Cell Bio - Exam 2

Question

Post-translational translocation of non-secretory proteins across membranes could occur in which organelles?

Answer 1

mitochondria

Answer 2

chloroplasts

Answer 3

peroxisomes

Answer 4

ER signal sequence is translated at free ribosome

Answer 5

Sequence allows ribosome to bind to a translocator on RER

Answer 6

Pore is formed and polypeptide is translated through to the RER lumen

Answer 7

Signal peptidase cleaves signal sequence

Answer 8

Protein is released into the ER lumen

Answer 9

Secretory proteins translated in vitro were smaller than those in vivo. Microsomes from ER added to in vitro proteins resulted in larger size.

Answer 10

Secretory proteins were the same size in vitro and in vivo.

Answer 11

Secretory proteins translated in vitro were larger than those in vivo. Microsomes from ER added to in vitro proteins resulted in correct size.

Answer 12

vary greatly but have 6+ hydrophobic aa string at N terminus

Answer 13

vary greatly but have 8+ hydrophobic aa string at N terminus

Answer 14

vary greatly but have 6+ hydrophobic aa string at C terminus

Answer 15

vary greatly but have 8+ hydrophobic aa string at C terminus

Answer 16

Hydrophilic pocket lined with methionine, which has inflexible side chains.

Answer 17

Hydrophobic pocket lined with methionine, which has flexible side chains.

Answer 18

Hydrophobic pocket lined with methionine, which has inflexible side chains.

Answer 19

SRP binds to small ribosomal subunit

Answer 20

SRP binds to large ribosomal subunit.

Answer 21

Binding pocket fits around nascent chain exit site and binds to ER signal sequence.

Answer 22

Translational pause domain positions at interface between ribosomal subunits.

Answer 23

SRP binds to SRP-R.

Answer 24

Mechanism possibly related to GDP binding sites near SRP-R.

Answer 25

SRP released, translation continues embedded in ER.

Answer 26

ER signal sequence binds to hydrophobic site on inside of locator, opening the channel.

Answer 27

Polypeptide extruded into ER, peptidase cleaves signal.

Answer 28

One time. SRP.

Answer 29

Two times. SRP, SRP-R.

Answer 30

Three times. SRP, SRP-R, signal peptidase.

Answer 31

Integration of TMDs.

Answer 32

Cleaved signal sequence to diffuse into membrane.

Answer 33

Ribosome to insert peptide from side.

Answer 34

Hydrophobic influence in Sec 61 pore.

Answer 35

N terminus in ER lumen.

Answer 36

C terminus in ER lumen.

Answer 37

N terminus in ER lumen.

Answer 38

C terminus in ER lumen.

Answer 39

Location of (+) charge, always goes to cytosol

Answer 40

Location of (+) charge, always goes to ER lumen

Answer 41

Location of 3 aa repeat, always goes to cytosol

Answer 42

Location of 3 aa repeat, always goes to ER lumen

Answer 43

There is an internal start-transfer sequence and C-terminus stop-transfer sequence.

Answer 44

There is an N-terminus start-transfer sequence and a C-terminus stop-transfer sequence.

Answer 45

There is an internal start-transfer sequence and internal stop-transfer sequence.

Answer 46

There is an N-terminus start-transfer sequence and an internal stop-transfer sequence.

Answer 47

They have an ER retention signal.

Answer 48

They are too small to be absorbed into vesicles.

Answer 49

They are anchored on a special receptor called ER-R.

Answer 50

Protein disulfide isomerase.

Answer 51

Protein disulfur isomerase.

Answer 52

Protein disulfide isomerate.

Answer 53

Protein disulfur isomerate.

Answer 54

Formation of disulfide bonds between sulfhydryls of cysteins.

Answer 55

Formation of disulfide bonds between sulfhydryls of nucleotides.

Answer 56

Binding to unfolded proteins to prevent aggregation.

Answer 57

Binding to unfolded proteins to facilitate aggregation.

Answer 58

Binding Protein.

Answer 59

Binder Protein.

Answer 60

Binding in Protein.

Answer 61

Binding to unfolded proteins and preventing aggregation.

Answer 62

Binding to unfolded proteins and promoting aggregation.

Answer 63

Forming disulfide bonds between sulfhydryls of cysteins.

Answer 64

Forming disulfide bonds between sulfhydryls of nucleotides.

Answer 65

Secretory pathway in the Golgi.

Answer 66

Secretory pathway in the ER.

Answer 67

Proper folding of proteins.

Answer 68

Aggregation of proteins.

Answer 69

Folding proteins.

Answer 70

Protecting against degradation.

Answer 71

Cell communication.

Answer 72

N-linked glycosylation.

Answer 73

O-linked glycosylation.

Answer 74

Amide nitrogen of asparagine.

Answer 75

Amide nitrogen of cysteine.

Answer 76

Amide nitrogen of serine.

Answer 77

oligosaccharyl transferase.

Answer 78

oligosaccglycol transferase.

Answer 79

oligoseryl transferase.

Answer 80

14 sugar compound of GlcNAc, mannose, glucose.

Answer 81

14 sugar compound of GlcNAc, mannose.

Answer 82

16 sugar compound of GlcNAc, mannose, glucose.

Answer 83

16 sugar compound of GlcNAc, mannose.

Answer 84

All asparagines.

Answer 85

Only asparagines within a specific sequence (Asn - X - Ser/Thr).

Answer 86

2 GlcNAc, 3 Man

Answer 87

3 GlcNAc, 2 Man

Answer 88

2 Glu, 3 GlcNAc

Answer 89

3 Glu, 2 GlcNAc

Answer 90

2 Man, 3 Glu

Answer 91

3 Man, 2 Glu

Answer 92

Holds sugar structure awaiting transfer by OST.

Answer 93

Builds sugar structure awaiting transfer by OST.

Answer 94

Facilitates ATP hydrolysis of OST.

Answer 95

Holds energy for sugar transfer in pyrophosphate bond.

Answer 96

Uses ATP to transfer sugar.

Answer 97

Uses GTP to transfer sugar.

Answer 98

Is associated with every Sec 61 translocator and each has a dolichol anchor nearby.

Answer 99

Is associated with some Sec 61 translocators and each has a dolichol anchor nearby.

Answer 100

Is associated with all Sec 61 translocators but not dolichols.

Answer 101

During translation of the target protein.

Answer 102

After the signal peptide is cleaved.

Answer 103

The instant translation finishes.

Answer 104

8 Man, 2 GlcNAc

Answer 105

6 Man, 2 GlcNAc

Answer 106

2 Man, 8 GlcNAc

Answer 107

2 Man, 6 GlcNAc

Answer 108

Makes up about 90% of glycosylation events.

Answer 109

Makes up about 10% of glycosylation events.

Answer 110

Involves attachment of sugar to hydroxyl group of serine.

Answer 111

Involves attachment of sugar to hydroxyl group of threonine.

Answer 112

In membrane layer.

Answer 113

Cytosolic face.

Answer 114

ER lumen face.

Answer 115

Is very hydrophobic, spans bilayer 3+ times.

Answer 116

Is very hydrophilic, spans bilayer 3+ times.

Answer 117

Is very hydrophobic, spans bilayer 2 times.

Answer 118

Is very hydrophilic, spans bilayer 2 times.

Answer 119

Is en bloc.

Answer 120

Is one sugar at a time.

Answer 121

In the membrane.

Answer 122

Within dolichol.

Answer 123

Between dolichol and the sugar group.

Answer 124

In the sugar group.

Answer 125

On the end of the sugar group.

Answer 126

Prevent unproperly folded proteins from leaving the ER.

Answer 127

Keep ER resident proteins critical for proper folding inside the ER.

Answer 128

Are the only proteins needed for proper management of proteins in the ER.

Answer 129

Calnexin recognizes a single glucose after glucose trimming.

Answer 130

Calnexin recognizes a double glucose after glucose trimming.

Answer 131

ER resident glucosidase removes final glucose(s) off of protein.

Answer 132

Calreticulin recognizes absence of glucose and binds.

Answer 133

If proper folding occurs, protein is bound by glucosyl transferase.

Answer 134

Inproperly folded proteins have sugars added back onto their N-linked oligo to go back through cycle.

Answer 135

Protein goes through retrotranslocation.

Answer 136

Protein possibly goes back through Sec61.

Answer 137

N-glycanase removes oligosaccharide chains en bloc in ER.

Answer 138

Oligosaccharide chains removed in cytosol.

Answer 139

Ubiquitin marks proteins for degradation by recognizing certain sequences that should not be exposed in properly-folded proteins.

Answer 140

Lysosome breaks down ubiquitin-marked proteins.

Answer 141

Proteaomse processes ubiquitin-marked proteins.

Answer 142

They are processed in the same manner as proteins that are incorrectly folded once recognized.

Answer 143

They have an organic timer mediated by mannosidase.

Answer 144

Calnexin cycle resets the mannose timer.

Answer 145

Proteins that fold properly keep all their mannoses.

Answer 146

Accumulation of unfolded proteins in ER.

Answer 147

Activation by high proteasome activity.

Answer 148

Increased transcription of genes involving ER chaperones, retrotranslocation proteins, protein-folding proteins.

Answer 149

Involve IRE1.

Answer 150

is a transmembrane protein kinase.

Answer 151

is an ER chaperone catalyst.

Answer 152

autophosphorylates.

Answer 153

dimerizes.

Answer 154

trimerizes.

Answer 155

has endoribonuclease domain that edits a specific mRNA in cytosol.

Answer 156

affects activation of genes in nucleus through mRNA editing.

Answer 157

enters the nucleus after signaling to affect gene transcription.

Answer 158

GTP binding protein.

Answer 159

ATP binding protein.

Answer 160

guanine nucleotide exchange factor.

Answer 161

guanine export factor.

Answer 162

is an ER membrane protein.

Answer 163

is a cytosolic protein.

Answer 164

is a type of GEF.

Answer 165

binds Sar1-GDP and catalyzes release of GDP and binding of GTP.

Answer 166

binds Sar1-GTP and catalyzes hydrolysation and subsequent release of GDP.

Answer 167

is involved with COPI vesicles.

Answer 168

is involved with COPII vesicles.

Answer 169

Sar1-GTP serves as a binding site for Sec23 & 24.

Answer 170

Sec23 & 24 select cargo.

Answer 171

Sec13 & 31 proteins form second layer to COPII structure.

Answer 172

Sec16 increases coat polymerization efficacy.

Answer 173

Sec17 increases coat polymerization efficacy.

Answer 174

Sec23 promotes GTP hydrolysis of Sar1-ATP.

Answer 175

Sec23 promotes GTP hydrolysis of Sar1-GTP.

Answer 176

Sar1-GDP is released from vesicle membrane, allowing coat to rapidly dissemble.

Answer 177

t-SNARE is exposed on surface, allowing fusing process to begin.

Answer 178

v-SNARE is exposed on surface, allowing fusing process to begin.

Answer 179

Vesicle binding is mediated by Rab GTPase.

Answer 180

Cytosolic Rab-GDP converted to Rab-GTP by GEF.

Answer 181

Rab-GTP binds to Rab effector on target membrane.

Answer 182

t-SNARE and v-SNARE become close enough to interact and "hook."

Answer 183

NSF with an alpha-SNAP binds the SNAREs.

Answer 184

NSF catalyzes hydrolysis of ATP, forming energy needed to dissociate SNARE complexes.

Answer 185

Rab protein hydrolyzes its bound GTP releasing Rab effector.

Answer 186

Rab-GDP is released into cytosol for next cycle.

Answer 187

Some vesicles detached from the ER directly fused with the Golgi if the travel distance was short.

Answer 188

COPII vesicles traveled toward the Golgi when originally thought COPII did retrograde transport back to the ER.

Answer 189

If Golgi was several micrometers away, vesicles en route to Golgi fused prior to Golgi contact, forming cis-Golgi network.

Answer 190

Retrograde vesicles budded off the Golgi toward the ER.

Answer 191

trans-Golgi network formed after trans-Golgi pushed out of Golgi from cisternal maturation.

Answer 192

Return t-SNARE.

Answer 193

Return v-SNARE.

Answer 194

Return membrane to ER.

Answer 195

Retrieve ER resident proteins.

Answer 196

Bring proteins back for new modifications before packaging to PM.

Answer 197

6 large cytosolic polypeptide complexes (coatomers).

Answer 198

4 large cytosolic polypeptide complexes (coatomers).

Answer 199

Coatomers with alpha and beta subunits.

Answer 200

Whole coatomers, no subunits.

Answer 201

Sec12, a GEF.

Answer 202

ARF (ADP ribosylation factor).

Answer 203

Sar1, a GTP-binding factor.

Answer 204

ARF-GDP is weakly tethered to the Golgi membrane by a weak covalent protein mod on N-terminus.

Answer 205

ARF-GTP is strongly tethered to the Golgi membrane by a strong covalent protein mod on N-terminus.

Answer 206

GEF on Golgi catalyzes formation of ARF-GTP. ARF now strongly tethered to Golgi membrane.

Answer 207

Tight association of ARF-GTP serves as foundation for coatomer formation on COPI vesicles.

Answer 208

Coat dissembles and Rab mediates binding to target membrane.

Answer 209

SNARES facilitate fusion to target membrane.

Answer 210

Mutant COPI vesicles lacked the ability to perform vesicle transport of proteins to the Golgi apparatus.

Answer 211

Mutant COPI vesicles successfully formed vesicles, but the mutation made them immediately fuse back with the ER so transport did not occur.

Answer 212

Mutant COPI vesicles could not bring back proteins necessary for anterograde transport to continue.

Answer 213

Mutant COPI vesicles fused readily with COPII vesicles, interrupting the transport chain.

Answer 214

They easily get trapped in outgoing vesicles.

Answer 215

Retrograde transport is necessary to maintain presence of ER resident proteins in the ER.

Answer 216

Specialized receptors prevent ER resident proteins from getting entrapped in outgoing vesicles.

Answer 217

ER resident proteins are mostly free in the ER lumen, so outgoing vesicles usually do not trap ER resident proteins, and the cell can replace readily those that do.

Answer 218

By an ER retention signal (KDEL) that passes directly to the membrane, causing a COPI vesicle to form.

Answer 219

By an ER retention signal (KDEL) that binds to a special KDEL Receptor in low pHs, allowing retrograde transport.

Answer 220

By an ER retention signal (KDEL) that binds to a special KDEL Receptor in high pHs, allowing retrograde transport.

Answer 221

By an ER retention signal (KDEL) that binds to KDEL Receptor on COPII vesicles, essentially redirecting the vesicle to the ER before fusion with the Golgi.

Answer 222

KKXX signal on C terminus.

Answer 223

KKXX signal on N terminus.

Answer 224

KDEL signal on C terminus.

Answer 225

KDEL signal on N terminus.

Answer 226

3 Man, 2 Glu on C terminus.

Answer 227

3 Man, 2 Glu on N terminus.

Answer 228

Take back ER resident proteins.

Answer 229

Forward modified proteins to the next part of the Golgi.

Answer 230

outer phospholipids of COPI vesicles.

Answer 231

alpha and beta subunits of COPI vesicles.

Answer 232

special KDEL-R receptor on COPI vesicles.

Answer 233

still have successful retrograde transport of KDEL-signal proteins.

Answer 234

have proteins that need to be transported back to the ER remaining in the Golgi.

Answer 235

send KDEL-marked proteins to lysosomes.

Answer 236

lack the problem of having ER-resident proteins being erroneously sent to the Golgi.

Answer 237

had cell-wall glycoproteins assembled in the Golgi that were 20X larger than any observed vesicle.

Answer 238

had cell-wall glycoproteins that were small enough to fit inside vesicles.

Answer 239

had cell-wall glycoproteins that were about as large as vesicles, spurring additional research into cisternal maturation.

Answer 240

involves precollagen, a precusor too large for vesicles.

Answer 241

involves precollagen aggregates, which have never been seen in vesicles.

Answer 242

provides evidence for cisternal maturation.

Answer 243

provides evidence for anterograde vesicular transport in the Golgi.

Answer 244

provides evidence that retrograde Golgi transport of enzymes occurs.

Answer 245

involves trimming of precollagen, the pieces of which are transported backwards via vesicles in the Golgi.

Answer 246

involves COPII vesicles to bring enzymes in the Golgi forward as cisternal maturation occurs.

Answer 247

COPI vesicles.

Answer 248

COPII vesicles.

Answer 249

They don't. They move back in the same compartment via cisternal maturation.

Answer 250

en bloc modifications to the oligosaccharides, where a protein's modification is processed separately and one exchange occurs before exportation.

Answer 251

sequential modifications to the oligosaccharides, where each product is another enzyme's substrate.

Answer 252

varies different proteins' oligosaccharides.

Answer 253

uniforms different proteins' oligosaccharides.

Answer 254

Lysosomal proteins come to the Golgi with (Man)8(GlcNAc)2 oligosaccharide.

Answer 255

Lysosomal proteins come to the Golgi with (Man)3(GlcNAc)2 oligosaccharide.

Answer 256

2 cis Golgi residents form the M6P.

Answer 257

2 medial Golgi residents form the M6P.

Answer 258

M6P is an oligosaccharide.

Answer 259

N-acetylglucosamine phosphotransferase binds to lysosomal protein signal.

Answer 260

N-acetylglucosamine phosphotransferase catalyzes addition of phosphorylated GlcNAc group to carbon 6 of mannose on enzyme oligosaccharide.

Answer 261

GlcNAc phosphotransferase can mistakenly add M6P to secretory proteins.

Answer 262

Phosphodiesterase removes GlcNAc, leaving a phosphate.

Answer 263

Phosphodiesterase removes phosphate, leaving the oligosaccharide.

Answer 264

PM via constitutive secretion.

Answer 265

PM via selective secretion.

Answer 266

PM via regulated secretion.

Answer 267

Lysosome via late endosome.

Answer 268

Lysosome directly.

Answer 269

PM directly.

Answer 270

ER via retrograde transport.

Answer 271

ER directly.

Answer 272

involves release of a protein after a stimulus.

Answer 273

involves constant and direct secretion of a protein.

Answer 274

involves storing a protein in a vesicle for long term storage.

Answer 275

involves sending a protein directly to the PM.

Answer 276

involves nothing.

Answer 277

Proteins in vesicles from t-Golgi network aggregate before fusing with the target storage vesicle.

Answer 278

Proteins in vesicles fuse directly to the target storage vesicle without aggregation.

Answer 279

Chromogranin.

Answer 280

Chromogranin A.

Answer 281

Chromogranin B.

Answer 282

Chromogranin I.

Answer 283

Chromogranin II.

Answer 284

aggregate only in storage vesicles.

Answer 285

aggregate in the t-Golgi network, but only with a pH of 6.5 and 1mM Ca2+.

Answer 286

aggregate in the t-Golgi network, but only with a pH of 5.5 and 1mM Ca2+.

Answer 287

may be basis for sorting secretory proteins either into regulated or constitutive secretion.

Answer 288

is not involved in sorting secretory proteins into regulated or constitutive secretion.

Answer 289

will not be secreted.

Answer 290

will only be secreted from a storage vesicle.

Answer 291

will be carried to the PM for constitutive secretion.

Answer 292

Chromogranin aggregations do not bind with secretory proteins.

Answer 293

undergo proteolytic cleavage to form a mature, active protein.

Answer 294

undergo proteolytic cleavage in the t-Golgi network.

Answer 295

in mammalian cells are probably processed by furin.

Answer 296

in mammalian cells are probably processed by endoprotease PC2.

Answer 297

are cleaved once, at C-terminal dibasic sequence.

Answer 298

are cleaved once, at N-terminal dibasic sequence.

Answer 299

are exoproteases.

Answer 300

act on proproteins for constitutive secreted proteins.

Answer 301

can help form insulin from proinsulin.

Answer 302

is cleaved to form N-terminal B chain and C-terminal A chain connected by disulfide bonds.

Answer 303

is a constitutive secreted protein.

Answer 304

probably has processing done by carboxypeptidase, which removes 2 basic aa residues.

Answer 305

keeps harmful enzymes from acting anywhere except its target organelle.

Answer 306

Peptides that are too large need to be contained in proproteins.

Answer 307

ex. enkephalins would not be synthesizable without proteolytic processing.

Answer 308

long alpha helices that coil to form a four alpha helix bundle.

Answer 309

long alpha helices that coil to form a two alpha helix bundle.

Answer 310

Hydrophobic residues at central core.

Answer 311

Hydrophilic residues at central core.

Answer 312

Alignment of aas of opposite charge forming favorable electrostatic interaction.

Answer 313

mediates COPI and COPII vesicles.

Answer 314

mediates lysosomal enzyme transport vesicles.

Answer 315

are diskelions.

Answer 316

have three limbs.

Answer 317

polymerize to form polygonal lattice.

Answer 318

associates with AP complexes when monomer.

Answer 319

associates with AP complexes when polymerized.

Answer 320

AP1, helps with t-Golgi network to endosome transport.

Answer 321

AP1, helps with PM to endosome transport.

Answer 322

AP2, helps with PM to endosome transport.

Answer 323

AP2, helps with endosome to t-Golgi network transport.

Answer 324

AP3, helps with t-Golgi network to lysosome transport.

Answer 325

AP3, helps with t-Golgi network to endosome transport.

Answer 326

a new type of AP.

Answer 327

a clathrin GTPase.

Answer 328

can help deliver proteins to melanosomes in skin cells.

Answer 329

can help mediate protein transport to specialized compartments.

Answer 330

may not need clathrin for its vesicles to function.

Answer 331

helps vesicles bypass the late endosome.

Answer 332

hydrolyzes ATP.

Answer 333

hydrolyzes GTP.

Answer 334

helps COPI and COPII vesicles form.

Answer 335

works via conformational change that pinches vesicles.

Answer 336

is a constitutive expressed molecular chaperone.

Answer 337

does not exist.

Answer 338

uses ATP hydrolysis.

Answer 339

uses GTP hydrolysis.

Answer 340

allows v-SNARE exposure and binding via Rab effector action.

Answer 341

allows t-SNARE exposure.

Answer 342

M6P receptor binds in TGN.

Answer 343

pH must be 5.5 for M6P receptor to function.

Answer 344

ARF allows for coat assembly.

Answer 345

M6P receptor has YXXF.

Answer 346

M6P receptor has YXXo.

Answer 347

Dynamin does its thang.

Answer 348

Vesicle is uncoated via Hsc70.

Answer 349

Rab-GTP binds with Rab effector to facilitate SNARE interactions.

Answer 350

M6P receptor dissociates at lysosomal pH, and a phosphatase breaks up M6P.

Answer 351

Some M6P is then transferred to cell surface.

Answer 352

because it is sent there from the ER.

Answer 353

to release lysosomal enzymes into the ECM.

Answer 354

to retrieve lysosomal enzymes that were missorted.

Answer 355

25% of own volume per hour.

Answer 356

5% of PM per minute.

Answer 357

is actin-mediated.

Answer 358

involves pseudopodia that surround target particle.

Answer 359

requires substances to transmit signals to inside of the cell.

Answer 360

is used by almost all cell types.

Answer 361

recognize and bind infection organisms.

Answer 362

aid in pseudopodia development.

Answer 363

bind to other cells to mark as friendly.

Answer 364

involves clathrin-coated pits.

Answer 365

mostly utilizes AP1.

Answer 366

mostly utilizes AP2.

Answer 367

mostly utilizes AP3.

Answer 368

requires GTP hydrolysis to occur.

Answer 369

requires that receptors be recycled.

Answer 370

involves receptors that are freshly made from the Golgi.

Answer 371

number of receptors.

Answer 372

GTP concentration.

Answer 373

ATP concentration.

Answer 374

clathrin abundancy.

Answer 375

cholesterol carriers

Answer 376

erroneously sorted lysosomal proteins

Answer 377

protein hormones

Answer 378

transferrin

Answer 379

iron-binding proteins

Answer 380

maintain membrane fluidity.

Answer 381

fatty acid conversion.

Answer 382

synthesis of steroids.

Answer 383

killing heart tissue.

Answer 384

lipoproteins.

Answer 385

lipocholesterols.

Answer 386

lipocarriers.

Answer 387

McDonald's.

Answer 388

high levels of protein.

Answer 389

high levels of lipids.

Answer 390

high levels of cholesterol.

Answer 391

cholesterol.

Answer 392

apolipoproteins.

Answer 393

polioproteins.

Answer 394

cholesterol-containing phospholipid monolayer.

Answer 395

cholesterol-containing phospholipid bilayer.

Answer 396

cholesterol-containing phospholipid trilayer.

Answer 397

outer hydrophilic surface.

Answer 398

inner hydrophilic surface.

Answer 399

outer hydrophobic surface.

Answer 400

inner hydrophobic surface.

Answer 401

is the major cholesterol carrier.

Answer 402

carries more cholesterol than HDL.

Answer 403

has hydrophobic core with about 1500 esterified chol. molecules.

Answer 404

has only one apolipoprotein called apoA-100.

Answer 405

has one TMD.

Answer 406

has two TMDs.

Answer 407

has long terminal N exoplasmic segment with ligand binding arm.

Answer 408

has long terminal C exoplasmic segment with ligand binding arm.

Answer 409

has binding arm with 7 cysteine-rich repeats of 40aa each.

Answer 410

has binding arm with 5 cysteine-rich repeats of 30aa each.

Answer 411

has YXXP signal.

Answer 412

has NPXY signal.

Answer 413

binds to AP-1.

Answer 414

binds to AP-2.

Answer 415

Neutral pH of cell surface allows apoB binding to LDL-R binding arm.

Answer 416

NPXY signal grabs AP-1 to form clathrin coat.

Answer 417

NPXY signal grabs AP-2 to form clathrin coat.

Answer 418

Dynamin hydrolyses GTP to pinch off vesicle.

Answer 419

Vesicle is shed with Hsc70's help. ARF-GTP to ARF-GDP.

Answer 420

Rab interaction allows for SNARE complex formation at pH of 5 at endosome.

Answer 421

At acidic endosome, histidine on LDL-R beta-propeller becomes (+).

Answer 422

Ligand binding arm now binds to LDL-R beta propeller.

Answer 423

LDL is released.

Answer 424

has apoB hydrolyzed by protease.

Answer 425

has cholesterol esters exposed to cholestryl esterases.

Answer 426

intermediate filaments

Answer 427

protofilaments.

Answer 428

complete structures.

Answer 429

held together by strong covalent bonds, allowing for strength of the cytoskeleton.

Answer 430

held together by weak non-covalent bonds, allowing flexibility.

Answer 431

must avoid breaking from mere thermal motion.

Answer 432

form lateral connections with adjacent protofilaments.

Answer 433

assemble/disassemble only at the ends.

Answer 434

can assemble/disassemble in the middle.

Answer 435

of intermediate filaments form alpha helix coiled coils.

Answer 436

of actin and MTs are formed from globular monomers.

Answer 437

are the thinnest structures.

Answer 438

measure at 7 nm in width.

Answer 439

support the shape of the cell.

Answer 440

are made of actin monomers that form 3 chains that twist around each other.

Answer 441

has ATP binding site in cleft (facing (-) end) in center.

Answer 442

has a distinct polarity +/-.

Answer 443

has polarity due to electroactive aa side chains.

Answer 444

is positively charged.

Answer 445

is barbed.

Answer 446

is pointed.

Answer 447

breaks down and builds up rapidly.

Answer 448

changes rather slowly.

Answer 449

nucleation must occur, which is a slow process.

Answer 450

subunits at the plus end are competing for space.

Answer 451

ATP hydrolysis takes time to occur.

Answer 452

worsens lag time.

Answer 453

eliminates lag time.

Answer 454

doesn't have an effect.

Answer 455

allow nucleation to occur quicker.

Answer 456

allow structures to build anywhere.

Answer 457

target structures to areas needed by the cell.

Answer 458

by external signals.

Answer 459

by evil scientists.

Answer 460

help catalyze nucleation.

Answer 461

capture 2 actin molecules to begin nucleation.

Answer 462

continue to associate with actin at the plus end.

Answer 463

dissociate after nucleation.

Answer 464

is structurally similar to actin.

Answer 465

has a different plus end compared to actin.

Answer 466

allows actin monomers to bind at plus end.

Answer 467

remains bound to (-) end of actin polymer.

Answer 468

needs an activating factor to free it from accessory proteins that hold its active site out of orientation.

Answer 469

is most efficient at a 70 degree angle to preformed actin filament.

Answer 470

is associated with leading edge of migrating cells to allow cellular direction change.

Answer 471

anytime at the same rate.

Answer 472

quicker when in a filament.

Answer 473

quicker as a monomer.

Answer 474

more likely to exist in a filament.

Answer 475

more likely to exist as a monomer.

Answer 476

more likely to dissociate from the filament.

Answer 477

less likely to dissociate from the filament.

Answer 478

Now the filament has an ATP cap.

Answer 479

Now the filament has an ADP cap.

Answer 480

ADP hydrolysis occurs faster, allowing an ADP cap to form.

Answer 481

The world explodes.

Answer 482

makes me tired.

Answer 483

involves net addition at the minus end and net loss at the plus end simultaneously.

Answer 484

involves net addition at the plus end and net loss at the minus end simultaneously.

Answer 485

binds to actin subunits, preventing binding to (+) or (-) end.

Answer 486

this is because thymosin blocks the area of the protein that hooks on to the filament.

Answer 487

thymosin blocks ATP binding site.

Answer 488

decreases rate of elongation.

Answer 489

binds to plus side of actin monomer.

Answer 490

favors hydrolysation of ATP to ADP.

Answer 491

is thought to bind to some formins to "stage" for action on the polymer.

Answer 492

binds filaments forcing tight twisting in the structure.

Answer 493

helps add monomers to the plus end of the filament.

Answer 494

weakens the contacts between subunits.

Answer 495

makes actin-ADP dissociation easier.

Answer 496

makes actin-ATP association easier.

Answer 497

binds preferentially to actin-ADP units.

Answer 498

destroys new filaments moreso than old ones.

Answer 499

has effects blocked by tropomyosin.

Answer 500

increases rate of disassembly.

Answer 501

cytokinesis.

Answer 502

cleavage furrow.

Answer 503

11 parallel protofilaments.

Answer 504

13 parallel protofilaments.

Answer 505

15 parallel protofilaments.

Answer 506

is a microtubule organizing center.

Answer 507

is a centrosome in mammalian cells.

Answer 508

is on each end of a MT.

Answer 509

is a heterodimer.

Answer 510

is composed of 3 globular proteins, alpha, beta, gamma subunits.

Answer 511

has its globular proteins held together via noncovalent bonds.

Answer 512

has alpha and beta subunits.

Answer 513

has two nucleotide binding domains for GTP (alpha, beta).

Answer 514

GTP is bound at the intersection between the alpha and beta subunits, and can be hydrolyzed.

Answer 515

GTP is bound to the beta subunit, and can be hydrolyzed by the beta subunit itself.

Answer 516

Alpha subunit is a GTPase.

Answer 517

longitudinal

Answer 518

these contacts allow MTs to be stiff

Answer 519

tubulin-GTP binding to the plus end.

Answer 520

tubulin-GTP hydrolysis to tubulin-GDP while part of the filament.

Answer 521

tubulin-GDP causes curvature to form, weakening MT structure.

Answer 522

GTP caps can be formed if polymerization is faster than GTP hydrolyzation.

Answer 523

shrinking phase called catastrophe.

Answer 524

growing phase called rescue.

Answer 525

has a pair of centrioles.

Answer 526

is composed of fibrous centrosome matrix.

Answer 527

has about 50 gamma tubulins.

Answer 528

divides during interphase to aid with mitosis.

Answer 529

has many proteins in the matrix, that catalyze addition of tubulins.

Answer 530

is more abundant than alpha and beta units.

Answer 531

is involved in nucleation.

Answer 532

is formed from gamma tubulin and other proteins.

Answer 533

allows nucleation to occur.

Answer 534

binds the plus end of tubulin subunits to its minus end.

Answer 535

caps the minus end of the MTs.

Answer 536

bind to tubulin subunits to prevent binding to the polymer.

Answer 537

facilitate tubulin binding to the polymer.

Answer 538

cap the end of the MT to prevent subunit binding.

Answer 539

prevent binding of subunits to the polymer.

Answer 540

bind to the polymer to stabilize.

Answer 541

bind to subunits to prevent interaction with the polymer.

Answer 542

has motor activity.

Answer 543

attaches to the end of the MT to create a stabilizing cap.

Answer 544

pries apart the end of a MT.

Answer 545

does not interact with the end of the MT.

Answer 546

allows anaphase to occur.

Answer 547

can stabilize MT ends.

Answer 548

can be phosphorylated to be deactivated.

Answer 549

is not a MAP.

Answer 550

are plus end tracking proteins.

Answer 551

are plus end tubulin proteins.

Answer 552

can attach and stabilize the growing MT to different locations in the call.

Answer 553

accumulate and remain attached at the plus end.

Answer 554

are about 10 nm in width.

Answer 555

are the thickest filaments.

Answer 556

are required for correct cell functioning.

Answer 557

can have varied compositions.

Answer 558

are constructed only from a particular protein subunit.

Answer 559

can be constructed from keratin, vimentin, lamins, etc.

Answer 560

easy to break.

Answer 561

difficult to break.

Answer 562

different monomers.

Answer 563

assemble in nonpolar fashion.

Answer 564

two monomers form coiled-coil dimer.

Answer 565

each monomer has globular domain at each N & C terminus.

Answer 566

monomers have small, short alpha helical structure.

Answer 567

10 protofilaments made up of pentamers form intermediate filament.

Answer 568

8 protofilaments made up of tetramers form intermediate filament.

Answer 569

outer skin layer made of keratin that functions as a barrier.

Answer 570

support and anchor structures to maintain shape.

Answer 571

line the outside of the lining of the nuclear envelope.

Answer 572

provide strength to long axons of neurons.

Answer 573

actin, toward (+)

Answer 574

actin, toward (-)

Answer 575

MT, toward (+)

Answer 576

MT, toward (-)

Answer 577

is a large family of 37+ motor proteins.

Answer 578

typically refers to myosin II.

Answer 579

are all (-) end-directed.

Answer 580

is a two-headed dimer.

Answer 581

has alpha helices that form a coiled-coil tail.

Answer 582

has two small chains.

Answer 583

have heptad (7) aa repeat sequence.

Answer 584

have hydrophobic side chain interactions on 1st and 4th amino acids.

Answer 585

have hydrophobic side chain interactions on 2nd and 4th amino acids.

Answer 586

hydrophobic side chains weakly bind to form a superhelix.

Answer 587

are formed by bundles of myosin motor proteins that form a polar contractile unit.

Answer 588

have a bare zone in the middle of the filament that has no myosin.

Answer 589

has myosin going one way on one side and another way on the opposite side.

Answer 590

myosin III is used to make myosin thick filaments.

Answer 591

myosin shortens.

Answer 592

myosin and actin slide past each other.

Answer 593

myosin and actin shorten.

Answer 594

myosin filaments slide past each other.

Answer 595

are actually very large single cells.

Answer 596

are several cells lined up on a filament.

Answer 597

have majority of cytoplasm made up of myofibrils.

Answer 598

have most of cytoplasm filled with mitochondria.

Answer 599

have contractile units called sarcomeres.

Answer 600

are arrays of parallel and overlapping thick (myosin) and thin (actin) filaments.

Answer 601

span from Z disc to Z disc.

Answer 602

have capZ proteins that cap and stabilize myosin heads.

Answer 603

have capZ proteins that cap and stabilize actin heads.

Answer 604

span from Z disc to capZ to Z disc to capZ.

Answer 605

caps actin on (-) end.

Answer 606

caps actin on (+) end.

Answer 607

caps myosin on (-) end.

Answer 608

caps myosin on (+) end.

Answer 609

dark bands of actin.

Answer 610

dark bands of myosin.

Answer 611

light bands of actin.

Answer 612

light bands of myosin.

Answer 613

walk towards Z disc.

Answer 614

walk towards bare zone.

Answer 615

are driven by ~300 myosin heads that each have.

Answer 616

are driven by ~30 myosin heads that each have.

Answer 617

10%, 1/50th second

Answer 618

20%, 1/50th second

Answer 619

10% 1/100th second

Answer 620

20%, 1/100th second

Answer 621

myosin heads.

Answer 622

myosin coiled-coil tails.

Answer 623

actin filaments.

Answer 624

actin coiled-coil tails.

Answer 625

binds to actin and spans the length of it. Acts like a molecular ruler.

Answer 626

binds to myosin and spans the length of it. Acts like molecular ruler.

Answer 627

binds to actin and connects end to Z disc. Acts like molecular spring.

Answer 628

binds to myosin and connects end to Z disc. Acts like molecular spring.

Answer 629

muscle contraction; Trop I, Trop T, Trop C.

Answer 630

muscle contraction; Trop I, Trop T, Trop R.

Answer 631

muscle relaxation; Trop I, Trop T, Trop C.

Answer 632

muscle relaxation; Trop I, Trop T, Trop R.

Answer 633

along the groove of actin helix.

Answer 634

along the groove of myosin helix.

Answer 635

pulls tropomyosin out of groove.

Answer 636

allows tropomyosin back into the groove.

Answer 637

hydrolyzes tropomyosin.

Answer 638

phosphorylates tropomyosin.

Answer 639

SR releases Ca2+ which binds to Troponin C.

Answer 640

Tropomyosin moves out of its groove.

Answer 641

Myosin head can now bind to actin after ATP binding.

Answer 642

Myosin head can now bind to actin after GTP binding.

Answer 643

Binding and hydrolysis of ATP/GTP causes conformational change in converter domain.

Answer 644

Swinging of lever arm causes head to move along actin.

Answer 645

Myosin is attached to actin microfilament without a nucleotide.

Answer 646

Head is at 45 degree angle to filament.

Answer 647

Head is at 60 degree angle to filament.

Answer 648

ATP quickly binds and causes a conformational change in lever arm.

Answer 649

Myosin dissociates from actin.

Answer 650

As Ca2+ is taken up into SR by calcium P pump, Troponin I & T form IT complex.

Answer 651

ATPase myosin activity cleaves ATP to ADP and Pi.

Answer 652

Conformational change causes lever arm to swing 90 relative to filament, binds to actin.

Answer 653

Inorganic phosphate released, causing lever arm to return to 45 degree angle (the power stroke).

Answer 654

Myosin head loses ADP.

Answer 655

begins a few hours after death and dissapates 48-60 hours after death.

Answer 656

is caused by a lack of ATP.

Answer 657

involves myosin being "stuck" in position.

Answer 658

dissipates after thermal energy causes myosin to break down.

Answer 659

ends when enzymes involved in degradation break down myosin heads.

Answer 660

is sped up by cold.

Answer 661

is a motor protein.

Answer 662

mostly move vesicles and organelles toward the (-) end of MTs.

Answer 663

commonly refers to Kinesin II.

Answer 664

has a heavy chain on N terminus, the motor domain.

Answer 665

is involved in superfamily of at least 14 members.

Answer 666

binder domain.

Answer 667

linker region.

Answer 668

either motor head domain.

Answer 669

alpha helical tail.

Answer 670

Heads work in walking motion fueled by ATP.

Answer 671

Kinesin is typically bound to ADP, which will bind weakly to MT once contact made.

Answer 672

Kinesin-ADP becomes Kinesin-ATP.

Answer 673

Kinesin ATP will bind weakly to MT. Conformational change of ATP binding causes lagging strand to zip forward 8nm.

Answer 674

ATP hydrolyzed at on new lagging head.

Answer 675

New leading strand releases ADP and binds ATP with MT.

Answer 676

Lagging strand propelled forward.

Answer 677

Cool note. MT bound tightly by kinesin ATP, just like myosin II binds tightly to actin without nucleotide.

Answer 678

moves vesicles and organelles towards the center of the cell.

Answer 679

is involved in separation of chromatids during anaphase.

Answer 680

includes cytoplasmic dynein with 2 large head motor domains and 2 light domains.

Answer 681

includes complex axonemal dynein with 3 large heads and many light chains.

Answer 682

are the slowest motor proteins.

Answer 683

large motor head in a ring at C terminal domain.

Answer 684

has 6 AAA domains, 4 of which retain ATPase activity with one primary.

Answer 685

has tail that carries cargo.

Answer 686

has long coiled-coil stalk that binds MT.

Answer 687

ATP hydrolysis causes attachment of stalk to MT.

Answer 688

release of ADP and Pi leads to the large power stroke conformational change.

Answer 689

8nm steps toward (-) of MT.

	Criado por Ryan Pappal mais de 9 anos atrás

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Cell Bio - Exam 2

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