteins

what provides the force that drives protrusion of the leading edge of a motile cell a. microtubule polyermization b. actin polyermization c. myosin I motors d. myosin II motors e. dyenin motors

b. actin polyermization

the gaseous messenger, nitric oxide, is produced by nitric oxide synthase from which of the following precursors a. asparagine b. arginine c. alanine d. nitrate e. nitrous oxide

b. arginine

what is the energy source that drives chromosomal segregation during anaphase b a. the electrochemical gradient across the plasma membrane b. atp hydrolysis c. gtp hydrolysis d. catastrophic shortening of kinetochrore microtubules e. the energy source is not known

b. atp hydrolysis

During RTK signaling, ligand binding results in receptor dimerization. Which event happens next? a. activation of the Ras GTPase b. autophosphorylation of both receptors c. recruitment of other signaling proteins d. assembly of the signaling complex e. synthesis of cAMP

b. autophosphorylation of both receptors

which of the following events occurs during signaling through the wnt pathway. a. cyclic gmp is hydrolyzes to 5' gmp b. beta catenin accumulates and enters the nucleus c. the ras onogene activates the mapk cascade

b. beta catenin accumulates and enters the nucleeus

what is role of the troponin complex in striated muscle contraction a. opens calcium channels on the sarcoplasmic reticulum b. binds calcium and releases tropomyosin c. activated myosin light chain kinase d. blocks myosin binding sites on actin filaments e. transmits action potentials to myofibrils

b. binds calcium and releases tropomyosin

which of the following is false regarding tubulin dimers a. they are composed of alpha and beta subunits b. both the alpha and beta subunits bind atp c. only the beta subunit can hydrolyze its bound nucleotide d. the beta subunit is always exposed at the plus end of the microtubule e. all of the above

b. both the alpha and beta bind atp

In quiescent cells, as much as 95% of actin protein is ... a. bound to the cell cortex b. bound to profilin and thymosin c. bound to actin accessory proteins d. free to polymerize into actin filaments e. already incorporated into actin filaments

b. bound to profilin and thymosin

What event terminates muscle contraction? a. ATP levels are exhausted b. calcium ions are transported back into the sarcoplasmic reticulum c. myosin head groups are phosphorylated by myosin light chain kinase d. acetylcholine is degraded by acetylcholine esterase e. sodium channels inactivate

b. calcium ions are transported back into the sarcoplasmic reticulum

which of the following events usually terminates muscle contraction a. atp levels are exhausted b. calcium ions are transported back into the sacroplasmic reticulum c. myosin head groups are phosphorylated by myosin light cheain kinase d. acetylcholine is degraded by acetylcholine esterase e. sodium channels inactivate

b. calcium ions are transported back into the sarcoplasmic reticulum

which of the following is phosphorylated by s cdk to initiate dna synthesis a. dna polyermase b. cdc6 c. mpf d. orc e. helicase

b. cdc6

which of the following is not a microtubule organizing center a. centrosome b. centriole c. spindle pole d. basal body e. all of the above

b. centriole

Which of the following actin accessory proteins binds to and destabilizes actin filaments? a. profilin b. cofilin c. fimbrin d. formin e. filamin

b. cofilin

pka often activates gene expression by phosphorylating which of the following proteins a. creb protein b. creb binding protein c. stat d. map kinase e. none of the above

b. creb binding protein

a loss of function mutation of p 53 gene would result in a. a increased p 21 expression leading to arrest of the cellc ycle at g1 b. decreased p 21 expression leading to unregulated entry into s phase c. decreased probability of replication of damaged dna d. increased biosynthesis of genes controlling s phase events e. decreased biosynthesis of genes contolling g1 pahse events

b. decreased p 21 expression leasding to unregulated entry into s phase

during g protein coupled receptor signaling through adenyly cyclase which of the following events terminates the signal process a. reassembly of the trimeric g protein complex b. degredation of the camp by phosphodiestaerase c. dissociation of the ligand from the gpcr d. gtp hydrolysis of the G alpha subunit

b. degradation of the cmap by pshosphodiesterase

cytoplasmic dyneins are.... a. dimeric plus end directed microtubule motor proteins b. dimeric minus end directed microtubule motor proteins c. trimeric plus end directed microtubule motor proteins d. trimeric minus end directed microtubule motor proteins e. components of the nuclear envelope

b. dimeric minus end directeed microtubule motor proteins

which of the following events occurs during prometaphase a. dna replication b. disintegration of nuclear envelope c. ubiquination of cyclin b d. inactivation of apc e. formation of the contractile ring

b. disintegration of the nuclear envelope

what event in the snare cycle requires the hydrolysis of atp a. binding of v-snare to t-snares b. dissociation of snare complexes c. binding of rab gtpases to the snare complex d. dissociation of rab gtpases from the snare complex e. binding of rab gtpases to the tethering protein complex

b. dissociation of snare complexes

for myosin motors which of the the following events occurs immediataly before the power stroke a. exchange of adp for atp b. dissoication of pi c. hydrolysis of gtp d. hydrolysis of atp e. dissociation of adp

b. dissoication of pi

Which of the following motor proteins always travels toward the minus (-) end of microtubules? a. kinesins b. dyneins c. myosin I d. myosin II e. all of the above are plus end directed motor proteins

b. dyneins

which of the following motor proteins always travels toward the inus end of the microtubules a. kinesins b. dyenins c. mysoin I d. mysoin II e. all of the above

b. dyneins

the unfolded protein response pathway results in biosynthesis of which of the following proteins a. cytosolic chaperone proteins b. er chaperone proteins c. ribosomal proteins d. nuclear import receptors e. none of the above

b. er chaperone proteins

during signaling through a g protein coupled receptor which event activates the alpha subunit of the trimeric g protein a. dissociation from the beta gamma complex b. exchange of gp for gtp c. atp hydrolysis d. gtp hydrolysis e. binding to the beta gamma complex

b. exchange of gdp for gtp

What are T-tubules? a. components of the sarcoplasmic reticulum b. extensions of the muscle cell plasma membrane c. triplet microtubules found in the centriole and basal bodies d. modified endoplasmic reticulum e. none of the above

b. extensions of the muscle cell plasma membrane

misfolded proteins that appear in the trans golgi network are packaged into vesciles and delivered to which of the following campartments a. endosome b. the extracellualr compartment c. the cytoplasm

b. extracellualr compartment

during receptor mediated endocytosis which event recruits adaptins to the plasma membrane a. phosphorylation of membrane proteins b. formation of receptor ligand complexes c. changes in phospholipid asymmetry d. gtp hydrolysis by the dynamin complex e.binding of clathrin

b. formation of receptor ligand complexes

which of the following kinase cyclin pairs is correctly matched a. s cdk and cyclin b b. g1 - s cdk and cyclin e c. m cdk and cyclin c d. g1 cdk and cyclin a e. all are correctly matched

b. g1 s cdk and cyclin e

which of the following intiates microtubule polymerization a. formins b. gamma tublin tring complexes c. centrioles d. mocrotubule fragments e. none of the above

b. gamma tublin ring complexes

which of the following initiates microtubule polymerization a. formin dimers b. gamma tubulin ring complexes c. centrioles d. actin binding proteins e. none of the aboce

b. gamma tubulin ring complexes

which of the following statements is false regarding microtubule a. composed of 13' protofilaments b. grow fastest from the minus end c. display the property of dynamic instability d. undergo 'catastrophe' during which they fray at the plus end e. all of the above are trye

b. grow fastest from the minus end

during signaling through a g protein coupled receptor, which event inactivates the alpha subunit of the trimeric g protein a. atp hydrolysis b. gt hydrolysis c. binding to the beta gamma complex d. dissociation from the beta gamma complex e. exchange of gtdp for gdp

b. gtp hydrolysis

How do mitogens stimulate mitotic activity? a. inhibition of p53 b. increased expression of myc c. inhibition of Hct1-APC d. degradation of p21 e. none of the above

b. increased expression of myc

which of the following messenger molecules does NOT signal through a soluble (also called 'nuclear') receptor a. testerone b. insulin c. thyroxine d. estrogen e. all of the above

b. insulin

Nuclear lamins are members of which protein class? a. actin binding proteins b. intermediate filaments c. neurofilaments d. microtubule binding proteins e. nuclear pore complex proteins

b. intermediate filaments

how does tropmysoin prevent muscle contraction in the absence of calcium signals a. it hydrolyzes atp b. it blocks mysoin binding sites on the actin filament c. it blocks actin binding sites on the myosin II head domains d. it blocks actin binding on the myosin II neck domains e. none of above

b. it blocks mysoin sites on the actin filaments

3. How does the DNA mismatch repair system recognize and repair only the newly synthesized strand? a. it is warmer than the template strand b. it contains "nicks" left over from lagging strand synthesis c. it detects irregularities in the shape of the double helix d. the hydrogen bonds are stronger on the template side e. it chooses a strand at random

b. it contains "nicks" left over from lagging strand synthesis

during apotosis how does cytochrome c get out of the mitochondrion a. it leaves through channels formed by bj3 only proteins b. it leaves through channels formed by bh123 proteind c. it aggregates to form clusters that are membrane permeable d. it binds to bh123 proteins and enters the cytosol e. it binds to bcI2

b. it leaves threough channels formed by bh123 proteins

what is the function of the gtp cap on microtubule a. it is binding site for kinesin motors b. it prevents catastrophic shortening of the microtubules c. it prevents the hydrolysis of gtp by the alpha subunit d. it prevents the hydrolysis of gtp by the beta subunit e. it is no consequence

b. it prevents catastrophic shortening of the microtubule

which of the following is an intermediate filament protein found in all animal cells a. vimentin b. lamin a c. keeratin d. collogen e. none of the above

b. lamin a

29. What is the energy source for active transport of protons (H+) by bacteriorhodopsin? a. heat b. light c. ATP hydrolysis d. GTP hydrolysis e. transmembrane sodium gradient

b. light

which of the following phosphorylates and inactivates the wee 1 kinase at the onset of m phase a. a p53 b. m cdk complex c. scdk complex d. apc e. cdc25

b. mcdk complex

light induced activation of the g protein coupled receptor, rhoposin, results in which of the following changes in rod photoreceptor cells a. membrane depolarizaion b. membrane hyperpolarization c. accumulation of cyclic amp d. accumulation of cyclic gmp e. increased neurotransmitter release

b. membrane hyperpolarization

12. Which amino acid is carried by the initiator tRNA? a. proline b. methionine c. lysine d. serine e. none of the above

b. methionine START-MET

Raf, MEK and ERK are members of which of the following kinase families? a. calcium-calmodulin (CAM) kinases b. mitogen activated kinases c. janus kinases d. cyclin-dependent kinases e. none of the above

b. mitogen activated kinases

during the misfolded protein response a transcription factor is activated that drives the expression of certain proteins. which of the following proteins is most highly expressed during the misfolded protein response. a. nuclear transport receptors b. molecular chaperones c. dna polyermase d. snare proteins e. ubiquitin

b. molecular chaperones

which of the motor proteins is responsible for the constriction of the contractile ring during cytokinesis a. myosin I b. myosin II c. dynein d. kinesin 5

b. myosin II

50) How does cytochrome C initiate apoptosis? a) it promotes the aggregation of BH123 proteins in the outer membrane b) it aggregates to form channels in the outer mitochondrial membrane c) it directly activates executioner procaspases d) it promotes the recruitment of initiator procaspases e) none of the above

24. Which of the following events is responsible for the repolarizing phase of the action potential? a. opening of voltage gated sodium channels b. opening of voltage gated potassium channels c. closing of voltage gated potassium channels d. opening of voltage gated chloride channels e. closing of voltage gated chloride channels

b. opening of voltage gated potassium channels

nitric oxide is an eexample of which of the following a. endocrine messenger b. paracrine messenger c. neurotransmitter d. cell contact ligand

b. paracrine messenger

during embryonic development, the fate of uncommitteed cells is often determine by their location along an extracellular gradient of a diffusable 'morphogen'. this is an example of which of the following signaling strategies a. endocrine signaling b. paracrine signaling c. contact dependent signaling d. synaptic signaling

b. paracrine signaling

singaling that is restricted to a few nearby cells within the same is called what a. endocrine signaling b. paracrine signaling c. transcytosis d. contact dependent signaling e. early postoderm signaling

b. paracrine signaling

50) Which of the following cell-cell junctions is formed by cell adhesion molecules that are associated with actin filaments? a) desmosomes d) adherens junctions b) focal adhesions e) gap junctions c) tight junctions

51) Which of the following cell-cell junctions is formed by cell adhesion molecules that are associated with actin filaments? a) desmosomes d) adherens junctions b) focal adhesions e) gap junctions c) tight junctions

Which of the following is NOT required for the full activation of M-Cdk? a. binding of cyclin B b. phosphorylation of cyclin B c. phosphorylation of M-Cdk at the stimulatory site d. dephosphorylation of M-Cdk at the inhibitory site e. all of the above are required for full activation of M-Cdk

b. phosphorylation of cyclin B

7. What are Shine-Delgarno sequences? a. eucaryotic ribosomal binding sites b. procaryotic ribosomal binding sites c. spliceosome binding sites d. RNA polymerase binding sites e. enhancer binding sites

b. procaryotic ribosomal binding sites bacteria need some shine to start working (cause they are dirty and cause illnesses) • Bacteria use a Shine-Delgarno sequence (~6 bps long= AGGAGG) upstream of the AUG to cue the start of translation, while eukaryotes use a Kozak sequences (GCCGCCAUGG).

Which event immediately precedes/triggers chromosomal segregation? a. degradation of cdk1 b. proteolytic cleavage of cohesins by separase c. ubiquination of cyclin B by anaphase promoting complex (APC) d. degradation of cyclin B e. activation of kinesin motors

b. proteolytic cleavage of cohesins by separase

which smal gtpase might be activated during remodeling of the actin cytoskeleton a. rab b. rac c. ran d. ram e. dynamin

b. rac

directional transport through nuclear pore complexes is primarily due to which of the following a. restriction of ran gap to the nuclear compartment b. restriction of ran gef to the nuclear compartment c. restriction of ran gef to the cytosolic compartment d. movement f ran gef from the nucleus to the cytosolic compartment e. a gradient of gtp across the nuclear envelope

b. restriction of ran gef to the nuclear compartment

9) Phospholipase Cβ activation leads to the production of (at least) two signaling molecules inositol 1,4,5-trisphosphate (IP3) and diacylglycerol. What is the function of IP3? a) it activates adenylyl cyclase b) it recruits protein kinase C to the plasma membrane c) it phosphorylates PIP2 d) it promotes the release of Ca2+ from the ER e) none of the above

At the intestinal epithelium of the neonatal gut, maternal antibodies present in breast milk are acquired by receptor-mediated endocytosis across the apical membrane. How are they delivered to the interstitial compartment? a) they are passively transported across the basolateral membrane b) they are actively transported across the basolateral membrane c) they are packaged into transport vesicles by early endosomes d) they are packaged into secretory vesicles by recycling endosomes e) they are processed at the level of the gut epithelium and do not enter the interstitial compartment.

During vesicle formation at the plasma membrane, clathrin triskelions bind to which of the following proteins? a) cargo proteins b) cargo receptors c) adaptin receptors d) adaptins e) none of the above

How does cytochrome C initiate apoptosis? a) it promotes the aggregation of BH123 proteins in the outer membrane b) it aggregates to form channels in the outer mitochondrial membrane c) it directly activates executioner procaspases d) it promotes the recruitment of initiator procaspases e) none of the above

How is vesicular fusion powered? a) GTP hydrolysis drives the formation of SNARE complexes b) ATP hydrolysis drives the formation of SNARE complexes c) GTP hydrolysis drives the dissociation of SNARE complexes d) ATP hydrolysis drives the dissociation of SNARE complexes e) None of the above

which of the following proteins does not participate in calcium homeostasis in the cell a. sodium calcium antiporter on the plasma membrane b. sodijm calcium anitporter on the endoplasmic reticulum c. calcium binding proteins in the cytoplasm d. calcium ATPase on the plasma membrane e. calcium ATPase on the smooth endoplasmic reticulum

b. sodium calcium antiporter on the endoplasmic reticulum

Which of the following toxins binds to and stabilizes microtubules? a. cytochalasin B b. taxol c. colchicine d. phalloidin e. vinblastin

b. taxol

which of the following toxins binds to and stablizes microtubules a. coclchine b. taxol c. cytochalisin B d. phallodin e, none of the above

b. taxol

which of the following toxins binds to and stablizies microtubulues a. cytochalsin B b. taxol c. colchicine d. phalloidin e. vinblastin

b. taxol

during kinesin movement along a microtubule what happens immediately after nucleotide exchange a. the motore head releases the microtubule b. the neck linker zippers onto the the leading head c. the trailing head dissociates d. the leading head binds tightly e.d the leading head is thrust forward

b. the neck linker zippers onto the leading head

What is the ultimate fate of apoptotic cells? a. they remain quiescent until activation of G1-S Cdk b. they are consumed by macrophages c. they aggregate in tissue to form scars d. they are processed to simple compounds by their own enzymes e. they emerge in a parallel universe as components of anti-creatures

b. they are consumed by macrophages

Which of the following is false regarding dynein motors? a. most are cytoplasmic proteins b. they move toward the plus (+) end of microtubules c. they are ATPases d. the cytoplasmic forms are homodimers e. all of the above are true regarding dynein motors

b. they move toward the plus (+) end of microtubules c. they are ATPases

which of the following is flase regarding dynein motors a. most are cytoplasmic b. they move toward the plus end of microtubules c. they are atpases d. the cytoplasmic forms aree homodimers e. all of the above are true

b. they move toward the plus end of microtubules

In the sarcomere, which of the following proteins serves as the minus (-) end cap of actin filaments? a. topomyosin b. topomodulin c. capZ d. nebulin e. titin

b. topomodulin

which of the following binds calcium ions and promotes skeletal muscle contraction a. tropomodulin b. troponin complex c. tropomyosin d. calmodulin e. contractin

b. troponin complex

the low ph lysoomes is generated and maintained by which of the following a. na+/ hco3 symporter b. v-type powered h pump c. na+ / H+ antiporter d. Na+/H+ e. none above

b. v-type atp powered H+ pump

when does 'catastrophe' occur a. when atp levels are exhausted b. when the microtubule looses it gtp cap c. when the gtp-bound form of tubulin dimere falls below the critical concentration d. when microtubules contact the plasma membrane e. when microtubules reach a certain age

b. when the microtubule looses its gtp cap

when does catastrophe occur a. when atp levels are exhausted b. when the microtubule loses its gtp cap c. when the gtp bound form of tubulin dimer falls below the crtitcal concentration d. when the microtubule reach a certain age e. when microtubules contact the plasma membrane

b. when the microtubule loses it gtp cap

In the auditory system, "hair cells" are depolarized during activation of which of the following ion channels? a) ungated cation channels b) ligand-gated cation channels c) ligand-gated anion channels d) mechanically-gated cation channels e) mechanically-gated anion channels

The endosymbiosis hypothesis concerns which of the following organelles ? a) nucleus and mitochondria b) nucleus and chloroplasts c) nucleus and lysosome d) mitochondria and chloroplasts e) mitochondria and lysosomes

The nuclear envelope disintegrates during which phase of mitosis? a) telophase b) anaphase c) metaphase d) prometaphase e) prophase

What is a "Stokes Shift"? a) a component of the gear box in a 1957 Chevy Bellaire b) a dance move developed by Fred Astaire and Ginger Stokes Rogers c) a gravitational anomaly in the Crab Nebula d) the difference between the peak absorbance and peak emission wavelengths of a fluorochrome e) none of the above

What is a role of the cyclin component of Cdk complexes (e.g., M-Cdk)? a) phosphorylates and activates the kinase b) dephosphorylates and activates the kinase d) prevents phosphorylation of the inhibitory site of the kinase d) determines the substrate specificity of the kinase e) none of the above

What is the energy source that drives chromosomal segregation during anaphase B? a) hydrolysis of cohesins b) kinetochore microtubule catastrophe c) GTP hydrolysis d) ATP hydrolysis e) The Force

What is the role of the troponin complex in striated muscle contraction? a) it activates myosin light chain kinase b) it transmits action potentials to myofibrils c) it opens calcium channels on the sarcoplasmic reticulum d) it binds calcium and moves tropomyosin off myosin binding sites e) it blocks myosin binding sites on actin filaments

When a differentiating cell displays the Delta ligand, adjacent cells that express the Notch receptor do which of the following. a) they divide b) they do not divide c) they become neurons d) they do not become neurons e) they deeply regret it

Which of the following cell-matrix junctions is formed by cell adhesion molecules that are associated with actinfilaments? a) tight junctions d) focal adhesions b) adherens junctions e) gap junctions c) desmosomes

Which of the following compounds binds to actin filaments and is frequently used to as an affinity reagent for fluorescent labeling of the actin cytoskeleton? a) colchicine b) cytochalasin c) taxol d) phalloidin e) vincristine

Which of the following events is mediated by a calcium-gated calcium channel? a) action potential generation b) action potential propagation c) neurotransmitter release d) muscle contraction e) extension of the lamellipodium

Which of the following events is responsible for the repolarization phase of the action potential? a) opening of voltage gated sodium channels b) opening of voltage gated potassium channels c) inactivation of voltage gated sodium channels d) two of the above e) all of the above

Which of the following events propels the lamellipodium of a motile cell forward? a) kinesin motor proteins b) myosin motor proteins c) ATP hydrolysis d) actin polymerization e) microtubule polymerization

Which of the following kinesin proteins plays a key role in the Anaphase A process? a) kinesin 1 b) kinesin 4,10 c) kinesin 5 d) kinesin 13 e) none of the above

Which of the following proteins transports monovalent cations against their concentration gradient? a) sodium-calcium antiporter b) sodium-glucose symporter c) passive potassium channels d) sodium-potassium ATPase e) none of the above transports monovalent cations against their concentration gradients

Which of the following refers to the SMC protein complex that gathers and organizes newly replicated DNA into chromosomes ? a) gatherin b) compactin c) cohesin d) condensin e) compressin

Which of the following refers to the SMC protein complex that gathers and organizes newly replicated DNA into chromosomes? a) gatherin b) compressin c) cohesin d) condensin e) chromatin

45) Which of the following proteins is most concentrated at the leading edge of a motile cell? a) myosin I b) myosin II c) formins d) ARPs e) all of the above are concentrated at the leading edge of a motile cell

d) ARPs=Actin Related Proteins actin acts at the leading edge

32) What is the energy source that drives chromosomal segregation during anaphase B? a) hydrolysis of cohesins b) kinetochore microtubule catastrophe c) GTP hydrolysis d) ATP hydrolysis e) The Force

d) ATP hydrolysis page 9 cytoskeleton 2 *know Anaphase a is ATP independent and Anaphase B is ATP dependent

0) Which of the following sarcomere proteins is found at the Z disc? a) tropomyosin b) troponin c) tropomodulin d) CapZ e) none of the above

d) CapZ

51) Which of the following sarcomere proteins serves as a (+) end actin capping protein? a) tropomyosin b) troponin c) tropomodulin d) CapZ e) none of the above

d) CapZ if you have more caps you are postively happy CapZ = (+) end actin capping protein Tropomodulin = (-) end actin capping protein Titin = structural support & recoil (not ABP)

6) The ER misfolded protein response pathway results in biosynthesis of which of the following proteins? a) ribosomal proteins b) nuclear import receptors c) cytosolic chaperone proteins d) ER chaperone proteins e) none of the above

d) ER chaperone proteins

52) The substance in the cytoplasm of M-phase cells that promotes mitosis in cell-free extracts of Xenopus oocytes was originally called ... a) Mammalian Prometaphase Factor b) Maternal Procreation Factor c) Momma's Powerful Force d) Maturation Promoting Factor e) None of the above

d) Maturation Promoting Factor

4) Which of the following events propels the lamellipodium of a motile cell forward? a) kinesin motor proteins b) myosin motor proteins c) ATP hydrolysis d) actin polymerization e) microtubule polymerization

d) actin polymerization page 11 cytoskeleton 3

1) Which of the following cell-cell junctions is formed by cell adhesion molecules that are associated with actin filaments? a) desmosomes d) adherens junctions b) hemidesmosomes e) gap junctions c) tight junctions

d) adherens junctions

31) What is/are the role(s) of the cyclin subunit of cyclin-dependent protein kinases? a) it determines the substrate specificity of the kinase b) it is an allosteric modulator of the kinase c) it is absolutely required for kinase activity d) all of the above e) none of the above

d) all of the above

33) How do survival factors prevent apoptosis? a) decreased synthesis of caspases b) increased degradation of caspases c) direct inhibition of caspases d) biosynthesis of the Bcl-2 protein e) all of the above

d) biosynthesis of the Bcl-2 protein Bak and Bax promote cell death (through cytochrome C and apoptosome and the caspases) Bcl-2 prevent death (through blocking Bax and Bak. Bad blocks the activity of Bcl2 which promotes cell death again)

20) How do living cells satisfy the Second Law of Thermodynamics? a) by releasing heat into the environment b) by absorbing heat from the environment c) by releasing small molecules into the environment d) by releasing macromolecules into the environment e) all of the above

d) by releasing macromolecules into the environment

55) S-Cdk complex initiates DNA replication by phosphorylating which of the following? a) origin of replication complex b) p21 c) M-Cdk d) cdc6 e) none of the above

d) cdc6 so the S-cdk wants to go to S phase... to do this you need to SyntheSize replicated DNA. So if i were a triploid (gen lab exam ew) then you need to have six chromos total... then you need to "use" cdc-Six to even Start the SyntheSiS!!!

19) Which of the following proteins is NOT phosphorylated by M-Cdk? a) APC b) lamins c) cdc25 d) cohesins e) all of the proteins listed above are phosphorylated by M-Cdk

d) cohesins

25) Which of the following refers to the SMC protein complex that gathers and organizes newly replicated DNA into chromosomes? a) gatherin b) compressin c) cohesin d) condensin e) chromatin

d) condensin page 16 cell cycle 1

14) MPF activity is attributed to which of the following proteins? a) cyclin A b) cyclin B c) cyclin C d) cyclin dependent kinase 1 (Cdk1) e) cyclin dependent kinase 2 (Cdk2)

d) cyclin dependent kinase 1 (Cdk1)

27) What is a role of the cyclin component of Cdk complexes (e.g., M-Cdk)? a) phosphorylates and activates the kinase b) dephosphorylates and activates the kinase d) prevents phosphorylation of the inhibitory site of the kinase d) determines the substrate specificity of the kinase e) none of the above

d) determines the substrate specificity of the kinase page 10 cell cycle 1

30) Which of the following messenger molecules mediates the ripening of fruit? a) methane b) methylene c) ethane d) ethylene e) acetylene

d) ethylene

15) Photoisomerization of the rhodopsin cofactor, 11-cis retinal, results in which of the following? a) exchange of ATP for ADP-bound Gs, and activation of adenylyl cyclase b) exchange of GTP for GDP-bound Gs, and activation of adenylyl cyclase c) exchange of GTP for GDP-bound Go, and activation of phosphodiesterase d) exchange of GTP for GDP-bound Gt, and activation of phosphodiesterase e) exchange of GTP for GDP-bound Gt, and inhibition of guanylyl cyclase

d) exchange of GTP for GDP-bound Gt, and activation of phosphodiesterase

9) What are T-tubules? a) components of the sarcoplasmic reticulum b) modified endoplasmic reticulum c) triplet microtubules found in the centriole and basal bodies d) extensions of the plasma membrane e) none of the above

d) extensions of the plasma membrane

2) Which of the following is NOT a component of the basal lamina? a) laminin b) collagen c) proteoglycans d) fibronectin e) all of the above are components of the basal lamina

d) fibronectin

39) Which of the following cell-matrix junctions is formed by cell adhesion molecules that are associated with actin filaments? a) tight junctions b) adherens junctions c) desmosomes d) focal adhesions e) gap junctions

d) focal adhesions page 9 extracellular matrix

29) Which of the following is FALSE regarding the paracrine messenger, nitric oxide? a) it is enzymatically produced from arginine b) it is produced in endothelial cells c) it crosses cell membranes by simple diffusion d) it activates an adenylyl cyclase e) it inhibits smooth muscle contraction

d) it activates an adenylyl cyclase it activates guanylyl cyclase

17) What is the role of the troponin complex in striated muscle contraction? a) it activates myosin light chain kinase b) it transmits action potentials to myofibrils c) it opens calcium channels on the sarcoplasmic reticulum d) it binds calcium and moves tropomyosin off myosin binding sites e) it blocks myosin binding sites on actin filaments

d) it binds calcium and moves tropomyosin off myosin binding sites page 19 cytoskeleton 3

48) Which of the following kinesin proteins plays a key role in the Anaphase A process? a) kinesin 1 b) kinesin 4,10 c) kinesin 5 d) kinesin

d) kinesin 13 page 6 and 8 cell cycle 2

16) Which of the following events is mediated by a calcium-gated calcium channel? a) action potential generation b) action potential propagation c) neurotransmitter release d) muscle contraction e) extension of the lamellipodium

d) muscle contraction page 18 cytoskeleton 3

36) Most procaspases are activated by ... a) cytochrome C d) other caspases b) death signals e) none of the above c) kinases

d) other caspases

30. During the transport cycle of the Na-K ATPase, which of the following events causes the conformation change that transports SODIUM IONS OUT of the cell? a) ATP hydrolysis b) phosphorylation of a tyrosine residue c) phosphoryation of a serine residue d) phosphorylation of an aspartate residue e) dephosphorylation of an aspartate residue

d) phosphorylation of an aspartate residue

25) During cytokinesis, the orientation of the contractile ring is primarily determined by which of the following? a) orientation of the metaphase plate b) accumulation of gamma tubulin c) overlap of the interpolar microtubules d) position of the asters e) Earth's magnetic field

d) position of the asters

21) The nuclear envelope disintegrates during which phase of mitosis? a) telophase b) anaphase c) metaphase d) prometaphase e) prophase e) prophase

d) prometaphase page 2 cell cycle 2

19) Phosphorylation of tyrosine residues on receptor tyrosine kinases results in which of the following events? a) receptor dimerization b) accumulation of a soluble second messenger in the cytoplasm c) nuclear translocation of the receptor d) recruitment of signaling proteins to the plasma membrane e) all of the above

d) recruitment of signaling proteins to the plasma membrane

29) Which of the following events occurs immediately after GTP hydrolysis by elongation factor Tu (EF-Tu). a) binding of the complex to the A-site of the ribosome b) the formation of 2 or more correct Watson-Crick base pairs with the mRNA c) binding of the amino acyl t-RNA d) release of the amino acyl t-RNA? e) exchange of bound GDP for GTP

d) release of the amino acyl t-RNA?

21) Which of the following proteins does NOT participate in calcium homeostasis in the cell. a) calcium ATPase on the plasma membrane b) calcium ATPase on the smooth endoplasmic reticulum c) sodium-calcium antiporter on the plasma membrane d) sodium-calcium antiporter on the endoplasmic reticulum e) calcium binding proteins in the cytoplasm

d) sodium-calcium antiporter on the endoplasmic reticulum this is because they just store ca. have nothing really to do with na

50) What are T-tubules? a) Triplet microtubules found in the centriole and basal bodies b) branches of the endoplasmic reticulum shaped like the letter "T". c) specialized extensions of the sarcoplasmic reticulum d) specialized extensions of the striated muscle cell plasma membrane e) components of the sarcomere discovered by Thompson and colleagues

d) specialized extensions of the striated muscle cell plasma membrane

37) What is the ultimate fate of apoptotic cells? a) they aggregate in tissue to form scars b) they are processed to simple compounds by their own enzymes c) they remain quiescent until activation of G1-S Cdk d) they are consumed by macrophages e) they emerge in a parallel universe as components of anti-creatures

d) they are consumed by macrophages

41) Which of the following is TRUE regarding most kinesin motor proteins? a) they hydrolyze GTP and move toward the plus end of the actin filament b) they hydrolyze GTP and move toward the plus end of the microtubule c) they hydrolyze GTP and move toward the minus end of the microtubule d) they hydrolyze ATP and move toward the plus end of the microtubule e) they hydrolyze ATP and move toward the minus end of the microtubule

d) they hydrolyze ATP and move toward the plus end of the microtubule

46) Which of the following cell junctions does NOT include a cytoskeletal component? a) adherens junctions b) desmosomes c) hemidesmosomes d) tight junctions e) all cell junctions include cytoskeletal components

d) tight junctions adherens joins actin through cadherins desmosomes join int filaments through cadherins hemidesmosomes and focal adhesions join int fil to the basal lamina through integrins (cell-matrix junction)

4) During translation of a ER membrane protein, a signal recognition particle (SRP) binds to the ER signal sequence, and translation is arrested. Which of the following events causes translation of this protein to continue? a) phosphorylation of the SRP b) binding of the complex to the SRP receptor c) binding of molecular chaperones to the complex d) transfer of the ribosome to the ER translocator protein e) proper alignment of the appropriate stars

d) transfer of the ribosome to the ER translocator protein

2) In addition to displaying a mitochondrial signal sequence, proteins entering the mitochondrion must be ... a) phosphorylated b) glycosylated c) ubiquinated d) unfolded e) none of the above

d) unfolded

15) Tertiary structure is stabilized by which of the following? a) hydrogen bonds between elements of the amino acid backbone. b) hydrogen bonds between amino acid side chains c) van der Waals attractions between elements of the amino acid backbone. d) van der Waals attractions between hydrophobic amino acid side chains e) ionic interactions

d) van der Waals attractions between hydrophobic amino acid side chains

on which of the following cell mebranes would you expect to find inositol 1,4,5-trisphosphate receptors a. the plasma membrane b. the mitochondrial outer membrane c. the nuclear envelope d. the smooth endoplasmic reticulum e. the golgi complex

d, the smooth endoplasmic reticulum

activation of rhodopsin by photoisomeration of 11 cis retinol causes which of the following outcomes a. increase in cgmp levels, membrane depolarization b. decrease in cgmp, membrane depolatrization c. increase in cgmp, membrane hyyperpolarization d. decrease in cgmp, membrane hyperpolarization

which of the following best describes the orientation of an er protein containing an n terminal er omport signal sequence and 4 additional runs of 18 small non polar amino acids a. 5 transmembrane domains with carboxyl terminal in the er lumen b. 5 transmembrane domains with the carboxyl terminal in the cytosol c. 4 transmembrane domains with the carboxyl domains in the cytosol d. 4 transmembrane domains with the amino and carboxyl terminals on the same side of the membrane e. 4 transmembrane domains with the amino and carboxyl terminals on opposite side of the membrane

d. 4 transmembrane domains with the animo and carboxyl terminals on the same side of the membrane

Which of the following sarcomere proteins is found at the Z disc? a. tropomyosin b. troponin c. tropomodulin d. CapZ e. none of the above

d. CapZ

The term "interphase" refers to which of the following phase(s) of the cell cycle. a. G1 phase b. G1 phase + S-phase c. S-phase + G2 phase d. G1 phase + S phase + G2 phase e. G2 phase + M phase

d. G1 phase + S phase + G2 phase

A serious error of DNA replication would most likely arrest cells in which phase of the cell cycle? a. G1 phase b. S phase c. M phase d. G2 phase e. all phases

d. G2 phase

The substance in the cytoplasm of M-phase cells that promotes mitosis in cell-free extracts of Xenopus oocytes was originally called ... a. Momma's Powerful Force b. Maternal Procreation Factor c. Mammalian Prometaphase Factor d. Maturation Promoting Factor e. None of the above

d. Maturation Promoting Factor

which of the following proteins releases calcium from the sarcoplamic reticulum in response to muscle depolarization a. an m type calcium atpase b. a sodium calcium antiporter c. a voltage gated calcium channel d. calcium gated channel e. ip3 receptor

d. a caclium gated calcium channel

Which of the following proteins releases calcium from the sarcoplasmic reticulum in response to muscle depolarization? a. an M-type calcium ATPase b. a sodium-calcium antiporter c. a voltage-gated calcium channel d. a calcium-gated calcium channel e. an IP3 receptor

d. a calcium-gated calcium channel

which of the following messenger molecules does not signal through a nuclear receptor a. testosterone b. thyroxine c. cortisol d. acetylcholine e. all of the above

d. acetlycholine

what provides the force that drives protrusion of the leading eedge of a motile cell a. myosin I motors b. myosin II motors c. dyenin motors d.actin polyermization e. microtubule polyermization

d. actin polyermization

activation of the phosphatidylinositol 3 kinase pathway results in activation of which of the following enzymes a. adenylyl cyclase b. guanylyl cyclase c. phospholipase c beta d. akt kinase e. none of the above

d. akt kinase

During anaphase, the forces that drive movement of chromatids toward opposite spindle poles include all of the following except ... a. plus end depolymerization of kinetochore microtubules b. plus end directed kinesin motors acting on interpolar microtubules c. minus end directed dynein motors acting on aster microtubules d. all of the above provide the forces that drive chromosomal segregation e. none of the above provide the forces that drive chromosomal segregation

d. all of the above provide the forces that drive chromosomal segregation

50. Which of the following ATP-driven pumps can be made to run "backwards" and synthesize ATP? a. P-type pump c. ABC-type pump b. F/V-type pump d. all of these are reversible

d. all of these are reversible

What is "dynamic instability"? a. a synonym for the Bush Administration b. a new economic paradigm c. "Change that you cannot believe in" d. an essential property of microtubules

d. an essential property of microtubules

which of the following proteins is most concentrated at the leading edge of a motile cell a. myosin I b. myosin II c. formins d. arps e. all of the above are concentrated at the leading edge of a motile cell

d. arps

During cytokinesis, the orientation of the contractile ring is primarily determined by the location of the ... a. metaphase plate b. chromatids c. interpolar microtubules d. asters/centrosomes e. yin-yang axis

d. asters/centrosomes

during rtk signaling ligand binding results in receptor dimerization. which of the following events occurs next. a. assembly of the signaling complex b. synthesis of camp c. activation of the ras gtapse d. autophosphoryation of both receptors e. recruitment of other signaling proteins

d. autophosphorylation of both receptors

how does protein kinase a activate gene expression a. by phospohrylating creb binding protein b. by phosphorylating rna polyermase c. by phosphorylating creb protein in the cyctoplasm d. by phosphorylating creb protein in the nucleus

d. by phosphorylating the creb protein in the nucleus

in rod phoyoreceptors, light activated rhodopsin signal through the trimeric g protein 'transduction' resulting in the activation of which of the following enzymes a. adenylyl cyclase b. guanylyl cyclase c. camp phosphodiesterase d. cgmp phosphodiesterase e. protein kinase a

d. cgmp phosphodiesterase

the blockbuster drug viagra is an inhibitor of which of the following enzymes a. adenylyl cyclase b. guanylyl cyclase c. camp phosphodiesterase d, cgmp phosphodiesterase e. nitic oxide synthase

d. cgmp phosphodiesterase

which of the following actin accesory proteins binds to and destablizes actin filaments a. formin b. filamin c. profilin d. cofilin e. fimbrin

d. cofilin

which of the following actin accessory proteins binds to and destabilizes actin filaments a. profilin b. formin c. filamin d. cofilin e. fibbrin

d. cofilin

which of the following refers to the smc protein complex that gathers and organizes newly replicated dna into chromosomes a. gatherin b. compactin c. cohesin d. condesin

d. condesin

substained activation of protein kinase a often results in gene transcription. which of the following transcription factors is a target of a protein kinase a a. tat box binding protein b. stat proteins c. myc protein d. creb protein e. creb binding protein

d. creb protein

In rapidly dividing cells, MPF activity was observed to oscillate, with peak levels occurring at the G2 - M transition. The oscillatory component of the MPF complex was later shown to be which of the following proteins? a. cyclin dependent kinase 1 (Cdk1) b. cyclin dependent kinase 2 (Cdk2) c. cyclin A d. cyclin B e. Like I told you in my response to the last question ... MPF is not a protein!

d. cyclin B

A loss-of-function mutation of the p53 gene would result in ... a. increased biosynthesis of genes controlling S phase events b. decreased biosynthesis of genes controlling G1 phase events c. increased p21 expression leading to arrest of the cell cycle at G1 d. decreased p21 expression leading to unregulated entry into S phase e. decreased probability of replication of damaged DNA

d. decreased p21 expression leading to unregulated entry into S phase

The minus (-) end directed motor proteins that pull the spindle poles toward the plasma membrane are called ... a. kinesin 14 b. kinesin 5 c. kinesin 4/10 d. dynein e. myosin I

d. dynein

s cyclin proteins begine to accumulate during g1 phase. when does the concentration of s cyclin protein fall a. g1 phase b. s phase c. g2 phase d. early phase (mitosis) e. late m phase (cytokinesis)

d. early m phase (mitosis)

photoisomerization of 11 cis retinal bound to rhodopsin results in which of the following a. exchane of atp for adp bound gs, and activation of adenylyl cylclase b. exchange of gtp for gdp bound gs and activation of adenylyl cyclase c. exchange of gtp for gdp bound gs and activation of phospodiesterase d. exchange of gtp for gdp bound gt and activation of phosphodiesterase e. exchange of gtp for gdo bound gt and inhibition of guanylyl cyclase

d. eexchange of gtp for gdp bound gt and activation og phosphodiesterase

during pinocytosis, extracellualr fluid is delivered to which of the following compartments a. lysomes b. golgi apparaturs c. cytoplasm d. endosome e. all of the above

d. endosome

lathrin coated vesiclestransport proteins to which of the following target compartments a. cis golgi apparatus b. plasma membrane c. endoplasmic reticulum d. endosomes e. all of the aboe

d. endosome

what is dynamic instability a. asynonym for the bush admisitration b a new economic paradigm c. an essential property of actin filaments d. an essential property of microtubules

d. essential property of microtubules

During kinesin movement along a microtubule, which event triggers power stroke? a. hydrolysis of GTP b. hydrolysis of ATP c. dissociation of ADP d. exchange of ADP for ATP e. dissociation of Pi

d. exchange of ADP for ATP

during kinesin movement along a microtubule, which event triggers the power stroke a. hydrolysis of gtp b. hydrolysis of atp c. dissociation of adp d. exchange of adp for tp e. dissociation of pi

d. exchange of adp for atp

photoisomerization of the rhodopsin cofactor 11-cis retinal results in which of the following a. exchange of atp for adp bound Gs and activation of adenylyl cyclase b. exchange of gtp fpr gdp bound Gs and activation of adenylyl cyclase c. exchange of gtp for gdp bound Go and activation of phosphodiesterase d. exchange of gtp for gdp bound Gt and activation of phosphodiesterase e. exchange of gtp for gdp bound Gt and inhibition of guanylyl cylase

d. exchange of gtp for gdp bound Gt and activation of phosphodiesterase

a new drug increases the secretion of a hormone from cultured cells through the activation of a gpcr. pretreatment of the cells with cholera toxin increases the magnitude and duration of the response to the drug. this observation suggests that the drug is probably signaling through which of the following trimeric g proteins a. gq b. gt c. gi d. gs e. go

d. gs

which of the following trimeric g protein alpha subunits is activated by cholera toxin a. gq b. gi c. go d. gs e. gt

d. gs

activation of the protein kinases a (pka) signaling pathway does not involve which of the following events a. dissociation of the alpha subunit of Gs from the beta gamma subunit b. activation of adenyl cyclase c. dissociation of the regulatory subunit from the catalytic subunits of pka d. hydrolysis of cyclic amp by the regulatory subunit of pka e. exchange of gtp for gdp bound to Gs

d. hydrolysis of cyclic by the regulatory subunit of pka

How do survival factors prevent apoptosis? a. decreased synthesis of caspases b. increased degradation of caspases c. direct inhibition of caspases d. induction of Bcl-2 protein e. all of the above

d. induction of Bcl-2 protein

which of the following is false regarding the paracrine messenger nitric oxide a. it is enzymatically produced from arginine b. it is produced in endothelial cells c. it crosses cell membranes by simple diffusion d. it activated an adeenylyl cyclase

d. it activates an adenylyl cyclase

During apoptosis, how does cytochrome C get out of the mitochondrion? a. it aggregates to form clusters that are membrane permeable b. it unfolds with the help of chaparones and exits through the TOM complex c. by receptor mediated exocytosis d. it leaves through channels formed by BH123 proteins e. it doesn't leave the mitochondria

d. it leaves through channels formed by BH123 proteins

How does cytochrome C initiate apoptosis? a. it oxidizes cytoplasmic proteins b. it blocks oxidative phosphorylation c. it directly activates executioner procaspases d. it promotes the aggregation of initiator procaspases e. cytochrome C is a mitochondrial protein, and has nothing to do with apoptosis. Duh!

d. it promotes the aggregation of initiator procaspases

how does cytochrome c initiates apoptosis a. it promotes the aggregation of bh123 proteins in the outer membrane b. it aggregates to form channels in the outer mitochondrial membrane c. it directly activates executioner procaspases d. it promotes the recruitment of initiator procaspases e. none of the above

d. it promotes the recruitment of initiator procaspases

which of the following is an intermediate filament protein found in all cells a. keratin b. collagen c. vimentin d. lamin a

d. lamin a

raf, mek, and erk are members of which of the following kinase families a. janus kinases b. cyclin dependent kinases c. calcium calmodulin (CAM) kinases d. map kinases e. none of the above

d. map kinases

41. The closing of the Venus flytrap is triggered by which of the following ion channel types? a. voltage gated ion channels b. ligand-gated ion channels c. light-gated ion channels d. mechanically-gated ion channels e. fly-gated ion channels

d. mechanically-gated ion channels

What prevents pre-mature (involuntary) contraction of striated muscle? a. lack of ATP b. lack of calcium c. myosin light chain kinase d. myosin binding sites are blocked by topomyosin e. myosin binding sites are blocked by troponin complex

d. myosin binding sites are blocked by topomyosin

what prevents pre mature (involuntary) contraction of striated muscle a. lack of atp b. lack calcium c. myosin light chain kinase d. myosin binding sites are blocked by tropomyosin e. myosin binding sites are blocked by troponin complex

d. myosin binding sites are blocked by tropomyosin

Which of the following proteins is responsible for controlling the length of actin filaments in the sarcomere? a. topomyosin b. topomodulin c. capZ d. nebulin e. titin

d. nebulin

which of the following intermediate filaments is found in all animal cells a. keratins b. vimentin c. neurofilaments d. nuclear lamins e. all of the above are found in all animal cells

d. nuclear lamins

11. The peptidyl transferase reaction in the ribosome is catalyzed by which of the following? a. sequentially by ribosomal RNA, then ribosomal proteins b. sequentially by ribosomal protein, then ribosomal RNA c. a combination of ribosomal RNA and proteins d. only ribosomal RNA e. only ribosomal proteins

d. only ribosomal RNA

during g1 phase which of the following prevent entry into s phase when dna damage is present a. mtor b. cdh1 c. cdc2o d. p53 e. myc

d. p53

Which of the following toxins binds to and stabilizes actin filaments? a. cytochalasin B b. taxol c. colchicine d. phalloidin e. vinblastin

d. phalloidin

which of teh following toxins binds to and stablizes actin filaments a. colchicine b. taxol c. cytochalasin B d. phalloidin e. none of the above

d. phalloidin

which of the following compounds binds to actin filaments and is frequently used to as an affinty reagent for fluorescent labeling of the actin cytoskeletons a. colchicine b. cytochalasin c. taxol d. phalloidin e. vincristine

d. phalloidin

which of the following toxins binds to and stablize actin filaments a. cytochalasin B b. taxol c. colochicine d. phasllodin e. vinblastin

d. phalloidin

which of the following enzymes is not activated through g protein coupled receptor signaling a. adenylyl cyclase b. guanyly cyclase c. phospholipase c d. pi3 kinase e. all of the above

d. pi3 kinase

to be recruited to a phosphoinisitol 3, 4 5 triphospahte molecule on the plasma membrane a protein must display which of the following strucutrual features a. a src homolgy 2 domain b. a src homolgy 3 domain c. cyclic nucleotide binding domain d. pleckstrin homolgy domain e. a kinase domain

d. pleckstrin homology

which of the following signal sequence identifies a protein for nuclear import a. lys -asp- glu- leu - co2h b. ser-lys-leu-co2h c. h3n-met-meet-ser-val-phe-leu-leu-leu-val-gly-ile-leu-phe-trp-ala d.pro-pro-lys-lys-lys-arg-val e none of the above

d. pro-pro-lys-lys-lys-arg-val

Under conditions that support treadmilling of actin filaments, what would be the consequence of capping the actin filaments at the plus (+) end? a. catastrophe b. increased cell motility c. rapid polymerization of actin filaments d. rapid depolymerization of actin filaments e. none of the above

d. rapid depolymerization of actin filaments

under conditions that supoort treadmilling of actin filaments, what would be the consequence of capping the actin filaments at the plus end a. catatrophe b. increased cell motility c. rapid polymerization of actin filaments d. rapid depolymerization of actin filament e. none of the above

d. rapid depolymerization of actin filaments

Receptor tyrosine kinases require which of the following events for activation? a. proteolysis of the regulatory domain b. phosphorylation of the regulatory domain c. glycosylation of the regulatory domain d. receptor dimerization e. activation of a trimeric G protein

d. receptor dimerization

Most mitogens, growth factors and survival factors signal through ... a. G-protein linked receptors b. cyclic AMP c. cytoplasmic receptors d. receptor tyrosine kinases e. all of the above

d. receptor tyrosine kinases

Phosphorylation of tyrosine residues on receptor tyrosine kinases results in which of the following events? a. receptor dimerization b. accumulation of a soluble second messenger in the cytoplasm c. nuclear translocation of the receptor d. recruitment of signaling proteins to the plasma membrane e. all of the above

d. recruitment of signaling proteins to the plasma membrane

What is the smallest contractile unit in striated muscle cells? a. myofibril b. sarcophagus c. sarcoplasmic reticulum d. sarcomere e. actin filament

d. sarcomere

Un-capped actin filament "grow" (polymerize) at the plus (+) end. What happens at the minus end?

depolymerization

50) Which of the following cell-cell junctions is formed by cell adhesion molecules that are associated with intermediate filaments? a) desmosomes d) adherens junctions b) hemidesmosomes e) gap junctions c) tight junctions

desmosomes

Which of the following cell-cell junctions is formed by cell adhesion molecules that are associated with intermediate filaments?

desmosomes

In addition to the activation of the cyclin-dependent protein kinase, what is the role of the cyclin subunit?

determines the substrate specificity of the kinase

What is the role of the cyclin component of Cdk complexes (e.g., M-Cdk)?

determines the substrate specificity of the kinase

Unstained, living cells are best observed using which of the following microscopic techniques?

differential interference contrast

Which of the following microscopic techniques provides the highest resolution images of unstained, living cells?

differential interference contrast microscopy

Complete the following sentence. "Cytoplasmic dyneins are ..."

dimeric, minus (-) end directed microtubule motor proteins

Complete the following sentence. "Cytoplasmic dyneins are ..."

dimeric, minus end directed microtubule motor proteins

P-type pump

single polypeptide exclusively ions 1 ATP per cycle phos/dephos/cycle: aspartate Na+/K+ ATPase

ABC transporter

single polypeptide small molecules 2 atp/cycle flippases

hyper polarization phase is due to

slow inactivation kinetics of voltage gated potassium channels

All of the following, transport monovalent cations along their concentration gradient

sodium-calcium anitporter sodium-glucose symporter potassium channels

In epithelial cells, how is glucose transported across the apical membrane?

sodium-glucose symporter

Which of the following transport proteins is restricted to the apical membrane of epithelial cells?

sodium-glucose symporter

Which of the following proteins transports monovalent cations against their concentration gradient?

sodium-potassium ATPase

Which of the following is the calcium sensor that facilitates exocytotic release of neurotransmitter at the presynaptic terminal?

synaptotagmin

Which of the following proteins determines the packing density of microtubules in axons?

tau

signal through a "nuclear receptor"

testosterone thyroxine cortisol (not acetylcholine)

What are Okazaki fragments?

the DNA segments that comprise the lagging strand of DNA

The KDEL signal sequence, located near the C-terminus of a protein, identifies the protein for transport to which of the following compartments?

the ER

Which domain of the voltage gated potassium channel is forms the selectivity filter?

the P-segment

Which domain of the voltage gated potassium channel is forms the voltage sensor?

the S4 transmembrane alpha helix

nicotinic acetylcholine receptor

the alpha subunits bind acetylcholine

Which of the following is FALSE regarding nucleosomes? they contain hetero-octomeric histone complexes they include 147 base pairs of DNA the bound DNA is preferentially degraded by nucleases they control access to DNA

the bound DNA is preferentially degraded by nucleases

the channel cannot conduct protons

The aqueous channel of the aquaporin complex has a pair of key asparagine residues located almost halfway through along the channel. These residues form hydrogen binds with the oxygen atoms of a single water molecule, rendering it unavailable for additional hydrogen-bonding. Which of the following best describe the consequence of this structural feature?

the channel cannot conduct protons

Consider the biochemical pathway A C, where delta-G0 for A B ("reaction 1") is +55kJ/mole, and delta-G0 for BC ("reaction 2") is -45kJ/mole. For the combined reaction, which of the following statements best describes the equilibrium concentration of C?

the concentration of C for the combined reaction will be lower than the concentration of C for reaction 2

Which feature of the cyclin dependent kinase (Cdk) complex determines the substrate specificity of the kinase?

the cyclin subunit

Enzymes that mediate N-glycosylation are located in ...

the cytoplasm the ER lumen the Golgi

What is a "Stokes Shift"?

the difference between the peak absorbance and the peak emission wavelengths of a fluorochrome

What is the structural basis for the ion selectivity of the voltage gated potassium channel?

the distribution of carbonyl oxygen atoms along the ion channel favors potassium permeability

The observation that plasma membrane proteins mix after cell fusion provides evidence for...

the lateral movement of plasma membrane proteins

The numerical aperture describes what characteristic of a lens?

the light gathering ability

In a eukaryotic flagellum the bending of microtubules is driven by

the motor protein ciliary dynein

During kinesin movement along a microtubule, what happens immediately after nucleotide exchange?

the neck linker "zippers" onto the leading head

Which of the following events occurs during prometaphase?

disintegration of the nuclear envelope

After a myosin motor head has been "cocked" and is bound to the actin filament, which of the following events triggers the "power stroke"

dissociation of Pi

During kinesin movement along a microtubule, which event causes the neck linker to zipper onto the head domain- the power stroke? -hydrolysis of ATP -exchange of ADP for ATP -dissociation of Pi -hydrolysis of GTP -exchange of GDP for GTP

dissociation of Pi

During nuclear import, what happen IMMEDIATELY AFTER the binding of Ran-GTP to the nuclear import receptor?

dissociation of the cargo protein from the NIR

3) Which of the following species was chosen as a model organism for genetic analysis due, in part, to unusually large chromosomes? a) Arabidopsis thaliana b) Drosophila melanogaster c) Caenorhabditis elegans d) Danio rero e) None of the above

dmel

A group of secondary structural elements that fold together to form a spatially distinct tertiary conformation is called a ...

domain

When a cell displays the Delta ligand on the plasma membrane, what is this cell "saying" to the adjacent cells?

don't become a neuron

Which of the following species was chosen as a model organism for genetic analysis due, in part, to unusually large "polytene" chromosomes?

drosophila melanogaster

Many anti-cancer drugs target the microtubule cytoskeleton. Which of the following best describes this class of anti-cancer drugs?

drugs that disrupt the dynamic instability of microtubules

The minus (-) end directed motor proteins that pull the spindle poles toward the plasma membrane are called ...

dynein

23) The minus (-) end directed motor proteins that pull the spindle poles toward the plasma membrane are called ... a) myosin I b) myosin II c) dynein d) kinesin 5 e) none of the above

dynein they are dynin because they are going to the minu end

11) After a myosin motor head has been "cocked" and is bound to the actin filament, which of the following events triggers the "power stroke" a) ATP hydrolysis b) GTP hydrolysis c) binding of ATP d) binding of GTP e) dissociation of Pi

12) What is the function of gamma tubulin ring complexes? a) they stabilize the plus ends of microtubules b) they destabilize the plus ends of microtubules c) they stabilize the minus ends of microtubules d) they bind together the plus ends of microtubules e) they nucleate polymerization of microtubules

13) Many anti-cancer drugs target the microtubule cytoskeleton. Which of the following best describes this class of anti-cancer drugs? a) drugs that destabilize microtubules b) drugs that stabilize microtubules c) drugs that prevent microtubule polymerization d) drugs that promote microtubule polymerization e) drugs that disrupt the dynamic instability of microtubules

15) Potential anticancer drugs might include agents that do which of the following? a) prevent the polymerization of microtubules b) prevent the depolymerization of microtubules c) promote the depolymerization of microtubules d) inhibit GTP hydrolysis at the plus (+) end of microtubules e) drugs that have any of the above actions should be considered potential anticancer agents

17) During dynamic instability of microtubules, when does the "catastrophic" shortening of microtubules occur? a) when GTP levels are exhausted b) when ATP levels are exhausted c) when microtubules contact the plasma membrane d) when the ATP-bound form of G-actin falls below the critical concentration e) when the microtubule looses it's "GTP cap"

24) MPF refers to the substance(s) present in the cytosol of unfertilized Xenopus oocytes that is capable of driving multiple cycles of M phase and S phase in vitro. What is MPF? a) Mitotic Progress Facilitator b) Metaphase Promoting Factor c) Momma's Powerful Force d) Metaphysical Procreation Factor e) Maturation Promoting Factor

29) What is the role of the cyclin component of a cyclin-dependent protein kinase complex? a) it phosphorylates and activates the kinase b) it blocks the active site of the kinase c) it protects the kinase from ubquination d) it is a phosphatase e) it determines the substrate specificity of the kinase

3) Which of the following G proteins signals through cGMP phosphodiesterase in retinal rod & cone cells? a) Gs d) Gq b) Gi e) Gt c) Go

30) Which of the following kinases is responsible for phosphorylation and inactivation of M-Cdk? a) MAP kinase b) Akt kinase c) S-Cdk d) Cyclin inactivating kinase e) Wee1

36) Which of the following refers to the proteins that are cleaved by separase to release sister chromatids at anaphase? a) anaphase promoting complex (APC) b) cyclin B c) condensins d) separins e) cohesins

37) Which of the following refers to the phosphatase that activates M-Cdk to initiate M-phase? a) phosphatase B b) M phosphatase c) cdc6 d) cdc20 e) cdc25

38) What is the energy source that drives chromosomal segregation during anaphase A? a) The Force b) ATP hydrolysis c) GTP hydrolysis d) hydrolysis of cohesins e) kinetochore microtubule catastrophe

41) During cytokinesis, which of the following motor proteins closes the contractile ring? a) dynein b) kinesin c) dynamin d) myosin I e) myosin II

43) Some of the effects of growth factors are mediated through which of the following kinases? a) protein kinase A b) protein kinase C c) CAK d) Wee1 kinase e) Akt kinase

44) Complete the following sentence: Caspases are ... a) kinases b) phosphatases c) ubiquitin ligases d) scaffold proteins e) proteases

45) Apoptosis can be induced by which of the following? a) pro-caspase activation b) expression of some Bcl-2 family genes c) suppression of other Bcl-2 family genes d) release of cytochrome C from mitochondria e) all of the above

48) Complete the following sentence: The anti-apoptotic protein, Bcl2, prevents apoptosis by ... a) returning cytochrome C to the mitochondrion b) promoting the aggregation of "BH123" proteins c) promoting the aggregation of "BH3 only" proteins d) preventing the aggregation of "BH3 only" proteins e) a mechanism that is not listed above

9) Which of the following is TRUE regarding dynein motor proteins? a) they hydrolyze GTP and move toward the minus (-) end of the microtubule b) they hydrolyze GTP and move toward the plus (+) end of the microtubule c) they hydrolyze ATP and move toward the plus (+) end of the actin filament d) they hydrolyze ATP and move toward the plus (+) end of the microtubule e) they hydrolyze ATP and move toward the minus (-) end of the microtubule

After a myosin motor head has been "cocked" and is bound to the actin filament, which of the following events triggers the "power stroke" a) ATP hydrolysis b) GTP hydrolysis c) binding of ATP d) binding of GTP e) dissociation of Pi

Apoptosis can be induced by which of the following? a) release of cytochrome C from mitochondria b) pro-caspase activation c) aggregation of BH123 proteins d) loss of survival factor signaling e) all of the above

Complete the following sentence: The anti-apoptotic protein, Bcl2, prevents apoptosis by ... a) returning cytochrome C to the mitochondrion b) promoting the aggregation of "BH123" proteins c) promoting the aggregation of "BH3 only" proteins d) preventing the aggregation of "BH3 only" proteins e) a mechanism that is not listed above

During cytokinesis, which of the following motor proteins closes the contractile ring? a) dynein b) kinesin c) dynamin d) myosin I e) myosin II

During endosomal maturation, there is a gradual decline in which of the following characteristics? a) the size of the endosome b) the density of the endosome c) the calcium concentration of the endosome d) the number of intralumenal vesicles e) the pH of the endosome

During the transport cycle for the sodium-potassium ATPase, which event occurs immediately after dephosphorylation of the critical aspartate residue? a) transport of 2 sodium ions from the extracellular compartment to the cytosolic compartment b) transport of 3 sodium ions from the extracellular compartment to the cytosolic compartment c) transport of 3 sodium ions from the cytosolic compartment to the extracellular compartment d) transport of 3 potassium ions from the extracellular compartment to the cytosolic compartment e) transport of 2 potassium ions from the extracellular compartment to the cytosolic compartment

MPF refers to the substance(s) present in the cytosol of Xenopus oocytes that is capable of driving multiple cycles of M phase and S phase in vitro. What is MPF? a) Momma's Powerful Force b) Metaphase Perturbation Factor c) Mitotic Progress Facilitator d) Metaphysical Procreation Factor e) Maturation Promoting Factor

Potential anticancer drugs might include agents that do which of the following? a) prevent the polymerization of microtubules b) prevent the depolymerization of microtubules c) promote the depolymerization of microtubules d) inhibit GTP hydrolysis at the plus (+) end of microtubules e) drugs that have any of the above actions should be considered potential anticancer agents

Some of the effects of growth factors are mediated through which of the following kinases? a) protein kinase A b) protein kinase C c) CAK d) Wee1 kinase e) Akt kinase

The Ras GTPase participates in which of the following signaling pathways? a) mTOR pathway d) phospholipase Cb b) PI3 kinase pathway e) MAP kinase pathway c) JAK kinase pathway

What is the function of cdc25? a) it is the kinase that phosphorylates cdk1 at the activating site b) it is the kinase that phosphorylates cdk1 at the inhibitory site c) it is a component of APC d) it is the protease that inactivates SMC proteins e) it is the phosphatase that dephosphorylates cdk1 at the inhibitory site

What is the role of the cyclin component of a cyclin-dependent protein kinase complex? a) it phosphorylates and activates the kinase b) it blocks the active site of the kinase c) it protects the kinase from ubquination d) it is a phosphatase e) it determines the substrate specificity of the kinase

Which mode of representation of the tertiary structure of a protein provides the most information about the location and orientation of secondary structural elements? a) water accessible surface model b) alpha trace model c) ball and stick model d) filled structural model e) schematic / ribbon model

Which of the following is FALSE regarding collagen? a) it is the most abundant protein in mammals b) every third amino acid is a glycine c) it is a trimeric, coiled coil. d) vitamin C is required for biosynthesis e) all of the above are TRUE regarding collagen

Which of the following is FALSE regarding transport of proteins into the mitochondria. a) the proteins must display an N-terminal mitochondrial signal sequence (NTMSS) b) the protein must be delivered in the unfolded state c) the protein binds via its NTMSS to a receptor component of the TOM complex d) after TOM and TIM align, the protein passes across both membranes into the matric e) the process is powered entirely by the pH gradient across the inner membrane

Which of the following is TRUE regarding dynein motor proteins? a) they hydrolyze GTP and move toward the minus (-) end of the microtubule b) they hydrolyze GTP and move toward the plus (+) end of the microtubule c) they hydrolyze ATP and move toward the plus (+) end of the actin filament d) they hydrolyze ATP and move toward the plus (+) end of the microtubule e) they hydrolyze ATP and move toward the minus (-) end of the microtubule

Which of the following is phosphorylated by the M-Cdk complex? a) p53 b) securin c) nuclear lamin B d) p21 e) all of the above are substrates for M-Cdk

Which of the following is/are TRUE regarding the role of the Rab GTPase in vesicular transport? a) It becomes associated with the source membrane prior to vesicle formation b) It identifies the target compartment of the vesicle c) it directs the transport machinery to deliver the vesicle to the target compartment d) It binds to tethering proteins on the surface of the target compartment e) all of the above is TRUE regarding Rab proteins

Which of the following kinases is responsible for phosphorylation and inactivation of M-Cdk? a) MAP kinase d) Cyclin Inactivating Kinase (CIK) b) Akt kinase e) Wee1 c) S-Cdk

Which of the following monomeric G-proteins is involved in remodeling of the actin cytoskeleton? a) Ras b) Ran c) Rab d) Rob e) Rho

Which of the following proteins is required to sustain APC activity during G1? a) cyclin D d) p53 b) Rb e) cdh1 c) cdc25

Which of the following proteins is/are NOT (an) ABC transporter(s)? a) bacterial permeases b) cystic fibrosis transmembrane conductance regulator c) phospholipid "flippases" d) multidrug resistance proteins e) all of the above are ABC transporters

Which of the following proteins promotes the depolymerization of actin filaments a) troponin b) severin c) depolymin d) profilin e) cofilin

Which of the following proteins serves as the plus (+) end capping protein of actin filaments in striated myocytes? a) tropomodulin b) tropomyosin c) troponin d) tropomyelin e) CapZ

Which of the following refers to the phosphatase that activates M-Cdk to initiate M-phase? a) phosphatase B b) M phosphatase c) cdc6 d) cdc20 e) cdc25

Which of the following refers to the proteins that are cleaved by separase to release sister chromatids at anaphase? a) anaphase promoting complex (APC) b) cyclin B c) condensins d) separins e) cohesins

Which of the following statements regarding ubiquitin-mediated proteolysis is FALSE? a) Ubiquitin activation requires ATP hydrolysis b) The first ubiquitin molecule is attached to the epsilon amino group of a lysine residue on the target protein c) A chain of ubiquitin molecules directs the target protein to the 20S proteasome d) Ubiquitin is not degraded by the 20S proteasome e) All of the above are true regarding ubiquitin-mediated proteolysis

1) Which of the following is NOT one of the 5 Essential Characteristics of All Living Cells? a) Capable of protein synthesis b) Capable of autonomous replication c) Capable of regulated metabolic activity d) Contain nucleic acid that encodes at least one complete copy of a genome e) All of the above are among the 5 essential characteristics

e) All of the above are among the 5 essential characteristics

11) Which of the following proteins serves as the plus (+) end capping protein of actin filaments in striated myocytes? a) tropomodulin b) tropomyosin c) troponin d) tropomyelin e) CapZ

e) CapZ page 14 cytoskeleton 3

12) MPF refers to the substance(s) present in the cytosol of Xenopus oocytes that is capable of driving multiple cycles of M phase and S phase in vitro. What is MPF? a) Momma's Powerful Force b) Metaphase Perturbation Factor c) Mitotic Progress Facilitator d) Metaphysical Procreation Factor e) Maturation Promoting Factor

e) Maturation Promoting Factor page 8 cell cycle 1

9) Which of the following monomeric G-proteins is involved in remodeling of the actin cytoskeleton? a) Ras b) Ran c) Rab d) Rob e) Rho

e) Rho page 12 cytoskeleton 3 (the only one involved with actin)

23B) Which of the following kinases is responsible for phosphorylation and inactivation of M-Cdk? a) MAP kinase Kinase (CIK) b) Akt kinase cycle 1 c) S-Cdk d) Cyclin Inactivating e) Wee1

e) Wee1 page 18 cell

20) Cyclin B (M-cyclin) levels rise throughout S-phase to peak early in G2-phase. However, M-phase does not begin until after G2-phase. Which of the following enzymes prevents premature entry into M-phase? a) cdk1 b) cdk2 c) CAK d) cdc25 e) Wee1

e) Wee1 page 18 cell cycle 1

46) What provides the force that drives protrusion of the leading edge of a motile cell? a) myosin I motors b) myosin II motors c) dynein motors d) microtubule polymerization e) actin polymerization

e) actin polymerization actin acts at the leading edge

38) Apoptosis can be induced by ... a) pro-caspase activation b) expression of some Bcl-2 genes c) suppression of other Bcl-2 genes d) release of cytochrome C from mitochondria e) all of the above

e) all of the above

27) Which of the following statements is FALSE regarding the immunoglobulin molecule? a) it is a heterotetramer composed of two light chains and two heavy chains b) there are two antigen binding domains c) the antigen binding domain(s) include elements of both the light and heavy chains d) the light and heavy chains are stabilized by disulfide bonds e) all of the above are TRUE regarding the immunoglobulin domain

e) all of the above are TRUE regarding the immunoglobulin domain

24) During anaphase, the forces that drive movement of chromatids toward opposite spindle poles include which of the following? a) plus end depolymerization of kinetochore microtubules b) plus end directed kinesin motors acting on interpolar microtubules c) minus end directed dynein motors acting on aster microtubules d) two of the above provide the forces that drive chromosomal segregation e) all of the above provide the forces that drive chromosomal segregation

e) all of the above provide the forces that drive chromosomal segregation

24) Which of the following messenger molecules does NOT signal through a soluble (also called "nuclear") receptor? a) testosterone b) cortosol c) thyroxine d) estrogen e) all of the above signal through soluble receptors

e) all of the above signal through soluble receptors

6) Which of the following proteins promotes the depolymerization of actin filaments a) troponin b) severin c) depolymin d) profilin e) cofilin

e) cofilin page 11 cytoskeleton 3

23) Which of the following is in correct order of decreasing bond strength in AQUEOUS MEDIUM? a) covalent bond > ionic bond > van der Waals > hydrogen bond b) covalent bond > ionic bond = van der Waals > hydrogen bond c) covalent bond > hydrogen bond > ionic bond > van der Waals d) covalent bond > ionic bond = hydrogen bond > van der Waals e) covalent bond > ionic bond > hydrogen bond > van der Waals

e) covalent bond > ionic bond > hydrogen bond > van der Waals

43) For myosin motors, which event causes release of the actin filament? a) binding of GTP d) hydrolysis of ATP b) binding of ATP e) dissociation of Pi c) hydrolysis of GTP

e) dissociation of Pi

10) Which small GTPase is responsible for the release of clathrin-coated vesicles from the source membrane? a) Ran GTPase b) Rab GTPase c) Ras GTPase d) Rac GTPase e) dynamin

e) dynamin

42) During kinesin movement along a microtubule, which event causes the "power stroke"? a) hydrolysis of GTP b) hydrolysis of ATP c) dissociation of ADP d) dissociation of Pi e) exchange of ADP for ATP

e) exchange of ADP for ATP Exchange of ADP for ATP shifts the "neck linker" forward (power stroke), swinging the ADP-bound head domain forward

12) What is the role of the tropomyosin in striated muscle contraction? a) it activates myosin light chain kinase b) it binds calcium c) it transmits action potentials to myofibrils d) it opens calcium channels on the sarcoplasmic reticulum e) it blocks myosin binding sites on actin filaments

e) it blocks myosin binding sites on actin filaments

4) What is the role of cyclin in the Cdk complex? a) it is a ubiquitin ligase b) it is a cdk inhibitor c) it phosphorylates the cdk d) it dephosphorylates the cdk e) it determines the substrate specificity of the complex

e) it determines the substrate specificity of the complex

26) What is the function of cdc25? a) it is the kinase that phosphorylates cdk1 at the activating site b) it is the kinase that phosphorylates cdk1 at the inhibitory site c) it is a component of APC d) it is the protease that inactivates SMC proteins e) it is the phosphatase that dephosphorylates cdk1 at the inhibitory site

e) it is the phosphatase that dephosphorylates cdk1 at the inhibitory site page 18 cell cycle 1

18) Receptor tyrosine kinases ALWAYS require which of the following events for activation? a) activation of a trimeric G protein b) activation of a small (monomeric) G protein c) phosphorylation of the regulatory domain d) dephosphorylation of the regulatory domain e) receptor dimerization

e) receptor dimerization

37) What is a "Stokes Shift"? a) a component of the gear box in a 1957 Chevy Bellaire b) a dance move developed by Fred Astaire and Ginger Stokes Rogers c) a gravitational anomaly in the Crab Nebula d) a critical step during the formation of a Bose-Einstein condensate e) the difference between the peak absorbance and emission wavelengths of a fluorochrome

e) the difference between the peak absorbance and emission wavelengths of a fluorochrome

32) How does the Notch receptor signal to the nucleus a) through Gq b) through MAP kinase c) through the JAK-STAT pathway d) through the PKA pathway e) through a proteolytic fragment of the receptor

e) through a proteolytic fragment of the receptor

7) Which of the following best describes the orientation of a protein in the ER membrane that contains an N-terminal ER signal sequence AND two internal hydrophobic domains? a) three transmembrane alpha helices with N-terminal in the ER lumen b) three transmembrane alpha helices with N-terminal in the cytosol c) two transmembrane alpha helices with N-terminal in the cytosol d) two transmembrane alpha helices with C-terminal in the cytosol e) two transmembrane alpha helices with N-terminal and C-terminal on same side of ER membrane

e) two transmembrane alpha helices with N-terminal and C-terminal on same side of ER membrane

27. Mature eucaryotic messenger RNA molecules contain a long polyadenosine "tail" at the 3' end. What is the purpose of 3' polyadenylation? a. It contributes to the stability of the mRNA b. It identifies the molecule as a messenger RNA c. It is required for transport through the nuclear pore complex d. It's length determines the half life of the mRNA e. All of the above

e. All of the above

1. Which of the following is FALSE regarding the ribosome? a. It is composed of two ribonucleoprotein complexes b. Two thirds of the mass of a ribosome is RNA c. Most of the catalytic functions of the ribosome are carried out by RNA d. It assembles only after mRNA is bound to the small subunit e. All of the above are TRUE regarding the ribosome

e. All of the above are TRUE regarding the ribosome

20. Which of the following is NOT considered to be part of the endomembrane system? a. nuclear envelope b. endoplasmic reticulum c. Golgi complex d. plasma membrane e. All of the above are considered to be part of the endomembrane system.

e. All of the above are considered to be part of the endomembrane system.

In early anaphase, APC is activated by cdc20. During G1, when cdc20 is depleted, APC activity is maintained by which of the following proteins? a. p53 b. Rb c. p21 d. G1-Cdk e. Hct1

e. Hct1

what is p27 a. a component of the pre-initation complex b. a component of the pre-intiation complex c. a cyclin d. a cyclin dependent kinase e. a cdk inhibitor

e. a cdk inhibitor

a dense region of the plasma membrne that has attracted clathrin coat proteins is called a. a lipid raft b. a clathrin raft c. a clathrisome d. a clathrin pit e. a coated pit

e. a coated pit

during delta notch signaling a factor is generates in the target cell which enters the nucleus and alters gene expression. what is the factor a. protein kinase a b. a stat complex c. creb d. an intermalized fragement of delta e. a proteolytic fragment of notch

e. a proteolytic fragment of notch

what provides the force that drives protrusion of the leading edge of a motile cell a. myosin I motors b. myosin II motors c. dynein motors d. microtubule polymerization e. actin polymerization

e. actin polymerization

Apoptosis can be induced by ... a. pro-caspase activation b. expression of certain Bcl-2 genes c. suppression of certain Bcl-2 genes d. release of cytochrome C from mitochondria e. all of the above

e. all of the above

cop 1 vesicles transport er proteins from which of the following compartemnts a. golgi cisternae b. trans golgi network c. vesicular tubular cluster d. cis golgu network e. all of the above

e. all of the above

mitochondrial porteins encoded by the nuclear genome are transported into the mitochondrion only when they .... include an n terminal mitochondrial signal sequence b. are unfolded c. are bound to a transport receptor ont he outer membrane d. are accompanied by chaperone proteins e. satisfy all of the above criteria

e. all of the above

the specificity of which of the following cell signaling mechanism is primarily dependent upon the availability of specifc receptors on the target cell a. endocrine signaling b. synaptic transmission c. contact dependent signaling d. paracrine signaling e. all of the above

e. all of the above

what goes on the in the gogli complex a. n type glycosylation is completed b. o type glycosylation is completed c. proteolytic activity d. proteins are packaged into approprite vesicles e. all of the above

e. all of the above

which of the following contains material destined for delivery to the lysosome a. multivescular bodies b. autophagosomes c. phagosomes d. late endosome e all of the above

e. all of the above

34. Which of the following is NOT involved in DNA replication of the lagging strand? a. DNA polymerase b. single strand binding proteins c. primase d. sliding clamp e. all of the above are involved in DNA replication at the lagging strand

e. all of the above are involved in DNA replication at the lagging strand

Which of the following is NOT required for the complete activation of M-Cdk? a. binding of cyclin B b. activation of Cdc25 c. phosphorylation of M-Cdk at the stimulatory site d. dephosphorylation of M-Cdk at the inhibitory site e. all of the above are required for full activation of M-Cdk

e. all of the above are required for full activation of M-Cdk

during anaphase the forces that drives the movement of chromatids toward the opposite spindle include which of the following a. plus end depolymerization of kinetochore microtubules b. plus end directed kinesin motors actin on interpolar microtubules c. minus end directed ynein motors acting on aster microtubules d. two of the above provide forces that drives chromosomal segregation e. all of the above provide forces that drives chromosomal segregation

e. all of the above provide forces the drive chromosomal segregation

some of the effects of growth factors are mediated through which of the kinases a. protein kinase A b. protein kinase c c. cak d. wee1 kinase e. akt kinase

e. alt kinase

what is the role of the troponin complex in striated muscle contraction a. activates myosin light chain kinase b. blocks myosin binding sites on actin filaments c. transmits action potentials to myofibrils d. open calcium channels on the sarcoplasmic reticulum e. binds calcium and releases tropomyosin

e. binds calcium and releases tropomyosin

18. How does the enzyme Telomerase prevent the progressive loss of DNA during replication? a. by providing a 3' hydroxyl on the leading strand b. by providing a 3' hydroxyl on the lagging strand c. by cleaving the 3" overhang at the telomere d. by stabilizing the polymerase at the telomere e. by adding tandem repeat sequences at the telomere

e. by adding tandem repeat sequences at the telomere

during vesicle formations adaptins bind first to which of the following proteins a. other adaptins b. adaptins receptors c. clathrin d. rabs e. cargo receptors

e. cargo receptors

which of the following refers to the phophatase that activates m cdk to initiate m phase a. phosphatase b b. m phosphatse c. cdc 6 d. cdc20 e. cdc25

e. cdc25

which of the following refers to the proteins that are ceaved by separase to release sister chromatids at anaphase a. anaphase promoting complex b. cyclin b c. condensins d. separins e. cohesins

e. cohesin

after a myosin motor head has been cocked and is to the actin filament wehich of the following events triggers the power stroke a. atp hydrolysis b. gtp hydrolysis c. binding of atp d. binding of gtp e. dissociation of pi

e. dissociation of pi

for myosin motors, which even t occurs immediately before the power stroke a. hydrolysis of gtp b. hydrolysis of atp c. dissociation of adp d. exchange of adp for atp e. dissociation of pi

e. dissociation of pi

potential anticancer drugs might include agents that do which of the following a. prevent the polymerization of microtubules b. prevent the depolymerization of microtubule c. promote the depolymerization of microtubules d. inhibit gtp hydrolysis at the plus end of the microtubule e. drugs that have any of the above actions ahould be considered potential anticancer agent s

e. drugs that have any of the above should be considered potential anticancer agent s

during kinesin movement along a microtubule, which event causes the neck linker to 'zipper onto the head domain' i.e. the power stroke a. hydrolysis of gtp b. hydrolysis of atp c. dissociation of adp d. dissociation of pi e. exchange of adp for atp

e. exchange of adp for atp

nuclear lamins are members of which protein class a. actin binding proteins b. neurofilament proteins c. microtubule binding proteins d. nuclear pore complex proteins e. intermediate filament proteins

e. intermediate filament proteins

39. Transport of ions across cell membranes occurs most rapidly through ... a. P-type pump b. F/V-type pump c. ABC-type pump d. symporter e. ion channel

e. ion channel

what is the role of cyclin in the cdk complex a. it is a ubiquitin ligase b. it is a cdk inibitor c. it phosphorylates the cdk d. it dephospholrylates the cdk e. it determines the substrate specificity of the complex

e. it determines the substrate specificity of the complex

what is the role of the cyclin component of a cyclin dependent protein kinase complex a. it phosphorylates and activates the kinase b. it blocks the active site of the kinase c. it protects the kinase from ubquination d. it is a phosphatase e. it determines the substrate speecificity of the kinase

e. it determines the substrate specificity of the kinase

Epidermolysis bullosa simplex is a genetic disease caused by a mutation in which of the following? a. actin b. a-tubulin c. b-tubulin d. g-tubulin e. keratin

e. keratin (intermediate filament protein)

mpf refers to the substance present in the cytosol of unfertilized xenopus oocytes that is capable of driving multiple cycles of m phase and s phase in vitro. what is mpf a. mitotic progress facilitator b. metaphase promoting factor c. momma's power force d. metaphysical procreation factor e. maturation promoting factor

e. maturation promoting factor

Constriction of the contractile ring during cytokinesis is driven by ... a. dynein b. kinesin 5 c. myosin I d. none of these e. myosin II

e. myosin II

during cytokinesis which of the follwoing motor proteins closes the contractile ring a. dynein b. kinesin c. dynanmin d. myosin e. myosin II

e. myosin II

which of the following best describes the microtubule structure of the axoneme of spermatozoa a. nine sets of singlet microtubules surrounding 2 doublet microtubules b. nine sets of doublet microtubules surrounding 1 singlet microtubules c. nine sets of doublet microtubules surrounding 2 singlet microtubules d. nine sets of triplet microtubules surrounding one singlet microtubule e. nine sets of triplet microtubuules surrounding 2 singlet microtubules

e. nine sets of triplet microtubules surrounding 2 singlet microtubules

which of the following does not occur after photoactivation of rhodopsin in the retina a. cgmp levels increase b. sodium channel open c. the cell is depolarized d. all of the above e. none of the above

e. none of the above

19. Which of the following transport monovalent cations AGAINST their concentration gradients ? a. potassium leak channels b. sodium-calcium antiporter c. sodium-glucose symporter d. voltage-gated sodium channels e. none of the above

e. none of the above pay attention to the wording

how does the notch receptor signal to the nucleus a. through gq b. through map kinase c. through the jak stat pathway d. through the pka pathway e. none of the above

e. none the above

the anit apoptotic protein bcI2 prevents apoptosis by.... a. returning cytochrome C to the mitochondrion b. promoting the aggregation of BH123 proteins c. promoting the aggregation BH3 only proteins d. preventing the aggregation of BH3 only proteins e. a mechanism that is not list above

e. not listed above

which of the following signaling enzymes creates sites on the plasma membrane for the recruitment and activation of protein kinase c a. pi3 b. grk kinase c. adenylyl cyclase d. guanylyl cyclase e. phopspholipase c

e. phospholipase c

32. What is the main difference between eucaryotic introns and procaryotic introns? a. eucaryotic introns are much larger b. procaryotic introns are A-T rich c. eucaryotic introns are A-T rich d. eucaryotic introns are G-C rich e. procaryotes do not have introns

e. procaryotes do not have introns

Caspases are ... a. kinases b. phosphatases c. ubiquitin ligases d. scaffold proteins e. proteases

e. proteases

which small gtpase is often activated during mitogen signaling a. rad b. rac c. rab d. ran e. ras

e. ras

the directionality of protein transport across the nuclear pore complex is due to which of the following a. direction of the atp gradient b. direction of the gtp gradient c. restriction of ran gap to the nuclear compartment d. restriction of ran gef to the cytosolic compartment e. restriction of ran gef to the nuclear compartment

e. restriction of ran egef to the nuclear compartment

47. Which of the following is NOT a phosphoglyceride? a. phosphatidyl choline b. phosphatidyl serine c. phosphatidyl ethanolamine d. phosphatidyl inositol e. sphingomyelin

e. sphingomyelin

23. The changes in ion permeability of the axonal membrane that give rise to the action potential were first determined using which model organism? a. mouse b. fly c. worm d. cougar e. squid

e. squid

What is the function of the centrioles? a. they sense the earth's magnetic field b. they nucleate microtubules c. they bind to the Golgi apparatus d. they are essential for mitosis e. their function is not known

e. their function is not known

what is the function of centrioles a. they sense the earth magentic field b. they nucleate microtubules c. they bind to the golgi apparatus d. they are essential for mitosis e. their function is not known

e. their function is not known

which of the following is true regarding dynein motor proteins a. they hydrolyze gtp and move toward the minus end of the microtubule b. they hydrolyze gtp and move toward the plus end of the microtubule c. they hydrolze atp and move toward the plus end of actin filament d. they hydrolyze atp and move toward the plus end of the microtubule e. they hydrolyze atp and move toward the minus end of the microtubule

e. they hydrolyze atp and move toward the minus end of the microtubule

How does the Notch receptor signal to the nucleus a. through Gq b. through MAP kinase c. through the JAK-STAT pathway d. through the PKA pathway e. through a proteolytic fragment of the receptor

e. through a proteolytic fragment of the receptor

what is the term for the movement of vesicles formed at the apical membrane to fuse weith the basolateral membrane of epithelial cells a. endocytosis b. exocytosis c. retrocytosis d, basocytosis e. transcytosis

e. transcytosis

when does catastrophe occur a. ewhen a microtubule contacts the plasma membrane b. when the gtp bound form of a tubulin dimer falls below the critical concentration c. when microtubules reach a certain age d. when wtp leveeeels are exhausted e. when a microtubule looses its gtp cap

e. when a microtubules looses it gtp cap

Which of the following events occurs during Wnt signaling? a. the Ras oncogene activates the MAPK cascade b. a gene regulatory protein is produced by selective proteolysis c. Janus kinases (JAKs) phosphorylate STAT proteins d. the Type 1 receptor phosphorylates Smad 2/3 e. β-catenin accumulates and enters the nucleus

e. β-catenin accumulates and enters the nucleus

the alpha helix

each turn of the helix involves 3.6 amino acid residues the amino acid side chains are oriented outward from the axis of the helix some are amphipathic

In procaryotes, all amino acyl tRNAs that enter the A-site of the ribosome are accompanied by which of the following?

elongation factor TU (EF-Tu)

Supportive tissues such as bone derive their strength from

extracellular matrix

which of the folllowing is flase regarding tubulin dimers a. they are composed of alpha and beta subunits b. both the alpha and beta subunits binds gtp c. only the beta subuint can hydrolyze its bound nucleotide d. the beta subuint is always exposed at the plus end of the microtubule e. none of the above f. all of the above are true

f. all of the above are true

What does the dynamin GTPase do?

facilitates membrane fusion to release clathrin coated vesicles

Is the following statement True or False? "Mitochondrial proteins encoded by the nuclear genome are transported into the mitochondrion only when they are properly folded prior to transport."

false

Is the following statement True or False? Protein kinases always activate their substrate phosphoproteins.

false

Is the following statement True or False? The complexity of an organism is directly related to the size (number of base pairs) of its genome.

false

Formation of PI(3,4,5)P3 by PI3 kinase results in the recruitment of proteins that possess which of the following?

pleckstrin homology (PH) domain

To be recruited to a phosphoinositol 3,4,5-trisphosphate molecule on the plasma membrane, a protein must display which of the following structural features?

pleckstrin homology (PH) domain

Complete the following sentence. " Most kinesins are ..."

plus (+) end directed microtubule motor proteins

During anaphase, the forces that drive movement of chromatids toward opposite spindle poles

plus end depolymerization of kinetochore microtubules plus end directed kinesis motors acting on inter polar microtubules minus end directed dyne motors acting on aster microtubules

During anaphase, the forces that drive movement of chromatids toward opposite spindle poles include which of the following?

plus end depolymerization of kinetochore microtubules plus end directed kinesis motors acting on interpolar microtubules minus end directed dyne motors acting on aster microtubules

Complete the following sentence. " Most kinesins are ..."

plus end directed microtubule motor proteins

two waves in phase

positive interference (bright)

For which of the following ions is the intracellular concentration typically higher than the extracellular concentration?

potassium

The resting membrane potential of approximately -70 mV is due to the selective permeability of the plasma membrane to which of the following ions?

potassium

The resting potential of the plasma membrane of an excitable cell is primarily due to the selective permeability of the membrane to which of the following ions?

potassium

The resting potential of the plasma membrane is primarily due to selective permeability of the membrane to which of the following ions?

potassium ions

The membrane potential of an excitable membrane is primarily determined by which of the following proteins/complexes?

potassium leak channels

Potential anticancer drugs might include agents that do which of the following?

prevent the polymerization of microtubules prevent the depolymerization of microtubules promote the depolymerization of microtubules inhibit GTP hydrolysis at the plus (+) end of microtubules

Which of the following is NOT a component of the basal lamina

fibronectin

occur during M phase of the cell cycle?

fixation of kinetochore microtubules chromosomal migration assembly of the spindle complex cytokinesis

Vinculin, together with Talin dimers, couple integrin dimers to the actin cytoskeleton in which of the following cell-matrix junctions?

focal adhesions

cadherins

form homophilic interactions members of the catenin protein family link them to cytoskeletal proteins exclusively form cell-cell junctions

Vesicular-tubular complexes are ...

formed by fusion of COP2 vesicles

gap junctions

formed by proteins called connexions six protein subunits form a single connexion hemichannel connexion hemichannels on adjacent cells associate to form the functional gap junction calcium ions and small metabolites can pass through gap junctions

Which of the following protein complexes is capable of nucleating actin filaments?

formin dimers

Which of the following proteins complexes can nucleate actin polymerization in the absence of existing actin filament

formin dimers

Which of the following initiates microtubule polymerization?

gamma tubules ring complexes

Potential anticancer drugs might include agents that do which of the following?

prevent the polymerization of microtubules prevent the depolymerization of microtubules promote the depolymerization of microtubules inhibit GTP hydrolysis at the plus (+) end of microtubules

The anti-apoptotic protein, Bcl2, prevents apoptosis by

preventing the aggregation of BH123, Bax and Bak, proteins

Which of the following is the largest glycosylaminoglycan (GAG)?

hyaluronan

Elements of secondary structure are stabilized primarily by ...

hydrogen bonds

The alpha helix is stabilized by which of the following interactions?

hydrogen bonds between elements of the peptide backbone

The beta sheet is stabilized by which of the following interactions?

hydrogen bonds between elements of the peptide backbone

kinesin motor proteins

hydrolyze ATP and move toward the plus end of the microtubule

Where in a motile cell would you expect to find most of ARP complex?

in the lamellapodium

In a motile cell, where would you expect to find the highest concentration of the ARP complex?

in the lamellipodium

Lysozyme is an antimicrobial enzyme found in saliva.

hydrolyzes peptidoglycan it does NOT hydrolyze proteins binds to 6 sugar residues of the substrate employs coordinated acid base catalysis binding of the substrate results in distortion of the D ring

A cluster of amphipathic transmembrane alpha helices would most likely form a(n)..

hydrophilic channel

The tertiary structure of proteins is stabilized primarily by ...

hydrophobic bonds

for double pass integral membrane proteins

if first hydrophobic AA sequence is INTERNAL then N terminus is in Cytosol

for single pass integral membrane proteins

if first hydrophobic AA sequence is at N-terminal then N terminus is in ER lumen second sequence of hydrophobic AAs act as stop transfer signal

How do mitogens stimulate mitotic activity?

inactivation of Rb

Complete the following sentence. Mitochondrial proteins encoded by the nuclear genome are transported into the mitochondrion only when they ...

include an N-terminal mitochondrial signal sequence are unfolded are bound to transport receptor on the outer mitochondrial membrane are accompanied by chaperone proteins

How do survival factors prevent apoptosis?

increased biosynthesis of the Bcl-2 protein

Which of the following is likely to decrease the fluidity of a phospholipid bilayer?

increased saturation in fatty acid tails

inhibitory synapse

influx of Cl- tends to keep membrane polarized, decreasing the likelihood of firing an action potential

excitatory synapse

influx of Na+ depolarizes membrane, increasing the likelihood of firing an action potential

Chloramphenicol

inhibit peptidyl transferase

In gram negative bacteria, ABC translocators are found principally in the ...

inner (plasma) membrane

Detergents are required to isolate integral membrane proteins because ...

integral proteins contain hydrophobic regions that associate with the fatty acid tails of membrane phospholipids

Which protein in fibroblasts plasma membrane attaches to the extracellular matrix on the outside of the cell and (through adapter molecules) to actin inside the cell?

integrin

Which of the following CAMs are components of focal adhesions and hemidesmosomes?

integrins

Which of the following cell adhesion molecules (CAMs) is NOT a component of cell-cell junctions? selectins N-CAMs integrins I-CAMs cadherins

integrins

Which of the following cell adhesion proteins (CAMs) is NOT a component of cell-cell junctions?

integrins

Which of the following statements is True regarding the immunoglobin molecules?

it is a heterotetramer composed of two light chains and two heavy chains there are two antigen binding domains The antigens binding domain(s) includes elements of both the light and heavy chains the light and heavy chains are stabilized by disulifde bonds

immunoglobulin molecule

it is a heterotetramer composed of two light chains and two heavy chains there are two antigen binding domains the antigen binding domain(s) include elements of both the light and heavy chains the light and heavy chains are stabilized by disulfide bonds

bacteriorhodopsin

it is a light-activated proton pump it has seven transmembrane alpha helixes it includes a covalently-bound retinal cofactor it pumps protons out of the cytosol

Which of the following best describes the gaseous messenger, nitric oxide

it is a paracrine messenger produced from arginine

What happens to ubiquitin after the protein to which it was attached is processed by the proteasome?

it is depolymerized and recycled

How is phosphatidylserine different from all other phospholipids?

it is negatively charged at neutral pH

What is the function of the centriole?

it is required for production of cilia

What is the function of the large intracellular loop of a G-protein coupled receptor?

it is the G-protein binding site

What process drives the formation of closed clathrin polymers from assembled triskelions?

it is thermodynamically favored

Anaphase cannot be completed unless cyclin B is inactivated. How does this occur?

it is ubiquinated

During apoptosis, how does cytochrome C get out of the mitochondrion?

it leaves through channels formed by "BH123" proteins

During apoptosis, how does cytochrome C get out of the mitochondrion?

it leaves through channels formed by BH123 proteins

What is the function of the "GTP Cap" on microtubules

it prevents catastrophic shortening of the microtubule

What is the role of p21 in cell cycle regulation?

it prevents entry into S-phase

How does cytochrome C initiate apoptosis?

it promotes the recruitment of initiator procaspases

Phospholipase Cβ activation leads to the production of (at least) two signaling molecules; inositol 1,4,5-trisphosphate (IP3) and diacylglycerol. What is the function of IP3?

it promotes the release of Ca2+ from the ER

Phospholipase C-beta activation leads to the production of two signaling molecules; inositol 1,4,5-triphosphate and diacylglycerol. What is the function on IP3

it simulates release of Ca2+ from smooth ER

How does the anti-cancer drug taxol inhibit cell division?

it stabilizes microtubules

Phospholipase C-beta activation leads to the production of at least 2 signaling molecules, IP3 and diacylglycerol. What is the function of IP3? -it recruits Akt kinase to the plasma membrane -it recruits protein kinase C to the plasma membrane -it stimulates the release of calcium from the smooth ER -it activates adenylyl cyclase

it stimulates the release of calcium from the smooth ER

Phospholipase Cbeta activation leads to the production of (at least) two signaling molecules; inositol 1,4,5-trisphosphate (IP3) and diacylglycerol. What is the function of IP3?

it stimulates the release of calcium from the smooth ER

The Green Fluorescent Protein (GFP) was isolated from which of the following organisms?

jellyfish

38) Choose the selection that best completes the following sentence. The human genome contains ... a) 3.2 billion base pairs of DNA encoding 2,300 unique genes b) 3.2 million base pairs of DNA encoding 23,000 unique genes c) 23,000 unique genes comprising 15% of total DNA d) 230,000 unique genes comprising 1.5 % of total DNA e) mostly junk DNA

junk

Which of the following intermediate filaments is the cytoskeletal component of desmosomes between epithelial cells?

keratins

Which of the following kinesin promotes catastrophic depolymerization of microtubules?

kinesin 13

What is the energy source that drives chromosomal segregation during anaphase A?

kinetochore microtubule catastrophe

What is the name of the thin sheet like structures that a fibroblast regularly extends during cell crawling

lamellipodia

Which of the following is a component of the basal lamina?

laminin

basal lamina

laminin collagen proteoglycans

F/V type pump

large complex only pumps H+ 3 ATP/cycle 4 H+ per ATP F0/F1 ATPase

Glycoproteins with terminal mannose-6-phosphate (M6P) residues are sorted to ...

late endosomes

The FRAP (Fluorescence Recovery After Photobleaching) technique would be most useful for measuring which of the following?

lateral motion of proteins within the plasma membrane

Excitatory neurotransmitters like glutamic acid depolarize postsynaptic neurons by activating which of the following proteins?

ligan gated sodium channels

What is the energy source for active transport of protons (H+) by bacteriorhodopsin?

light

Cadherin proteins In desmosomes cadherin molecules are anchored inside an epithelial cell to which type of cytoskeletal filament?

link epithelial cells together by binding to similar cadherins in adjacent cells

What is the term for the relatively thick regions of the plasma membrane into which sphingomyelin and signaling proteins are often concentrated?

lipid rafts

Removal of the of the centrioles from a eukaryotic cell would result in which of the following?

loss of cilia

Enzymes increase the rate of chemical reactions by ...

lowering the activation energy for the reaction

Which of the following cancers is most common among American men?

lung and bronchial cancer

Which of the following cancers is most common among American women?

lung and bronchial cancer

Which of the following amino acids is positively charged at neutral pH?

lysine

Growth factors increase protein synthesis and decrease protein degradation by activating which of the following?

mTOR

Growth factor signal through PI3 kinase pathway. What protein complex is activated during growth factor signaling, resulting in increase protein synthesis and decrease protein degradation? -ribosome -RNA pol -spliceosome -mTOR complex

mTOR complex

Growth factors signal through the PI3 kinase pathway. Which of the following protein complexes is activated during growth factor signaling, and both promotes protein synthesis, and inhibits protein degradation?

mTOR complex

32) Which category of molecules comprises the greatest percentage of the dry weight of a typical animal cell? a) Inorganic ions b) sugars and precursors c) nucleotides and precursors d) fatty acids and precursors e) macromolecules

macromolecules

Which category of molecules comprises the greatest percentage of the dry weight of a typical animal cell?

macromolecules

limit of spatial resolution of contrast microscopy is not a function of wavelength of light refractive index angular magnifying power

magnifying power

which of the following statemens is flase a. microtubules grow fastest from the plus end b. microtubule are composed of 13 protofilaments c. microtubules undergo catastrophe during they fray at the minus end d. microtubules are often stablized by plus of the microtubule e. all of the above are flase f. all above are true

microtubules undergo catastrophe during which they fray at the minus end

composed of actin filaments

microvilli of epithelial cells contractile ring lamellipodia stress fibers

The endomembrane system of eucaryotic cells includes all of the following organelles except ... nucleus mitochondria Golgi appartus endosome

mitochondria

The membranes of which organelle occupy the most volume in a "typical" cell.

mitochondria

what has double membrane

mitochondria nuclear envelope chloroplasts

The endosymbiosis hypothesis concerns which of the following organelles ?

mitochondria and chloroplasts

The endosymbiosis hypothesis concerns which of the following organelles?

mitochondria and chloroplasts

Endosymbiosis describes the relationship between which of the following?

mitochondria and eukaryotes

Which of the following organelles has both an outer and an inner membrane?

mitochondrion

36) Domains of proteins that are recombined through gene duplication to form proteins with new combinations of functionality are called ... a) motifs b) globules c) cassettes d) domains e) modules

modules

Domains of proteins that are recombined through gene duplication to form proteins with new combinations of functionality are called ...

modules

Functional regions of proteins that are recombined through gene duplication to form proteins with new combinations of functionality are called ...

modules

During the misfolded protein response, a transcription factor is activated that drives the expression of certain proteins. Which of the following proteins is most highly expressed during the misfolded protein response?

molecular chaperones

Choose the selection that best completes the following sentence. The human genome contains ...

mostly junk DNA

Ubiquinated plasma membrane receptor proteins are sorted to ...

multivesicular bodies

During G1 phase, which of the following prevents entry into S-phase when DNA damage is present?

p53

Transport of ER resident proteins from the Golgi complex back to the ER is "driven" by ...

pH difference between Golgi and ER lumen

During receptor mediated endocytosis, receptor complexes are ...

packaged into clathrin coated vesicles and transported to early endosomes

What happens to properly folded proteins in the ER lumen that do not display any other sorting signals?

packaged into secretory vesicles an released via the constitutive pathway

Many of the extracellular signal molecules that regulate inflammation are released locally at the site of infection. What form of cell-to-cell signaling is being used?

paracrine

Nitric oxide is an example of which of the following?

paracrine messenger

A membrane protein that can be isolated from the membrane under relatively mild conditions (e.g., pH, ionic strength, etc) is most likely a(n)

peripheral membrane protein

__________ are fairly small organelles that provide a safe place within the cell to carry out certain biochemical reactions that generate harmful, highly reactive oxygen species. These chemicals are both generated and broken down in the same location.

peroxisomes

Cells ingest large particles by

phagocytosis

Which of the following compounds binds to actin filaments and is frequently used to as an affinity reagent for fluorescent labeling of the actin cytoskeleton?

phalloidin

phosphoglycerides

phosphatidyl choline phosphatidyl serine phosphatidyl ethanolamine phosphatidyl inositol

Which of the following phospholipids is found in lowest abundance in most biomembranes?

phosphatidyl inositol

At the plasma membrane, which of the following phospholipids is found exclusively on the intracellular leaflet?

phosphatidyl serine

Which of the following phospholipid is negatively charged at neutral pH?

phosphatidyl serine

Which phospholipid is negatively charged at neutral pH?

phosphatidyl serine

lipid rafts are composed of

phosphatidylcholine sphingomyelin and cholesterol

Which of the following substrates is phosphorylated by the PI3 kinase?

phosphatidylinositol 4,5-biphosphate

Which of the following substrates is phosphorylated by the PI3 kinase?

phosphatidylinositol 4,5-bisphosphate

Which enzyme cleaves phosphatidyl inositol (4,5) bisphosphate to yield two important signaling molecules?

phospholipase C

Which of the following events prevents a second round of DNA replication

phosphorylation of ORC

Which of the following events occurs first during ion transport by the sodium-potassium ATPase?

phosphorylation of a critical aspartate residue on the transporter

During the transport cycle of the Na-K ATPase, which of the following events causes the conformation change that transports SODIUM IONS OUT of the cell?

phosphorylation of an aspartate residue

During the transport cycle of the calcium ATPase, which of the following events causes the conformation change that enables transport of 2 calcium ions out of the cytosol?

phosphorylation of an aspartate residue

Which of the following is NOT required for the activation of M-Cdk? a) binding of cyclin B b) phosphorylation of cyclin B c) phosphorylation of M-Cdk at the stimulatory site d) dephosphorylation of M-Cdk at the inhibitory site

phosphorylation of cyclin B

what is the most common phospholipid (phosphoglyceride) in biomembranes

phosphotidyl choline

Proteins that contain an SH2 (src homology 2) domain are likely to bind to which of the following features of a protein partner?

phosphotyrosine residue

Proteins that contain an SH@ domain are likely to bind to which of the following structural features of a protein partner?

phosphotyrosine residue

The src homology domain 2 (SH2 domain) binds which of the following with high affinity?

phosphotyrosine residues

All of the information required for the proper folding of proteins is contained in the ...

primary structure of the polypeptide

Apoptosis can be induced by ...

pro-caspase activation expression of Bcl-2genes suppression of Bcl-2 genes release of cytochrome c from mitochondria

Apoptosis can be induced by which of the following?

pro-caspase activation expression of some Bcl-2 genes suppression of other Bcl-2 genes release of cytochrome C from mitochondria

functions of the mitochondria

programmed cell death oxidative phosphorylation Citric acid cycle (AKA "Krebs' cycle, AKA tricarboxylic acid cycle , AKA TCA cycle)

Proteins that contain an SH3 (src homology 3) domain are likely to bind to which of the following features of a protein partner?

proline-rich domain

20) Breakdown of the nuclear envelop occurs during which phase of mitosis? a) prophase b) prometaphase c) metaphase d) anaphase e) telophase

prometaphase

Breakdown of the nuclear envelop occurs during which phase of mitosis?

prometaphase

Complete the following sentence: The anti-apoptotic protein, Bcl2, prevents apoptosis by ...

promoting the aggregation of BH4321 proteins.

Caspases are

proteases

Caspases are ...

proteases

Complete the following sentence: Caspases are ...

proteases

Occurs in Golgi complex

protein glycosylation protein sorting protein surveillance

Which of the following is false regarding transport of proteins into the mitochondrion?an N-terminal signal sequence targets proteins to the mitochondrion proteins are transported across the mitochondrial membranes in the folded state transport is powered by a proton electrochemical gradient and ATP hydrolysis the signal sequence is cleaved after transport

proteins are transported across the mitochondrial membranes in the folded state

sorting and transport of proteins to peroxisomes

proteins destined for the peroxisome display a c-terminal ser-lys-leu sorting signal proteins are transported in the folded state proteins are escorted across the membrane by peroxins

Which event happens immediately before chromosomal segregation?

proteolytic cleavage of cohesions by separase

Which event immediately precedes chromosomal segregation?

proteolytic cleavage of cohesions by separase

How are receptor tyrosine kinases activated?

receptor dimerization

Most mitogens, growth factors and survival factors signal through ...

receptor tyrosine kinases

What is the function of the Sar1-GTPase?

recruits COP2 proteins to the donor membrane

Signal mediated up-regulation of cell surface receptors involves the transfer of sequestered receptors from which of the following compartments?

recycling endosomes

Spare cell surface receptors and transport proteins are often "stored" in ...

recycling endosomes

The illusion that the path of light is bent at the interface between air and a body of water is called...

refraction

Methylation of the ε-amino group of lysine 9 on the histone H3 component of a nucleosome usually results in which of the following?

silencing of the associated gene

Which of the following statements is FALSE regarding the immunoglobulin molecule? it is a heterotetramer composed of two light chains and two heavy chains there are four antigen binding domains the antigen binding domain(s) include elements of both the light and heavy chains the light and heavy chains are stabilized by disulfide bonds

there are four antigen binding domains

Which of the following is false regarding NMDA receptors?

they are activated by glutamate they require depolarization before opening they gate calcium channels they are normally blocked by magnesium ions

What is the ultimate fate of apoptotic cells?

they are consumed by macrophages

What ultimately happens to mis-folded proteins in the ER lumen?

they are degraded in the cytoplasm

Lysosomal hydrolases capable of hydrolyzing virtually any biopolymer, are transported from the Golgi complex to late endosomes, which ultimately mature into lysosomes. Sometimes, endosomes rupture, spilling their contents into the cytosol. Fortunately, a special property of these enzymes prevents the cytosolic damage that might occur when anendosome ruptures. What is this special property?

they are inactive at cytosolic pH

During receptor mediated endocytosis, endocytic vesicles fuse with early endosomes. In some cases, the cytosolic domains of endocytosed membrane proteins are ubiquinated by cytosolic ubiquitin ligase. What is the fate of these proteins

they are incorporated into intralumenal vesicles and degraded in endolysosomes

they are packaged into secretory vesicles by recycling endosomes

During LDL-receptor mediated endocytosis, clathrin-formed vesicles containing the LDL particle-receptor complexes fuse with sorting endosomes. What happens to the LDL receptors?

they are returned to the plasma membrane

During receptor mediated endocytosis, clathrin-formed vesicles containing the ligand-receptor complexes fuse with sorting endosomes. What happens to the receptors?

they are returned to the plasma membrane

Mis-folded soluble proteins fail to leave the ER lumen in transport vesicles because ...

they can't bind to cargo receptors

Why are prions pathogenic?

they catalyze the misfiling of specific proteins

nucleosomes

they contain hetero-octomeric histone complexes they include 147 base pairs of DNA they control access to DNA

When a differentiating cell displays the Delta ligand, adjacent cells that express the Notch receptor do which of the following.

they do not become neurons

What do ESCRT protein complexes do?

they form intraluminal vesicles in endosomes

Which of the following is an important function of heat shock proteins?

they help soluble proteins fold properly

Which of the following is TRUE regarding dynein motor proteins?

they hydrolyze ATP and move toward the minus (-) end of the microtubule

dynein motor proteins

they hydrolyze ATP and move toward the minus (-) end of the microtubule

What is the function of gamma tubulin ring complexes?

they nucleate polymerization of microtubules

What do BiP proteins do?

they recognize mis-folded proteins in the ER lumen

Which of the following best describes the orientation of a protein in the ER membrane that contains three internal hydrophobic domains, but no N-terminal hydrophobic domain?

three transmembrane alpha helices with N-terminal in the cytosol

Which of the following best describes the orientation of an ER membrane protein containing three INTERNAL runs of 18 small, non-polar amino acids (i.e., no N-terminal signal sequence).

three transmembrane domains with the carboxyl terminal in the ER lumen

tight junctions

Which of the following cell junctions does NOT include a cytoskeletal component? adherens junctions desmosomes hemidesmosomes tight junctions

tight junctions

Which of the following cell-cell junctions is responsible for preventing the diffusion of solutes between apical and basolateral extracellular compartments in epithelial tissues?

tight junctions

Which of the following best describes the apical-to-basolateral order of occurrence of cell-cell junctions in an epithelial sheet?

tight junctions - adherens junctions - desmosomes - gap junctions

Which of the following best describes the apical-to-basolateral order of occurrence of cell-cell junctions in an epithelial cell?

tight junctions -adherens junctions - desmosomes - gap junctions

Secretory vesicles bud from the ...

trans-Golgi network

What is the term for the movement of vesicles formed at the apical membrane, to fuse with the basolateral membrane of epithelial cells?

transcytosis

Shortly after a ribosome translates a series of 8 or more consecutive hydrophobic amino acids, translation of the protein ceases. Translation does not begin again until ...

transfer to the ER translocation channel

During the transport cycle for the sodium-potassium ATPase, which event occurs immediately after dephosphorylation of the critical aspartate residue?

transport of 2 potassium ions from the extracellular compartment to the cytosolic compartment

What is facilitated diffusion?

transport of a solute molecule along its concentration gradient by a carrier protein

What happens at "Coated Pits"

transport vesicles form

Which of the following serves as the minus (-) end capping protein of actin filaments in striated muscle?

tropomodulin

Which of the following binds calcium ions and promotes skeletal muscle contraction?

troponin complex

Is the following statement TRUE or FALSE? "When an occupied nuclear import receptor binds RAN-GTP, the cargo protein is released."

true

Is the following statement True or False? "Only the extracellular domains of membrane glycoproteins are glycosylated."

true

Signaling via a GPCR (G protein coupled receptor) ceases when the alpha subunit of an activated G protein hydrolyzes its bound GTP to GDP.

true

Which of the following best describes the orientation of a protein in the ER membrane that contains N-terminal ER localization signal and two internal hydrophobic domains?

two transmembrane alpha helices with N-terminal in the ER lumen

Complete the following sentence. "Most enzyme-coupled receptors signal through ..."

tyrosine kinases

At the anaphase checkpoint, which of the following events must occur for mitosis to proceed?

ubiquination of cyclin B

Which of the following is NOT required for the full activation of M-Cdk?

ubiquination of cyclin B

Anaphase promoting complex (APC) is a(n)

ubiquitin ligase

E3 ligase attaches

ubiquitin to epsilon amino group of a lysine residue on target membrane

Tertiary structure is stabilized by which of the following?

van der Waals attractions between hydrophobic amino acid side chains

Tertiary structure of proteins is primarily stabilized by which of the following non-covalent bonds?

van-der-Waals attraction between hydrophobic amino acid side chains

Neurotransmitter release from the presynaptic terminal requires the activation of which of the following ion channels?

voltage gated calcium channels

Neurotransmitter release from the presynaptic terminal requires the activation of which of the following ion channels?

voltage grated calcium channels

diffraction is a characteristic of

wave dynamics

In light microscopy, the limit of spatial resolution is determined by

wavelength of light refractive index of the medium angular aperture of the objective

Which of the following is a substrate for M-Cdk complex

wee1 cdc25 lamin B

During dynamic instability of microtubules, when does the "catastrophic" shortening of microtubules occur?

when the microtubule loses its GTP cap

When does "catastrophe" occur?

when the microtubules lose its GTP cap

When is a misfolded protein considered to be a "prion"?

when the protein transmits disease to other organisms

when does tradmilling of actin filaments occurs

when the rate of actin polymerixation at plus end is equal to the rate of actin depolymerization at minus end

Which of the following is the inhibitory binding partner for transcriptions factor E2F?

Rb protein

The Medelson & Stahl experiment demonstrated that DNA replication occurs through which of the following mechanisms?

semiconservative

What is the function of n-ethylmaleimide sensitive factor (NSF)?

separation of SNARE complexes

In a Lineweaver-Burk plot of the dependence of enzyme velocity on substrate concentration, what is the value of the function at Y=0 (i.e., the X-intercept)?

-1/Km

In a Lineweaver-Burk plot of the dependence of enzyme velocity on substrate concentration, what is the value of the function at Y=0?

-1/km

Which of the following amino acid sequence marks a protein for retention in the ER lumen

... -Lys-Asp-Glu-Leu-COOH

Which of the following amino sequence does NOT mark the asparagine residue for N-glycosylation?

...N-A-P...

the marking of proteins with ubiquitin

1. activation of ubiquitin by E1 2. transfer of ubiquitin to E2 3. target protein displaying degradation sequence binds to substrate site on E3 4. E3 ligase attaches ubiquitin to epsilon amino group of a lysine residue on target protein

ubiquitylation of proteins

3 enzyme complex mediates the ubiquitylation of proteins ubiquitin is attached to the e amino acid of a lysine side chain on the target protein long chains of ubiquitin increase the probability of degradation of a target protein by the 20s proteasome

Proteins with one or more amphipathic alpha helices are uniquely capable of forming which of the following structural features?

A coiled coil

Which of the following proteins assists in activating a typical G-protein?

A guanine nucleotide exchange factor

What best describes the orientation within the ER membrane of a protein with an N-terminal ER sorting sequence, and 3 internal runs of 8 or more non-polar AAs?

A protein with 3 transmembrane alpha helices and the C-terminus in the cytosol

The effect of pertussis toxin treatment on trimeric G-protein signaling is due to which covalent modification? -ubiquination of the alpha subunit -ADP ribosylation of the alpha subunit -phosphorylation of the alpha subunit -phosphorylation of the beta-gamma complex -dephosphorylation of the beta-gamma complex

ADP ribosylation of the alpha subunit

In a motile cell, where would you expect to find most of the ARP complex? A. at the leading edge of the cell B. at the trailing edge of the cell C. bound to the endoplasmic reticulum D. in the cortex of the cell E. in none of the above

A. at the leading edge of the cell

Which of the following is NOT a structure comprised mostly of actin filaments? A. primary cilium B. lamellipodium C. contractile ring D. microvilli E. stress fiber

A. primary cilium

which is the largest family of membrane transport proteins

ABC (ATP Binding Cassete) Pumps

How is the asymmetrical distribution of phospholipids across the plasma membrane created?

ABC transporter move them between the cytosolic and luminal leaflets of the ER membrane

How is the asymmetrical distribution of phospholipids across the plasma membrane created?

ABC transporters move them between the cytosolic and luminal leaflets of the ER membrane

The Cystic Fibrosis Transmembrane Regulator is a member of which of the following transporter families?

ABC-type pump

The effect of cholera toxin treatment on trimeric G-protein signaling is due to which of the following covalent modifications?

ADP ribosylation of the alpha subunit

48) Which of the following is false regarding gap junctions? a) they are formed by proteins called connexins b) six protein subunits form a single connexon hemichannel c) connexon hemichannels on adjacent cells associate to form the functional gap junction d) calcium ions and small metabolites can pass through gap junctions e) all of the above are true regarding gap junctions

ALL TRUE

You have isolated a temperature sensitive yeast mutant. When maintained at the restrictive temperature , all of the yeast cells are arrested at the Metaphase-Anaphase checkpoint due to a loss-of-function mutation of a signal gene. Which of the following proteins complexes is most likely responsible for the observed phenotype?

APC/C

internal signal sequences direct proteins to the nuclear compartment

APPRRRKRV

Which of the following protein complexes is responsible for the nucleation of actin polymerization at the leading edge of motile cells?

ARP complexes

During movement of myosin motor proteins along filament, which of the following events results in release of the motor head from the actin filament?

ATP binding

Which of the follow results in the release of the actin filament by the myosin motor head?

ATP binding

During the movement of kinesin dimer along a microtubule, which of the following events is responsible for the "power stroke"

ATP exchange for bound ADP on the leading head

HSP70-type molecular chaperones

ATP exchange results in the dissociation of chaperone proteins from hydrophobic amino acids on the target protein.

Which is FALSE of N-glycosylation process? -N-glycosylation begins in ER lumen -A preformed, 14 residue oligosaccharide is transferred to the amide nitrogen of an asparagine residue or on glycoprotein -the 1st 7 sugar residues of oligosaccharide are attached to the dolichol carrier on cytosolic side of ER membrane -last 3 glucose residues of oligosaccharide must be removed prior to incorporation of the glycoprotein into COP2 vesicles

All are true

Many anti-cancer drugs target microtubule cytoskeleton. What describes this class of anti-cancer drugs? -drugs that destabilize microtubules -drugs that stabilize microtubules -drugs that prevent microtubule polymerization -drugs that promote microtubule polymerization

All of the above

During signaling through a G-proteins coupled receptor, GTP exchange on the alpha subunit of a trimeric G-protein complex is facilitated by binding to which of the following?

An occupied receptor

GTP exchange on the alpha subunit of a trimeric G-protein is facilitated by binding what? -A receptor -an occupied receptor -an effector protein -beta-gamma complex

An occupied receptor

) In the lab, you have cultured cells that express a trimeric G protein of the Gs family. Which of the following best describes the expected result of cholera toxin treatment on these cells? a) cAMP levels go down b) cAMP levels go up c) cGMP levels go up d) IP3 levels go down e) IP3 levels go up

Which of the following is phosphorylated by S-Cdk to initiate DNA synthesis during S-phase? A. MPF B. cdc6 C. Helicase D. DNA polymerase E. ORC

B. cdc6

What is the function of the centriole? A. it is required for the production of microtubules B. it is required for production of cilia C. it is required for the production of the spindle complex D. it is required chromosomal segregation E. it has no known function

B. it is required for production of cilia

39) Which of the following initiates microtubule polymerization? a) formins b) gamma tubulin ring complexes c) centrioles d) cdc42 e) none of the above

b) gamma tubulin ring complexes

During signaling though a trimeric G-protein, how is the action of the beta-gamma complex terminated?

Binding to the GDP-bound form of the alpha subunit

During signaling through a trimeric G-protein, how is the action of the beta-gamma complex terminated? -GTP hydrolysis -ATP hydrolysis -binding to GDP-bound form of alpha subunit -binding to GTP-bound form of alpha subunit -binding to effector protein

Binding to the GDP-bound form of the alpha subunit

What are T-tubules?

extensions of the plasma membrane

How does cytochrome C escape mitochondria to promote apoptosis?

By leaving through channels in the outer membrane formed by BH123 proteins

How might the Golgi complex monitor the 'progress" of the post translation protein processing?

By modification of the N-oligosaccharide

How might the Golgi complex monitor the progress of post-translation protein processing -by a program of N-terminal proteolysis -by a pattern of lysine ubiquination -by modifications of N-oligosaccharide -by changes in protein conformation

By modifications of N-oligosaccharide

How does the anti-apoptotic protein, Bcl2, prevent apoptosis?

By preventing the aggression of "BH123" proteins

How does cytochrome C promote apoptosis via the intrinsic pathway

By promoting the aggregation of initiator procaspases

During embryonic development, how does the Notch receptor signal that is has bound a Delta ligand? -by activated a tyrosine kinase -by increasing cyclic AMP -by increasing cyclic GMP -by activating PI3 kinase -by releasing a proteolytic fragment of the receptor into the cytosol

By releasing a proteolytic fragment of the receptor into the cytosol

Prior to vesicle formation, how are adaptins recruited to the appropriate membrane -by the amount of phosphatidylserine on the membrane -by specific phosphoionsitides on the cytosolic surface -by the pH of the compartment -by the assembly of cargo receptors

By specific phosphoionsitides on the cytosolic surface

) As a vesicle approaches the target membrane, tethering proteins bind to which of the following? a) v-SNAREs b) t-SNAREs c) Rab-GTP proteins on the vesicle d) Rab-GDP proteins on the vesicle e) Rab-GDP proteins on the target membrane

Which of the following species was chosen as a model organism for the study of invertebrate development?

Caenorhabditis elegans

Which of the following proteins serves as that plus (+) end capping proteins of actin filaments in the sarcomere?

Cap Z

Which of the following sarcomere proteins is found at the Z disc?

CapZ

Which of the following serves as the plus (+) end capping protein of actin filaments in sarcomeres?

CapZ

5 Essential Characteristics of All Living Cells

Capable of protein synthesis Capable of autonomous replication bounded by a lipid rich pm Capable of regulated metabolic activity Contains nucleic acid that encodes at least one complete copy of a genome

What provides the force that drive chromosomal segregation during anaphase A?

Catastrophic fraying of kinetochore microtubules

Which of the following is phosphorylated by S-Cdk to initiate DNA synthesis

Cdc6

What is the largest family of cell signaling proteins encoded in humans? -enzyme coupled receptors -receptor tyrosine kinases -trimeric G-proteins -small GTPases -G-protein coupled receptors

G protein coupled receptors

During the unfolded protein response, which of the following "misfolded protein sensors" in the ER membrane signals through a cytosolic ribonuclease domain by excising an intron from a pre-existing mRNA molecule?

IRE1

Which of the following diseases is NOT classified as an Amyloidosis? Transmittable Spongiform Encephalopathies (e.g., "Mad Cow") Alzheimer's Disease Huntington's Disease Chronic myelogenous leukemia

Chronic myelogenous leukemia

Most transport vesicles destined for the endosomal systems are formed by which of the following coat proteins?

Clathrin

Which is the function of the synaptic protein, synaptobrevin

IT is the V-SNARE on the synaptic vesicle

When the cyclic AMP-dependent protein kinase (PKA) enters the nucleus, it phosphorylates what transcription factor? -CREB protein -CBP -CPK -CPK2

Cyclic AMP response element binding (CREB) protein

Failure of anaphase promoting complex (APC) to ubiquinate this protein would result in arrest of cell cycle at anaphase which of the following is this proteins?

Cyclin B

11) Which of the following letters represents an amino acid that is uncharged at neutral pH? a) E b) D c) K d) L e) R

During nuclear import, what happens immediately after the binding of Ran-GTP to the nuclear import receptor? -binding of a cargo protein to the NIR -dissociation of a cargo protein from the NIR -transport of the NIR-RAN-GTP complex out of nucleus -hydrolysis of RAN-GTP to RAN-GDP

Dissociation of a cargo protein from the NIR

During movement of myosin protein along actin filament, which of the following events results in "power stroke"?

Dissociation on Pi

The ability of vesicles to fuse with target membrane is maintained at expense of ATP hydrolysis. ATP hydrolysis occurs when? -During binding of tethering proteins -during dissociation of Rab proteins -during formation of SNARE complexes -during dissociation of SNARE complexes

During dissociation of SNARE complexes

The ability of vesicles to fuse with the target membrane is maintained at the expense of ATP hydrolysis. When does ATP hydrolysis occur?

During dissociation of SNARE proteins

Which GTPase is responsible for the release of clathrin-coated vesicles from the plasma membrane? -Ran -Rab -Ras -Rac -Dynamin

Dynamin

Which of the following monomeric GTPases provides the energy for release of newly formed vesicles from the source memebrane?

Dynamin

The KDEL sequence (-Lys-Asp-Glu-Leu-COOH) tags proteins for retention in which intracellular compartment?

ER lumen

During receptor-mediated endocytosis, clathrin coated vesicles sort directly to which compartment? -cis-Golgi network -trans-Golgi network -early endosomes -late endosomes -lysosomes

Early endosomes

During receptor-mediated endocytosis, clathrin-coated vesicles sort directly to which of the following compartments?

Early endosomes

Which of the following best describes a structural feature through which a misfolded soluble proteins might be recognized by proteins surveillance machinery of the cell?

Exposed non-polar amino side chains in the cytosol

Which of the following bests describes the orientation of an ER membrane protein containing an N-terminal ER import signal sequence and four additional runs of 18 small non-polar amino acids?

Four transmembrane domains with the amino and carboxyl terminals on the same side of the membrane

Which of the following amino acid sequence could identify a secretory protein

H2N-Met-Met-Leu-Val-Ile-Ile-Gly-Ala-Val-Leu

In early anaphase, APC is activated by cdc20. During G1, when cdc20 is depleted, APC activity is maintained by which of the following proteins?

Hct1

During protein synthesis, secondary structural elements fold first. These are primarily stabilized by which of the following non-covalent bonds?

Hydrogen bonds between elements of the peptide backbone

During endosomal maturation, the luminal concentration of which ion gradually increases, with highest concentration in lysosomes? -Sodium -Potassium -Calcium -Hydrogen

Hydrogen ions

During endosomal maturation, the luminal concentration of which of the following ions gradually increase, with the highest concentration occurring in lysosomes?

Hydrogen ions

The signal recognition particle (SRP) binds to the ER sorting signal on the nascent polypeptide and stops translation. When does translation resume?

Immediately after binding of the sorting sequence to the ER translocator

The signal recognition particle binds to the ER sorting signal of the nascent polypeptide and arrests translation. When does translation resume?

Immediately after binding of the sorting sequence to the ER translocator

Protein component of the ESCRT system are responsible for the formation of which of the following vesicles

Intraluminal vesicles

Protein components of ESCRT system are responsible for the formation of which vesicles? -secretory vesicles -transport vesicles -intraluminal vesicles -synaptic vesicles -vesicular-tubular clusters (VTCs)

Intraluminal vesicles

Which of the following signal sequences identifies a protein for retention in the endoplasmic reticulum?

Lys-Asp-Glu-Leu-CO2H

During processing in the Golgi complex, which of the following proteins becomes labeled with a mannose-6-phosphate tag?

Lysosomal acid hydrolases

Which of the following phosphorylates and inactivates the Wee1 kinase at the onset of M-phase?

M-Cdk complex

Which of the following is phosphorylated by MAP kinase kinase kinase (Raf)? -MAP -MAP kinase -MAP kinase kinase -MAP phosphatase -MAP phosphatase kinase

MAP kinase kinase

The Ras GTPase participates in which of the following signaling pathways?

MAP kinase pathway

MPF refers to the substance present in the cytosol of Xenopus oocytes that is capable of driving multiple cycle of M phase and and S phase in vitro. what is MPF?

Maturation Promoting Factor

MPF refers to the substance(s) present in the cytosol of unfertilized Xenopus oocytes that is capable of driving multiple cycles of M phase and S phase in vitro. What is MPF?

Maturation Promoting Factor

Which of the following ion channel is responsible for sound detection in the cochlea?

Mechanically-gated sodium channels

import into mitochondria

Met Leu Ser Leu Arg Gln Ser Ile Arg Phe Phe Lys Pro Ala Thr Arg Thr Leu Cys Ser Ser Arg Tyr Leu Leu MLSLRQSIRFFKPATRTLCSSRYLL

Which is FALSE of microtubules? -they grow fastest from + end -they are composed of 13 protofilamnets -they undergo catastrophe where protofilaments fray at - end -they are often stabilized by + end capping proteins

Microtubules undergo catastrophe where protofilaments fray at minus end

Which of the following transport monovalent cations AGAINST their concentration gradients ?

Sodium-potassium ATPase

Intramolecular disulfide bonds between non-adjacent cysteine residues are common in integral membrane proteins to stabilize the conformation of ...

extracellular domains

What goes on in the Golgi complex?

N and O type glycosylation is completed proteolytic activity proteins are packaged into appropriate vesicles

Which of the following is NOT a function of mitochondria? programmed cell death oxidative phosphorylation N-glycosylation Citric acid cycle (AKA "Krebs' cycle, AKA tricarboxylic acid cycle , AKA TCA cycle)

N-glycosylation

Which of the following is True regarding the N-glycosylation process?

N-glycosylation begins in the ER A preformed 14 residue oligosaccharide is transferred to the amide nitrogen of an asparagine on the glycoprotein the first 7 sugar residues of the oligosaccharide are attached to the dolichol carrier o the cytoplasmic side of the ER membrane The last three residues must be moved prior to incorporation of the glycoprotein into COP@ vesicles

C-terminal sequences identify proteins for return from the cis-Golgi

NYLSCKDEL

Which of the following are arranged in order of increasing permeability (i.e., lowest to highest) to a phospholipid bilayer?

Na+ < ethanol < H2O < O2

Disintegration of the nuclear lamina and the nuclear envelope occurs during which phase of mitosis?

Prometaphase

sodium-potassium ATPase

P-class ATP-powered pump inhibited by ouabain electrogenic pumps 3 Na+ out and 2 K+ in for each ATP hydrolyzed

The ATP-dependent pump that maintains the low cytoplasmic concentration of calcium in skeletal muscle is a(n)

P-class pump

Which of the following transporter proteins undergoes covalent modification during the transport cycle?

P-type pump

Which of the following ATP-driven pumps can be made to run "backwards" and synthesize ATP?

P-type pump F/V-type pump ABC-type pump

During G1 phase, which of the following prevents entry into S-phase when DNA damage is present?

P53

Which of the following enzymes is NOT activated through G-protein coupled receptor signaling?

PI3 kinase

Which sorting signal marks soluble protein for transport to the nucleus? -PPKKKKRKL -KDEL0CO2H -H2N-MLAIVLAIV -SKL-Co2H

PPKKKRKL

Proteins with a Pleckstrin Homology domain can be recruited to the plasma by binding to a phosphorylated form of which of the following phospholipids

Phosphatidyl inositol

The AKT kinase is recruited to the plasma membrane by which of the following membrane associated molecules?

Phosphatidyl inositol 3,4,5 triphosphate

Which substrate is phosphorylated by PI3 kinase? -phosphatidylinositol 4,5-bisphosphate -phosphatidylinositol 3,4-bisphosphate -phosphatidylinositol 3,5-bisphosphate -phosphatidylinositol 3,4,5-trisphosphate

Phosphatidylionsitol 4,5 bisphosphate

During clathrin-coated vesicle formation, adaptin protein 2 (AP2) complexes are activated by specific... -Phosphoinositides -Glycolipids -Sphingolipids -Rab proteins -SNARE proteins

Phosphoinositides

During the transport cycle of the calcium ATPase, which of the following events causes the conformation change that enables transports of 2 calcium ions of the cytosol?

Phosphorylation of the an aspartate residue

Import into nucleus

Pro-Pro-Lys-Lys-Lys-Arg-Lys-Val PPKKKRKV

Which of the following monomeric GTPases directs a vesicle to the appropriate target membrane

Rab

Which of the following proteins directs vesicles to the proper target membrane?

Rab proteins

As a vesicle approaches the target membrane, tethering proteins bind what? -v-SNAREs -t-SNAREs -Rab-GTP proteins on vesicle -Rab-GDP proteins on vesicle -RAb-GDP proteins on target membrane

Rab-GTP proteins on the vesicle

When vesicles are delivered to the target membrane, they are recognized and captured by "tethering proteins" on the target membrane. To which of the following vesicular proteins do tethering proteins bind?

Rabs

Which protein family is responsible for directing transport vesicles to their target membranes?

Rabs

Which small GTPase is often activated during remodeling of the actin cytoskeleton?

Rac

Which small GTPase might be activated during remodeling of the actin cytoskeleton?

Rac

Which small GTPase might be activated during remodeling of the actin cytoskeleton?

Rac and Rho

As a vesicle approaches the target membrane, tethering proteins bind to which of the following?

Ran-GTP proteins on the vesicle

Which of the following small GTPases plays a key role in the mitogen activated protein (MAP) kinase pathway?

Ras

In the MAP kinase pathway, the small GTPase, Ras, is activated by recruitment of which of the following proteins?

Ras-GEF

Mitogens promote entry into cell cycle by inactivating which of the following proteins?

import into peroxisomes

Ser Lys Leu SKL

What is/are Caveolae?

Small endocytic vesicles containing membrane proteins and sphingomyelin

What are caveolae?

Small endocytic vesicles rich in membrane proteins and sphingomyelin

In the mitochondrion, which transport system is responsible for importation of proteins into the mitochondrial matrix?

TIM23

Growth factor signals through the AKT kinase, resulting in the phosphorylation and activation of which of the following

TOR

Is the following statement TRUE or FALSE? Glycosylated residues of integral membrane proteins are always confined to extracellular domains. a. The above statement is TRUE b. The above statement is FALSE

TRUE

The activation of M-Cdk requires

The binding of M cyclin The phosphorylation of the Cdk The dephosphorylation of the Cdk

Which of the following occur immediately after a nuclear export receptor bind to RAN-GTP?

The cargo proteins bind with high affinity

In many globular proteins, amino acids with hydrophobic side chains are gathered together during the folding process to form ...

non-polar core

In phospholipid synthesis, what do "scramblases" do?

non-specifically transfer phospholipids to the lumenal leaflet of the ER membrane

What is a glycocalyx?

The thick layer of glycosylation on the extracellular leaflet of the plasma membrane of certain cells

main function of intermediate filaments

To enable cells to withstand the mechanical stress that occurs when cells are stretched

Ultimately, the destination for vesicles containing mature proteins is determined in which of the following comperments?

Trans Golgi network

Within the Golgi complex, where can mannose 6 phosphate M6P receptors be found? -cis Golgi network -Cis Golgi cisterna -median-golgi cisterna -trans golgi cisterna -trans golgi network

Trans-Golgi network

Within the Golgi complex, where would you expect to find mannose-6-phosphate receptor?

Trans-Golgi network

resting nerve terminal

VGCC closed

activated nerve terminal

VGCC open

Which of the following kinases is responsible for phosphorylation and inactivation of M-Cdk?

Wee1

Which of the following proteins is responsible for phosphorylation and inactivation of M-cdk?

Wee1

Which of the following enzymes is responsible for the reversible inhibition of M-Cdk?

Wee1 kinase

Which of the following kinases is responsible for phosphorylation and inactivation of M-Cdk?

Wee1 kinase

During dynamic instability of microtubules, when does the catastrophic shortening of microtubules occur? -when GTP levels are exhausted -when the microtubule loses its GTP cap -when ATP levels are exhausted -when the ATP bound form of G actin falls below the critical concentration -when microtubules contact the plasma membrane

When the microtubule loses its GTP cap

When is a misfolded protein considered to be a "prion"

When the protein transmits disease to other organisms

Which of the following animals was chosen as a model species for the investigation of vertebrate development?

Xenopus Laevis

) At the metaphase-anaphase transition, which of the following proteins is ubiquinated by APC? a) cyclin B b) cdc20 c) separase d) cohesins e) none of the above are ubiquinated by APC

) Complete the following sentence: Caspases are ... a) proteases b) phosphatases c) ubiquitin ligases d) scaffold proteins e) kinases

Potassium leak channels are 10,000 fold more permeable to potassium ions. What is the structural basis for the ion selectivity of potassium leak channels?

a series of carbonyl oxygen atoms along the selectivity

Voltage-gated sodium channels are composed of

a single polypeptide with four homologous domains, each containing six transmembrane alpha helices

The Get3 ATPase facilitate post-translational insertion of certain proteins into the ER membrane. Which of following is the common feature of proteins that rely on the Get3 ATPase for insertion into the ER membrane?

a single transmembrane domain at the C-terminus

Which of the following bests describes the orientation of an ER membrane protein containing a single run of 18 small non polar amino acids located in the middle of the protein (i.e., NOT at the N-terminus)

a single transmembrane domain with the N-terminal domain in the cytosol

Which of the following bests describes the orientation of an ER membrane protein containing an N-TERMINAL ER signal sequence AND one internal run of 18 small non polar amino acids located in the middle of the protein?

a single transmembrane domain with the N-terminal in the ER lumen

Inside a muscle fiber what triggers sarcomeres to contract?

a sudden rise in intracellular calcium

Which of the following amino acid sequences identifies a protein for import into the nucleus?a) -Pro-Pro-Lys-Lys-Lys-Arg-Lys-Val- b) -Ser-Lys-Leu- c) -Lys-Asp-Glu-Leu-COOH d) -Met-Met-Leu-Leu-Leu-Val-Gly-Ile-Leu-Phe-Trp-Ala-Thr-Glu-

a) -Pro-Pro-Lys-Lys-Lys-Arg-Lys-Val-

26) Which of the following amino acid sequences is MOST LIKELY to form an coiled-coil dimer? a) ... L-A-S-T-A-N-M-L-R-E-Q-V-A-Q-L ... b) ... L-S-T-A-N-L-A-M-Q-E-R-Q-V-A-L ... c) ... L-Q-A-V-Q-E-R-L-M-N-A-T-S-A-L ... d) ... L-R-L-A-M-V-N-Q-E-A-A-Q-T-S-L ... e) ... L-A-T-S-L-A-M-N-V-A-Q-Q-E-R-L ...

a) ... L-A-S-T-A-N-M-L-R-E-Q-V-A-Q-L ...

18) Which of the following protein complexes can grow new actin filaments at a 70 degree angle from an existing actin filament? a) ARP complexes b) formin dimers c) G1S-cdk complexes d) gamma tubulin ring complexes e) none of the above

a) ARP complexes page 6

23) Some "survival signals" prevent apoptosis by phosphorylation of the BAD protein, resulting in the release of the anti-apoptotic protein, Bcl2. Which of the following kinases phosphorylates the BAD protein? a) Akt kinase b) protein kinase A c) protein kinase B d) MAP kinase e) none of the above

a) Akt kinase

16) PKA often activates gene expression by phosphorylating which of the following proteins? a) CREB protein b) CREB binding protein (CBP) c) STAT d) MAP kinase e) none of the above

a) CREB protein

22) Which of the following is the largest group of cell signaling proteins in eucaryotes? a) G protein coupled receptors b) G proteins c) receptor tyrosine kinases d) nuclear receptors e) ion channels

a) G protein coupled receptors

26) In early anaphase, APC is activated by cdc20. During G1, when cdc20 is depleted, APC activity is maintained by which of the following proteins? a) Hct1 b) G1-Cdk c) p53 d) Rb e) p21

a) Hct1

The organization of the actin cytoskeleton is primarily controlled by which of the following?

actin binding proteins

At the leading edge of the motile cell. which of the following events provides the force that drives the lamellipodium forward?

actin polymerization

Which process provides the force that propels the leading edge of a motile cell forward?

actin polymerization

Which of the following proteins is most concentrated at the leading edge of a motile cell?

actin related proteins

During vesicle formation at the plasma membrane, clathrin triskelions bind to which of the following proteins?

adaptins

Which of the following cell-cell junctions is formed by cell adhesion molecules that are associated with actin filaments?

adherens junctions

Why do action potentials propagate along the axon?

after depolarization, voltage-gated sodium channels inactivate

The BH123 proteins Bax & Bak promote apoptosis by ...

aggregating to form channels in the mitochondrial outer membrane

What did the 19th century chemist William Perkin invent?

aniline dyes

44) Which of the following is false regarding collagens? a) they are the most abundant proteins in the animal kingdom b) they are formed from three alpha helical proteins bound in a coiled-coil c) subunits are encoded by at least 20 genes d) they are assembled into fibers in the extracellular space e) all of the above are true regarding collagen

all true

Which G protein components have GTPase activity?

alpha subunit

Which of the following integrin dimers is a component of hemidesmosomes?

alpha6beta4

The Coiled Coil is a common protein dimerization domain. Which of the following structural features must be present on both proteins in order to form of a Coiled Coil?

an amphipathic alpha helix

Which of the following best describes a drug that binds to a receptor and blocks the action of a natural messenger.

an antagonist

What is a "molten globule"?

an intermediate protein conformation that occurs during protein folding

As many as 95% of people suffering from Chronic Myelogenous Leukemia carry the Philadelphia Chromosome. What is the Philadelphia Chromosome?

an unusually small chromosome the product of translocation between human chromosomes 9 and 22 a chromosome encoding an unregulated, chimeric protein kinase

N-type glycosylation involves the attachment of a pre-formed, 14 residue carbohydrate to which of the following?

asparagine residue in the luminal domain (inside the ER)

HSP70 chaperone proteins

assist in the proper folding of proteins bind nascent polypeptide in cytoplasm require ATP hydrolysis to dissociate from the nascent polypeptide

During cytokinesis, the orientation of the contractile ring is primarily determined by the location of the ...

asters

activation of ubiquitin requires

atp hydrolysis

Which of the following kinases is responsible for preventing the assembly of Ndc80 complexes on kinetochore microtubules?

aurora-B kinases

Which mechanism is used for degrading obsolete parts of a cell, such as a defective mitochondria?

autophagy

) What is the function of the "GTP Cap" on microtubules a) it is a binding site for kinesin motors b) it prevents catastrophic shortening of the microtubule c) it prevents the hydrolysis of GTP by the alpha subunit d)it prevents the hydrolysis of GTP by the beta subunit e) no consequence

) Which of the following kinase-cyclin pairs is correctly matched? a) S Cdk & cyclin B b) G1-S Cdk & cyclin E c) M Cdk & cyclin C d) G1-Cdk & cyclin A e) All are correctly matched

. An extracellular messenger molecule that increases intracellular calcium levels in target cells, and is NOT blocked by pertussis toxin, probably signals through which of the following trimeric G-proteins? a) Go d) Gi b) Gq e) Gt c) Gs

. Proteins expressing a C-terminal KDEL sequence are returned to the ER in which of the following? a) clathrin-coated vesicles b) COP1 vesicles c) COP2 vesicles d) in caveoli e) diffusion through the cytosol

12) What is the function of the "GTP Cap" on microtubules a) it is a binding site for kinesin motors b) it prevents catastrophic shortening of the microtubule c) it prevents the hydrolysis of GTP by the alpha subunit d) it prevents the hydrolysis of GTP by the beta subunit e) it is of no consequence

13) During kinesin movement along a microtubule, what happens immediately after nucleotide exchange? a) the motor head releases the microtubule b) the neck linker "zippers" onto the leading head c) the trailing head dissociates d) the leading head binds tightly e) the leading head is thrust forward

15) Which of the following is TRUE regarding most kinesin motor proteins? a) they hydrolyze ATP and move toward the minus (-) end of the microtubule b) they hydrolyze ATP and move toward the plus (+) end of the microtubule c) they hydrolyze ATP and move toward the plus (+) end of the actin filament d) they hydrolyze GTP and move toward the plus (+) end of the microtubule e) they hydrolyze GTP and move toward the minus (-) end of the microtubule

16) Which small GTPase is often activated during remodeling of the actin cytoskeleton? a) Rap d) Ran b) Rac e) Ras c) Rab

54) Which of the following enzymes is responsible for the reversible inhibition of M-Cdk? a) cdc25 phosphatase b) Wee1 kinase c) S-Cdk d) CAK kinase e) none of the above

b) Wee1 kinase although it is wee... it has a lot of power to INHIBIT dat entry to m phase thooo

8) Which of the following proteins releases calcium from the sarcoplasmic reticulum in response to muscle depolarization? a) the nicotinic cholinergic receptor b) a calcium -gated calcium channel c) a voltage-gated calcium channel d) an M-type calcium ATPase e) a sodium-calcium antiporter

b) a calcium -gated calcium channel

47) Which of the following kinases is responsible for preventing the assembly of Ndc80 complexes on kinetochore microtubules? a) M-Cdk complex b) aurora-B kinase c) cyclin activating kinase (CAK) d) polo kinase e) MAP kinase

b) aurora-B kinase page 5 cell cycle 2

44) What is the role of the tropomyosin in striated muscle contraction? a) activates myosin light chain kinase b) blocks myosin binding sites on actin filaments c) transmits action potentials to myofibrils d) opens calcium channels on the sarcoplasmic reticulum e) it binds calcium

b) blocks myosin binding sites on actin filaments

37) How does p53 activation prevent entry into S-Phase? a) by promoting the expression of cyclin E b) by phosphorylating S-cdk c) by promoting the synthesis of Cdk inhibitors d) by inhibiting APC e) by inhibiting the production of G1S-cdk components

b) by phosphorylating S-cdk

34) How does the anti-apoptotic protein, Bcl2, prevent apoptosis? a) by preventing the aggregation of "BH3 only" proteins b) by preventing the aggregation of "BH123" proteins c) by promoting the aggregation of "BH123" proteins d) by phosphorylating the BAD protein e) by returning cytochrome C to the mitochondrion

b) by preventing the aggregation of "BH123" proteins page 7 apoptosis

8) Which of the following coat proteins is/are responsible for the formation of endocytic vesicles at the plasma membrane? a) COP proteins b) clathrin c) dynamin d) Rab GTPases e) vSNAREs

b) clathrin

22) Which of the following refers to the proteins that are cleaved by separase to release sister chromatids at anaphase? a) separins b) cohesins c) condensins d) anaphase promoting complex (APC) e) cyclin B

b) cohesins page 16 cell cycle 1

56) The protein complexes that gather and organize DNA strands into chromosomes are called ... a) compactins b) condensins c) gatherins d) cohesins e) none of the abov

b) condensins the chromosomes are now dense

16) The incorporation of a small aperture ("pinhole") near the detector that limits the transmission of out-of-focus light emitted from the specimen is an important feature of which of the following optical techniques? a) laser scanning microscopy b) confocal microscopy c) differential interference contrast microscopy d) phase contrast microscopy e) none of the above

b) confocal microscopy

15) In rapidly dividing cells, MPF activity was observed to oscillate, with peak levels occurring at the G2 - M transition). The oscillatory component of the MPF complex was later shown to be which of the following proteins? a) cyclin A b) cyclin B c) cyclin C d) cyclin dependent kinase 1 (Cdk1) e) cyclin dependent kinase 2 (Cdk2)

b) cyclin B

53) In Xenopus (frog) oocytes, MPF activity was observed to oscillate, with peak levels occurring at the G2 - M transition. The oscillatory component of the MPF complex was later shown to be which of the following proteins? a) cyclin A b) cyclin B c) cyclin C d) cyclin dependent kinase 1 (Cdk1) e) cyclin dependent kinase 2 (Cdk2)

b) cyclin B cyclin b is the cyclin in M-cdk. this is the cdk that triggers from g2 to m phase

6) A loss of function mutation of the p53 gene would result in ... a) increased p21 expression leading to arrest of the cell cycle at G1 b) decreased p21 expression leading to unregulated entry into S phase c) decreased probability of replication of damaged DNA d) increased biosynthesis of genes controlling S phase events e. decreased biosynthesis of genes controlling G1 phase events

b) decreased p21 expression leading to unregulated entry into S phase

10) Which of the following microscopic techniques provides the highest resolution images of unstained, living cells? a) confocal laser scanning microscopy b) differential interference contrast microscopy c) fluorescence microscopy d) scanning electron microscopy e) transmission electron microscopy

b) differential interference contrast microscopy

12) What event in the SNARE cycle requires the hydrolysis of ATP? a) binding of v-SNAREs to t-SNAREs b) dissociation of SNARE complexes c) binding of Rab GTPases to the SNARE complex d) dissociation of Rab GTPases from the SNARE complex e) binding of Rab GTPases to the tethering proteins complex

b) dissociation of SNARE complexes it takes energy to loosen them up

28) Vinculin, together with Talin dimers, couple integrin dimers to the actin cytoskeleton in which of the following cell matrix junctions ? a) hemidesmosomes b) focal adhesions c) tight junctions d) adherens junctions e) gap junctions

b) focal adhesions page 12 extracellular matrix

9) During receptor mediated endocytosis, which event recruits adaptins to the plasma membrane? a) phosphorylation of membrane proteins b) formation of receptor-ligand complexes c) changes in phospholipid asymmetry d) GTP hydrolysis by the dynamin complex e) binding of clathrin

b) formation of receptor-ligand complexes

Which of the following organelles is responsible for the synthesis of new membrane for components of the endomembrane system?

endoplasmic reticulum

Which organelle sorts ingested molecules and recycles some of them back to the PM?

endosome

Clathrin-coated vesicles usually transport their contents to which of the following?

endosomes

Most clathrin-coated vesicles are destined for which of the following cell compartments?

endosomes

Which of the following terms best describes a chemical reaction in which the Enthalpy change (delta-H) is a positive value?

endothermic

During kinesin movement along a microtubule, which event causes the neck linker to "zipper onto the head domain" (i.e., the "Power Stroke")

exchange of ADP for ATP

Glycolipids are found ...

exclusively on the extracellular leaflet of the plasma membrane

phosphatidylserine is found

exclusively on the inner leaflet

Which of the following is one way in which a misfolded protein might be recognized by the protein surveillance machinery of the cell?

exposed non-polar amino acid side chains

33) Which of the following amino acids is uncharged at neutral pH? a) glutamate b) aspartate c) glutamine d) arginine e) lysine

glutamine

Which of the following amino acids is uncharged at neutral pH?

glutamine

Which of the following phospholipids is found exclusively on the extracellular leaflet of the plasma membrane?

glycolipids

The ER signal sequence on a growing polypeptide chain is recognized by a signal recognition particle (SRP) in the cytosol. This interaction

guides the ribosomes and its polypeptide to the ER membrane

Which of the following enzymes is responsible for unwinding the DNA double helix during DNA replication?

helicase

Which process insures the fusion of vesicles with the proper target membrane?

high affinity binding of complementary SNARE complexes

Which of the following histones uniquely promotes the formation of the 30 nm chromatin fiber?

histone H1

microtubules are

hollow tubes

cell adhesion molecules (CAMs) of cell-cell junctions

selectins N-CAMs I-CAMs cadherins

Transport of ions across cell membranes occurs most rapidly through ...

ion channels

Which of the following is false regarding N-glycosylation? a. it begins in the Golgi complex b. a branched 14 sugar oligosaccharide is assembled on the lipid carrier, dolichol c. the oligosaccharide is transferred to an asparagine residue on the protein d. many secretory proteins are modified by N-glycosylation

it begins in the Golgi complex

Lysozyme is an antibacterial enzyme found in saliva. Which of the following statement about lysozyme is true?

it binds to 6 sugar residue of the substrate it employs coordinated acid base catalysis Binding of the substrate results in distortion of the "D" rings

What is the role of Hct1 in the cell cycle?

it binds to APC to promote G1

What is the role of the tropomyosin in striated muscle contraction?

it blocks myosin binding sites on actin filaments

What is the role of tropomyosin in striated muscle contraction?

it blocks myosin binding sites on actin filaments

The initiator tRNA is different from all other tRNAs in what way?

it can bind directly to the P-site on the small subunit

How does the DNA mismatch repair system recognize and repair only the newly synthesized strand?

it contains nicks left over from lagging strand synthesis

How does BOTOX work?

it degrades SNARE proteins

What is the role of the cyclin component of a cyclin-dependent protein kinase complex?

it determines the substrate specificity of the kinase

The patch clamp technique is important because ...

it enables the study of ion channel properties

Which of the following is/are true regarding the NMDA receptor?

it is a glutamate-gate calcium channel in the resting state, the channel is blocked by a single magnesium ion it is involved thought to be involved in the molecular mechanism underlying learning and memory in the brain sustained activation often results in an increase in the density of glutamate receptors on the postsynaptic membrane

In the trans-Golgi network, pro-enzyme hydrolases destined for late endosomes are identified by which of the following features?

mannose-6-phosphate moiety on the oligosaccharide

MPF refers to the substance(s) present in the cytosol of unfertilized Xenopus oocytes that is capable of driving multiple cycles of M phase and S phase in vitro. What is MPF?

maturation promoting factor

The substance in the cytoplasm of M-phase cells that promotes mitosis in cell-free extracts of Xenopus oocytes was originally called ...

maturation promoting factor

In the auditory system, "hair cells" are depolarized during activation of which of the following ion

mechanically-gated cation channels

The closing of the Venus flytrap is triggered by which of the following ion channel types?

mechanically-gated ion channels

What is the most important consequence of pinocytosis?

membrane turnover

What is the term for a receptor that indirectly activates an ion channel on the plasma membrane.

metabotropic

Which of the following best describes a signaling system in which activation of a G-protein coupled receptor results in increased potassium conductance through the action of the beta-gamma complex?

metabotropic

Which of the following statements is TRUE regarding microtubules?

microtubules are composed of 13 "protofilaments" microtubules display the property of dynamic instability microtubules undergo "catastrophe", during which they fray at the plus (+) end

microtubules

microtubules are composed of 13 protofilaments microtubules undergo catastrophe, during which they fray at the plus end microtubules are often stabilized by plus end capping proteins

Which of the following statements is FALSE regarding microtubules? a) microtubules grow fastest from the minus (-) end b) microtubules are composed of 13 "protofilaments" c) microtubules undergo "catastrophe", during which they fray at the plus (+) end d) microtubules are often stabilized by plus end capping proteins e) all of the above are TRUE regarding microtubules

microtubules grow fastest from the minus (-) end

Myelinated axons conduct action potentials much faster than unmyelinated axons because ...

myelin is an excellent insulator voltage gated ion channels are concentrated at the nodes action potential re-generation occurs only at the nodes

Constriction of the contractile ring during cytokinesis is driven by

myosin II

During cytokinesis, which of the following motor proteins closes the contractile ring?

myosin II

Which of the following motor proteins is responsible for the constriction of the contractile ring during cytokinesis?

myosin II and actin

When a cell is acutely injured, it usually dies by

necrosis

two waves out of phase

negative interference (dim)

Which of the following is NOT composed of actin filaments?

neuronal axon

Which of the following best describes the microtubular structure of the axoneme of spermatozoa?

nine sets of doublet microtubules surrounding two singlet microtubules

The active site of most enzymes is primarily composed of which of the following?

non-adjacent polar amino acids

The actives site of most enzymes is primarily composed of which of the following?

non-adjacent, polar/Charged amino acids

part of the endomembrane system

nuclear envelope ER Golgi complex plasma membrane

components of the endomembrane system

nuclear envelope ER gogli apparatus endoscopes lysosomes transport vesicles PM

Which of the following is phosphorylated by the M-Cdk complex?

nuclear lamin B

Which of the following types of intermediate filaments are found in all animal cells?

nuclear lamina

Which of the following intermediate filaments is found in all animal cells?

nuclear lamins

Cortisol, testosterone and thyroxine signal through which of the following proteins?

nuclear receptors

Stem cell division produces which of the following?

one stem cell and one precursor cell

Which of the following events is responsible for the depolarization phase of the action potential?

opening of volt gated sodium channels

During the action potential, which event results in re-polarization of the axonal membrane?

opening of voltage gated potassium channels

Most procaspases are activated by ...

other caspases

Which of the following events occurs immediately after GTP hydrolysis by elongation factor Tu (EF-Tu).

release of the aminoacyl t-RNA

Phosphorylation of the Rb protein by G1-Cdk promotes the G1-S phase transition by ...

releasing transcription factor E2F resulting in biosynthesis of S phase proteins

Complete the following sentence. During the processing of plasma membrane proteins, "A domain that is cytosolic at the ER level ..."

remains cytosolic at the plasma membrane

Which of the following best describes the general mechanism of DNA replication?

semi-conservative template directed polymerization

phospholipid flippases

responsible for the establishment of phospholipid asymmetry in the plasma membrane

The directionality of protein transport across the nuclear pore complex is due to which of the following?

restriction of RAN GEF to the nuclear department

Directional transport through nuclear pore complexes is due, in part, to which of the following?

restriction of RAN-GEF to the nuclear compartment

What is the smallest contractile unit in striated muscle cells?

sarcomere

What is the term for the smallest contractile unit of skeletal muscle

sarcomere

What is the source of the calcium that permits contraction of skeletal muscle?

sarcoplasmic reticulum

Which of the following microscopic techniques provides the highest resolution images of the surface morphology of a specimen?

scanning electron microscopy

Which mode of representation of the tertiary structure of a protein provides the most information about the location and orientation of secondary structural elements?

schematic / ribbon model

Which mode of representation of the tertiary structure of a protein provides the most information about the location and orientation of secondary structural elements?

schematic/ribbon model

Secretory protein processing is completed in the ...

secretory vesicle

At The metaphase-anaphase checkpoint, anaphase promoting complex ubiquinated which of the following proteins to release separase from inhibition

securin

Which of the following is NOT a phosphoglyceride?

sphingomyelin

which of the following phospholipids is NOT a phosphoglycerol?

sphingomyelin

How is sphingomyelin different from membrane phospholipids like phosphatidylcholine?

sphingomyelin is not a phosphoglyceride

Which of the following is a microtubules organizing center

spindle pole basal body centrosome spindle pole

During the formation of clathrin coated vesicles, what happens immediately after vesicle release?

spontaneous dissociation of coat proteins

The changes in ion permeability of the axonal membrane that give rise to the action potential were first determined using which model organism?

squid

Which of the following polysaccharides is a biopolymer of glucose sugars in "alpha 1 -> 4" linkage?

starch

Which of the following is an actin rich structure

stress fibers the lamellipodium microvilli

The internal signal sequence, PPKKKKRV, identifies a protein for transport to which of the following compartments?

the nucleus

During endosomal maturation, there is a gradual decline in which of the following characteristics?

the pH of the endosome

Which of the following is FALSE regarding transport of proteins into the mitochondria. the proteins must display an N-terminal mitochondrial signal sequence (NTMSS) the protein must be delivered in the unfolded state the protein binds via its NTMSS to a receptor component of the TOM complex after TOM and TIM align, the protein passes across both membranes into the matric the process is powered entirely by the pH gradient across the inner membrane

the process is powered entirely by the pH gradient across the inner membrane

protein degradation in the 20S proteasome

the process requires ATP hydolysis only proteins tagged with ubiquitin can gain access to the proteasome this process plays an important role in many cell regulatory processes

In the Cross-Bridge Ratchet model of mitochondrial protein transport ...

the protein is pulled into the matrix by chaperone proteins

transport of proteins into the mitochondria.

the proteins must display an N-terminal mitochondrial signal sequence (NTMSS) the protein must be delivered in the unfolded state the protein binds via its NTMSS to a receptor component of the TOM complex after TOM and TIM align, the protein passes across both membranes into the matrix

In general, the nature of the cellular response to a chemical messenger is determined primarily by which of the following

the receptive apparatus of the cell

What is (are) the hypothetical function(s) of ABC translocator proteins in eucaryotic cells?

the removal of toxic materials from the cell

Transport of proteins through the nuclear pore complex is powered by the Ran-GTP/Ran-GDP gradient across the nuclear envelope. What factor gives rise to this gradient?

the restriction of Ran GEF and Ran GAP to opposite sides of the nuclear envelope

The resting membrane potential of neurons is primarily determined by which of the following?

the selective permeability of plasma membrane to potassium ions

Chronic Myelogenous Leukemia (CML) is usually caused by a translocation event that produces the Philadelphia Chromosome. Which consequence of this translocation is responsible CML?

the translocation produces an unregulated chimeric protein kinase on chromosome 22

The spatial resolution of optical microscopy is primarily a function of which of the following?

CBE3

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