Deck 12: The Endomembrane System and Peroxisomes

Question 1

All of the following are part of the core oligosaccharide side chain in the ER,except

A)N-acetyl glucosamine.
B)erythrose.
C)mannose.
D)glucose.
E)both choices A and C

Answer 1

B

Question 2

Bacterial proteins were radioactively labeled and fed to phagocytic cells.The proteins within the phagocytic cell became increasingly more radioactive over time.This observation is the result of the activity of

A)mitochondria.
B)chloroplasts.
C)lysosomes.
D)peroxisomes.
E)the Golgi apparatus.

Answer 2

C

Question 3

A protein is destined to be secreted from a cell.In which of the following organelles would you expect to find the protein first?

A)endosome
B)Golgi apparatus
C)lysosome
D)secretory vesicle

Answer 3

B

Question 4

The endoplasmic reticulum is a site for

A)potassium storage in muscle cells.
B)drug detoxification by catalase.
C)N-linked glycosylation of polypeptides.
D)addition of lipid residues.
E)both choices B and C

Question 5

You want to engineer a yeast cell to manufacture and secrete a bacterial protein product.To do this properly,you need to make certain that

A)the appropriate signal sequence is present.
B)plenty of clathrin-coated pits may be formed.
C)mannose-6-phosphate is added to the protein.
D)the yeast cell is capable of phagocytosis.
E)all of the above

Question 6

During receptor-mediated endocytosis,the ultimate fate of the vesicle and/or its contents include(s)

A)transcytosis.
B)transport to late endosome for digestion.
C)recycling of receptors.
D)only choices B and C
E)choices A, B, and C

Question 7

The continuous release of mucus by the epithelial cells lining the respiratory tract is an example of

A)regulated secretion.
B)constitutive secretion.
C)the mucus response.
D)the formation of clathrin-coated pits.
E)phagocytosis.

Question 8

Which of the following is associated with extracellular digestion via release of the contents of lysosomes directly to the environment?

A)fertilization of animal eggs
B)rheumatoid arthritis
C)autophagy
D)only choices A and B
E)choices A, B, and C

Question 9

Lysosomal storage diseases are the result of deficiencies in lysosomal proteins.An example of one such disorder is

A)adult-onset diabetes.
B)tuberculosis.
C)Huntington's disease.
D)chronic fatigue syndrome.
E)Tay-Sachs disease.

Question 10

Which of the following organelles is associated with the ability to catabolize alkanes found in oil and petroleum products?

A)mitochondria
B)smooth endoplasmic reticulum
C)peroxisomes
D)lysosomes
E)all of the above

Question 11

Which of the following organelles are not part of the endomembrane system?

A)peroxisomes
B)Golgi complexes
C)smooth endoplasmic reticulum
D)endosomes
E)rough endoplasmic reticulum

Question 12

Peroxisomes

A)are not derived from the endoplasmic reticulum.
B)are bounded by double membranes.
C)possess acid phosphatase activity.
D)possess amylase activity.
E)all of the above

Question 13

A radioactively labeled protein is made by cells and followed through the various organelles in the secretory pathway.After six hours,all of the radioactivity is still primarily in the Golgi apparatus.This suggests that the

A)protein was not translated by the ribosomes.
B)protein does not possess a signal peptide for localization within the lumen of the rough endoplasmic reticulum.
C)protein possesses a signal for localization within the Golgi apparatus.
D)all of the above

Question 14

A protein that is N-glycosylated is expected to

A)be secreted from the cell.
B)be localized in the endoplasmic reticulum.
C)be localized in the Golgi body.
D)eventually become an endosome.
E)eventually become a peroxisome.

Question 15

You are isolating cell fractions using a variety of centrifuge techniques.You have two very similar fractions but at this point are unable to discern which fraction is peroxisomes and which is lysosomes.As a result,you need to test the fractions for unique enzyme activities.If you are looking for peroxisomes,one enzyme activity you can test for is

A)hexokinase.
B)ATPase.
C)glucose-6-phosphatase.
D)cytochrome c oxidase.
E)catalase.

Question 16

In plants,peroxisomes associated with nitrogen fixation in legumes can be found in great abundance in

A)leaves.
B)stems.
C)phloem and xylem.
D)cotyledons.
E)root nodules.

Question 17

Which of the following molecules stabilizes the cell membrane during coated pit formation?

A)mannose-6-phosphate
B)KDEL signals
C)clatherin
D)botulinum toxin
E)stabilin

Question 18

Which of the following statements is false regarding phagocytosis?

A)It involves ingestion of large particles by the cell.
B)It involves the projection of pseudopodia.
C)It is a method used predominantly by amoeba to obtain food.
D)It is mediated by clathrin at the plasma membrane.
E)In vertebrates, macrophages and neutrophils possess this ability.

Question 19

In a longitudinal section of a nerve cell,at the presynaptic site you note a variety of vesicles that are anchored to the plasma membrane.The vesicles must be specialized for

A)constitutive secretion.
B)regulated secretion.
C)polarized secretion.
D)zymogen secretion.
E)none of the above

Question 20

All of the following are true about botulinum toxin/Botox except

A)The toxin is one of the most potent toxins known.
B)Botox is a SNARE protein.
C)It can be used therapeutically to stop muscle spasms.
D)It has been used to remove wrinkles caused by muscle contractions.
E)It has potential use as a migraine headache treatment.

Question 21

All of the following are part of the endomembrane system,except the

A)Golgi body.
B)endosomes.
C)lysosomes.
D)peroxisomes.
E)Neither C nor D are part of the endomembrane system.

Question 22

Compared with the trans-Golgi proteins,the cis-Golgi proteins would

A)be identical.
B)be shorter in length.
C)be glycosylated and contain amino acid modifications.
D)contain sialic acid.
E)be glycosylated only.

Question 23

You are working with cells and observe transport of your target protein within a cell.You suspect that sorting conforms to the SNARE hypothesis.You,therefore,expect

A)to eventually identify vesicle-SNAP receptors.
B)to eventually identify transport-SNAP receptors.
C)an association with clatherin-coated pits.
D)the protein molecules were internalized by phagocytosis.
E)all of the above

Question 24

Of the following cell types,the greatest concentration of high-density lipoprotein (HDLs)would be associated with ________ cells.

A)skin
B)muscle
C)connective tissue
D)blood
E)liver

Question 25

All of the following are unique to plant cells except

A)leaf peroxisomes.
B)glyoxysomes.
C)nodule peroxisomes.
D)peroxisomes.
E)chloroplasts.

Question 26

All of the following statements about cellular trafficking are true except

A)COPII-coated vesicles move materials from ER to Golgi.
B)COPI-coated vesicles move materials from Golgi to the secretory vesicle.
C)movement may be mediated by microtubules.
D)v-SNAREs occur in vesicles; t-SNAREs occur on target sites.
E)tethering proteins mediate docking between target and vesicle.

Question 27

Which of the following cellular processes has/have been linked to cancer/tumor formation?

A)autophagy
B)EGF desensitization
C)caveolae uptake
D)NMDA receptors
E)both choices A and B

Question 28

The plant cell organelle analogous to the endosome is the

A)provacuole.
B)lysosome.
C)peroxisome.
D)glycoxysome.
E)none of the above

Question 29

The organelle of plant cells that is analogous to the lysosome in animal cells is the

A)vacuole.
B)triskelion.
C)microsome.
D)endosome.
E)lysosome.

Question 30

Oxidation of very long fatty acids occurs in the

A)mitochondria.
B)peroxisomes.
C)lysosomes.
D)smooth endoplasmic reticulum.
E)residual bodies.

Question 31

If you were looking within a cell for organized clathrin structures,you would find them associated with which of the following structures?

A)lysosomes
B)trans Golgi complex
C)endoplasmic reticulum
D)inner membrane of mitochondria
E)extracellular matrix

Question 32

Regulatory secretion of hormones would be associated with ________ at the transface of the Golgi.

A)endosomes
B)lysosomes
C)clathrin-coated vesicles
D)non-clathrin vesicles
E)microsomes

Question 33

Cells of the pancreas produce and directly release enzymes to the digestive system. The type of secretory mechanism associated with the pancreatic cells is

A)transport secretion.
B)regulated secretion.
C)constitutive secretion.
D)intracellular secretion.
E)consistent secretion.

Question 34

Pharmacogenetics is a new field of study that arose from the study of

A)cholesterol uptake.
B)mixed-function oxidases.
C)ATP-dependent calcium ATPases.
D)phagocytosis by specifically vertebrate white blood cells.
E)residual bodies.

Question 35

Ribosomes that do not anchor to the surface of the rough endoplasmic reticulum during translation most probably

A)are synthesizing cytoplasmic proteins.
B)have a defect in ribosomal proteins that allow attachment to the ER.
C)have a signal/trafficking error.
D)do not make the appropriate anchor protein.
E)all of the above

Question 36

In a lysosomal storage disease,the hydrolases of lysosomes are released from the cells,rather than being isolated into vesicles.What is one possible mechanism for this result?

A)A proton gradient within vesicles was not generated.
B)The ER was unable to produce lysosomal vesicles.
C)Lysosomal enzymes were not phosphorylated in the rER.
D)There is a lack of mannose-6-phosphatase activity.
E)There is a mutation in all hydrolase genes that results in loss of the signal peptide.

Question 37

Using the techniques of genetic engineering,you design a cytoplasmic protein you want to accumulate within the ER of yeast cells. To accomplish this goal,you need to

A)do nothing; all proteins go through the ER.
B)incorporate the appropriate mannose-6-phosphate groups.
C)incorporate the appropriate DNA sequence with the proper signal.
D)incorporate radioactive amino acids into the protein.
E)incorporate the appropriate lipid groups into the lipoprotein.

Question 38

Uptake of low-density lipoproteins (LDLs)occurs by

A)simple diffusion.
B)bulk-phase endocytosis.
C)facilitated transport.
D)receptor-mediated endocytosis.
E)pinocytosis.

Question 39

Microsomes are

A)too small to be seen with an electron microscope.
B)artifacts generated during homogenization of cells.
C)organelles through which electrons cannot pass.
D)organelles of eukaryotic cells.
E)structures observed in cyanobacteria.

Question 40

You have genetically engineered a yeast cell to make a protein that will ultimately be secreted from the cell. If all is functioning well,in which order (from first to last)do you expect to find the protein in the cell until it is secreted?

A)rER → Golgi → secretory vesicle → environment
B)rER → Golgi → sER → nucleus → environment
C)nucleus → rER → Golgi → secretory vesicle → environment
D)sER → Golgi → secretory vesicle → environment
E)rER → secretory vesicle → Golgi → environment

Question 41

Distinguish among the following: endocytosis,pinocytosis,and phagocytosis.

Question 42

Coated vesicles known as ________ are thought to potentially be associated with cholesterol uptake and/or have a role in signal transduction.

Question 43

________ act as proton pumps and keep the internal proton concentration of lysosomes high.

Question 44

________ is the molecule associated with receptor-mediated endocytosis that "coats" the vesicle until it is released.

Question 45

V-________ and t-________ mediate final docking between target and vesicle.

Question 46

________ is the organelle associated with the functions of steroid biosynthesis,carbohydrate metabolism,and drug detoxification.

Question 47

Describe how Botox can be used in the treatment of wrinkles and muscle spasms at low concentrations.

Question 48

If you were wanting to synthesize a particular protein in plants that allowed it to accumulate within the plant vacuole,how would you design your chimeric protein to concentrate within this vacuole? What features of the plant vacuole are unique?

Question 49

The investigation of the movement of proteins and lipids to their appropriate location within a cell is known as ________.

Question 50

Exocytosis is stimulated by regional increases in ________ concentration.

Question 51

A ________ is a short sequence of amino acids that targets a protein for translation across the endoplasmic reticulum.

Question 52

The ________ is the organelle involved in the posttranslational modification of proteins and sorting of proteins to various intracellular and extracellular compartments.

Question 53

Design an experiment that will allow you to follow a protein from the endoplasmic reticulum,Golgi complex,and secretion vesicles to the outside of the cell.How will this differ if the protein is localized within lysosomes?

Question 54

A ________ is the organelle that fuses with endosomes and supplies hydrolytic enzymes necessary for the digestion of the materials within the endosome.

Question 55

The chronic use of the ________ class of drugs can result in decreased effectiveness of antibiotics,anticoagulants,and steroids.

Question 56

________ are proteins associated with clathrin-coated vesicles that are involved in the binding of vesicles to specific receptors.

Question 57

Peroxisomes and the smooth endoplasmic reticulum are both organelles associated with the detoxification of harmful substances.How do these two organelles differ with regard to this process?