Each of the following processes is associated with one or more specific eukaryotic organelles. In each case, identify the organelle or organelles.

Biosynthesis of testosterone or estrogen

A. It is associated with peroxisomes and mitochondria.

B. It is associated with peroxisomes.

C. It is associated with mitochondria.

D. It is associated with lysosome.

E. It is associated with smooth endoplasmic reticulum.

F. It is associated with Golgi.

G. It is associated with rough endoplasmic reticulum and Golgi.

E. It is associated with smooth endoplasmic reticulum.

Each of the following processes is associated with one or more specific eukaryotic organelles. In each case, identify the organelle or organelles.

Degradation of damaged organelles

A. It is associated with peroxisomes.

B. It is associated with Golgi.

C. It is associated with mitochondria.

D. It is associated with rough endoplasmic reticulum and Golgi.

E. It is associated with peroxisomes and mitochondria.

F. It is associated with lysosome.

G. It is associated with endoplasmic reticulum.

H. It is associated with smooth endoplasmic reticulum.

F. It is associated with lysosome.

Each of the following processes is associated with one or more specific eukaryotic organelles. In each case, identify the organelle or organelles.

Glycosylation of membrane proteins

A. It is associated with endoplasmic reticulum.

B. It is associated with lysosome.

C. It is associated with rough endoplasmic reticulum and Golgi.

D. It is associated with smooth endoplasmic reticulum.

E. It is associated with peroxisomes and mitochondria.

F. It is associated with peroxisomes.It is associated with mitochondria.

G. It is associated with Golgi.

C. It is associated with rough endoplasmic reticulum and Golgi.

Each of the following processes is associated with one or more specific eukaryotic organelles. In each case, identify the organelle or organelles.

Sorting of lysosomal proteins from secretory proteins

A. It is associated with endoplasmic reticulum.

B. It is associated with mitochondria.

C. It is associated with peroxisomes and mitochondria.

D. It is associated with smooth endoplasmic reticulum.

E. It is associated with lysosome.It is associated with peroxisomes.

F. It is associated with rough endoplasmic reticulum and Golgi.

G. It is associated with Golgi.

G. It is associated with Golgi.

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. lysosome

B. endosome

C. secretory vesicle

D. Golgi apparatus

D. Golgi apparatus

The endoplasmic reticulum is a site for

A. N-linked glycosylation of polypeptides.

B. addition of lipid residues.

C. drug detoxification by catalase.

D. potassium storage in muscle cells.

E. N-linked glycosylation of polypeptides and drug detoxification by catalase.

A. N-linked glycosylation of polypeptides.

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

A. KDEL signals

B. botulinum toxin

C. clatherin

D. stabilin

E. mannose-6-phosphate

E. mannose-6-phosphate

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 does not possess a signal peptide for localization within the lumen of the rough endoplasmic reticulum.

B. protein possesses a signal for localization within the Golgi apparatus.

C. protein was not translated by the ribosomes.

D. all of the above

B. protein possesses a signal for localization within the Golgi apparatus.

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. regulated secretion.

B. zymogen secretion.

C. polarized secretion.

D. constitutive secretion.

E. none of the above

C. polarized secretion.

Which of the following statements is false regarding phagocytosis?

A. It is a method used predominantly by amoeba to obtain food.

B. It is mediated by clathrin at the plasma membrane.

C. It involves ingestion of large particles by the cell.

D. It involves the projection of pseudopodia.

E. In vertebrates, macrophages and neutrophils possess this ability.

B. It is mediated by clathrin at the plasma membrane.

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

A. recycling of receptors.

B. transcytosis.

C. transport to late endosome for digestion.

D. transport to late endosome for digestion and recycling of receptors.

E. transcytosis, transport to late endosome for digestion, and recycling of receptors.

E. transcytosis, transport to late endosome for digestion, and recycling of receptors.

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

A. chronic fatigue syndrome.

B. adult-onset diabetes.

C. tuberculosis.

D. Huntington's disease.

E. Tay-Sachs disease.

E. Tay-Sachs disease.

Peroxisomes

A. are bounded by double membranes.

B. possess amylase activity.

C. are not derived from the endoplasmic reticulum.

D. possess acid phosphatase activity.

E. all of the above

C. are not derived from the endoplasmic reticulum.

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

A. smooth endoplasmic reticulum

B. peroxisomes

C. mitochondria

D. lysosomes

E. all of the above

B. peroxisomes

A protein that is N-glycosylated is expected to

A. eventually become an endosome.

B. be localized in the Golgi body.

C. be localized in the endoplasmic reticulum.

D. be secreted from the cell.

E. eventually become a peroxisome.

D. be secreted from the cell.

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. the Golgi apparatus.

C. chloroplasts.

D. peroxisomes.

E. lysosomes.

E. lysosomes.

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

A. stems.

B. cotyledons.

C. phloem and xylem.

D. leaves.

E. root nodules.

E. root nodules.

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. fertilization of animal eggs and rheumatoid arthritis

E. fertilization of animal eggs, rheumatoid arthritis, and autophagy

D. fertilization of animal eggs and rheumatoid arthritis

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

A. Golgi complexes

B. peroxisomes

C. endosomes

D. rough endoplasmic reticulum

E. smooth endoplasmic reticulum

B. peroxisomes

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. catalase.

B. hexokinase.

C. cytochrome c oxidase.

D. glucose-6-phosphatase.

E. ATPase.

A. catalase.

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. endoplasmic reticulum

C. extracellular matrix

D. trans Golgi complex

E. inner membrane of mitochondria

D. trans Golgi complex

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. Lysosomal enzymes were not phosphorylated in the rER.

B. There is a lack of mannose-6-phosphatase activity.

C. The ER was unable to produce lysosomal vesicles.

D. A proton gradient within vesicles was not generated.

E. There is a mutation in all hydrolase genes that results in loss of the signal peptide.

B. There is a lack of mannose-6-phosphatase activity.

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. constitutive secretion.

B. transport secretion.

C. consistent secretion.

D. intracellular secretion.

E. regulated secretion

E. regulated secretion

Microsomes are

A. structures observed in cyanobacteria.

B. organelles through which electrons cannot pass.

C. too small to be seen with an electron microscope.

D. artifacts generated during homogenization of cells.

E. organelles of eukaryotic cells.

D. artifacts generated during homogenization of cells.

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. incorporate radioactive amino acids into the protein.

B. incorporate the appropriate mannose-6-phosphate groups.

C. do nothing; all proteins go through the ER.

D. incorporate the appropriate lipid groups into the lipoprotein.

E. incorporate the appropriate DNA sequence with the proper signal.

E. incorporate the appropriate DNA sequence with the proper signal.

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

A. do not make the appropriate anchor protein.

B. are synthesizing cytoplasmic proteins.

C. have a defect in ribosomal proteins that allow attachment to the ER.

D. have a signal/trafficking error.

E. all of the above

B. are synthesizing cytoplasmic proteins.

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

A. Golgi body.

B. peroxisomes.

C. lysosomes.

D. endosomes.

E. Neither lysosomes nor Golgi body are part of the endomembrane system.

B. peroxisomes.

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. sER → Golgi → secretory vesicle → environment

B. rER → secretory vesicle → Golgi → environment

C. rER → Golgi → secretory vesicle → environment

D. nucleus → rER → Golgi → secretory vesicle → environmentr

E. ER → Golgi → sER → nucleus → environment

C. rER → Golgi → secretory vesicle → environment

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

A. microsomes

B. non-clathrin vesicles

C. lysosomes

D. clathrin-coated vesicles

E. endosomes

D. clathrin-coated vesicles

Oxidation of very long fatty acids occurs in the

A. lysosomes.

B. residual bodies.

C. peroxisomes.

D. smooth endoplasmic reticulum.

E. mitochondria.

C. peroxisomes.

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

A. liver

B. connective tissue

C. skin

D. muscle

E. blood

A. liver

Uptake of low-density lipoproteins (LDLs) occurs by

A. receptor-mediated endocytosis.

B. bulk-phase endocytosis.

C. pinocytosis.

D. facilitated transport.

E. simple diffusion.

A. receptor-mediated endocytosis.

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

A. contain sialic acid.

B. be glycosylated only.

C. be glycosylated and contain amino acid modifications.

D. be identical.

E. be shorter in length.

B. be glycosylated only.

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

A. microsome.

B. vacuole.

C. lysosome.

D. triskelion.

E. endosome.

B. vacuole.

The plant cell organelle analogous to the endosome is the

A. peroxisome.

B. glycoxysome.

C. provacuole.

D. lysosome.

E. none of the above

C. provacuole.

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

A. residual bodies.

B. cholesterol uptake.

C. mixed-function oxidases.

D. phagocytosis by specifically vertebrate white blood cells.

E. ATP-dependent calcium ATPases.

C. mixed-function oxidases.

A researcher is attempting to isolate rough ER microsomes using ultracentrifugation. Which of the following would indicate contamination of the rough ER with another organelle?

A. ribosomes

B. catalase

C. membranes

D. glycosylated proteins

B. catalase

The endoplasmic reticulum is a site for

A. drug detoxification by catalase.

B. addition of lipid residues.

C. N-linked glycosylation of polypeptides.

D. degradation of foreign material brought into the cell by phagocytosis.

E. potassium storage in muscle cells.

C. N-linked glycosylation of polypeptides.

Comparing cells synthesizing secretory proteins and cells secreting steroid hormones, the cells synthesizing the steroid hormones have

A. more smooth ER.

B. equal amounts of smooth and rough ER, but fewer lysosomes.

C. equal amounts of smooth and rough ER, but more lysosomes.

D. equal amounts of smooth and rough ER.

E. more rough ER.

A. more smooth ER.

Each of the following is an endoplasmic reticulum function except

A. the assembly of multimeric proteins.

B. addition of carbohydrate to proteins to make glycoproteins.

C. the export of protein that cannot be folded into the cytoplasm for destruction.

D. peptide folding.

E. All are endoplasmic reticulum functions.

E. All are endoplasmic reticulum functions.

In the Golgi complex, __________.

A. the anterograde transport system is used to move vesicles back to the ER

B. proteins are synthesized

C. proteins are N-glycosylated

D. carbohydrate side chains of glycoproteins are modified

D. carbohydrate side chains of glycoproteins are modified

A protein that is N-glycosylated is expected to be

A. a peroxisome enzyme.

B. localized in the Golgi body.

C. imported into a cell by endocytosis.

D. retained in the endoplasmic reticulum.

E. secreted from the cell.

E. secreted from the cell.

Using genetic engineering techniques, which of the following would you do to a protein that normally is constitutively secreted to make it accumulate in the ER?

A. add an amino acid that would get a mannose-6-phosphate group added to its carbohydrate

B. fuse it to GFP

C. add a KDEL sequence near its C-terminus

D. mutate one of the asparagines that is normally glycosylated to an alanine, which is not glycosylated

E. None of these would cause the protein to accumulate in the ER.

C. add a KDEL sequence near its C-terminus

Each of the following is part of the endomembrane system, except

A. peroxisomes.

B. endosomes.

C. lysosomes.

D. zymogen granules.

E. Golgi complex.

A. peroxisomes.

A protein that is normally localized in the cytoplasm has been engineered so that it will be secreted from the cell instead. Which of the following represents the most likely pathway for the protein after it has been completely synthesized?

A. rER \to Golgi \to sER \to cytoplasm \to environment

B. rER \to secretory vesicle \to Golgi \to environment

C. cytoplasm \to rER \to Golgi \to secretory vesicle \to environment

D. sER \to Golgi \to secretory vesicle \to environment

E. rER \to Golgi \to secretory vesicle \to environment

E. rER \to Golgi \to secretory vesicle \to environment

Which of the following molecules forms the coat during receptor-mediated endocytosis-coated pit formation?

A. tethering protein

B. T-SNARE

C. mannose-6-phosphate

D. clathrin

E. caveolin

D. clathrin

In receptor-mediated endocytosis, each of the following is a fate for the receptors and/or vesicle contents except

A. release from the vesicle into the nucleus.

B. digestion in a lysosome.

C. transcytosis.

D. recycling to the plasma membrane.

E. All are possible fates.

A. release from the vesicle into the nucleus.

Uptake of low-density lipoproteins (LDLs) occurs by

A. receptor-mediated endocytosis.

B. phagocytosis.

C. simple diffusion.

D. pinocytosis.

E. facilitated transport.

A. receptor-mediated endocytosis.

Statins are drugs that are administered to inhibit the biosynthesis of cholesterol in the liver, and thus are used to lower blood plasma cholesterol levels in order to decrease patient risk of atherosclerosis and associated diseases such as myocardial infarction (heart attack). Which of the following components of the endomembrane system is the site of action of statin drugs?

A. the ER

B. lysosomes

C. the nucleus

D. the Golgi complex

A. the ER

Which of the following statements is false regarding phagocytosis?

A. It is mediated by clathrin at the plasma membrane.

B. It is used by macrophages and neutrophils to ingest bacteria.

C. It is used by amoebae to ingest food.

D. It involves the projection of pseudopods.

E. It can ingest large particles.

A. It is mediated by clathrin at the plasma membrane.

The low pH of lysosomes is established by

A. superoxide dismutases.

B. acid hydrolases.

C. \betha-glucuronidases.

D. catalases.

E. ATP-dependent proton pumps.

E. ATP-dependent proton pumps.

Which statement is NOT true of plant vacuoles?

A. They may contain hydrolytic enzymes.

B. They resemble lysosomes in their biogenesis.

C. They are used for secretion.

D. They may contain pigment to impart color to flowers.

C. They are used for secretion.

The plant cell organelle most analogous to animal cell lysosomes is the

A. microsome.

B. glyoxysome.

C. leaf peroxisome.

D. endosome.

E. vacuole.

E. vacuole.

Peroxisomes

A. possess mannose phosphotransferase activity.

B. exist only in algae and photosynthetic cells in plants.

C. are not derived from the endoplasmic reticulum.

D. are bounded by double membranes.

E. possess acid phosphatase activity.

C. are not derived from the endoplasmic reticulum.

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

A. late endosomes

B. lysosomes

C. mitochondria

D. smooth endoplasmic reticulum

E. peroxisomes

E. peroxisomes

Each of the following organelles is part of the endomembrane system except

A. the rough endoplasmic reticulum.

B. the Golgi complex.

C. the peroxisome.

D. the smooth endoplasmic reticulum.

E. the endosome.

C. the peroxisome.

You have isolated two fractions containing similar-sized vesicles by centrifugation. You suspect one fraction contains lysosomes and the other contains peroxisomes. To confirm that a fraction contains peroxisomes, you would assay for which of the following enzymes?

A. a protease

B. acid phosphatase

C. ribonuclease

D. \betha-glucuronidase

E. catalase

E. catalase

In animal cells, oxidation of very long fatty acids occurs in

A. the smooth endoplasmic reticulum.

B. mitochondria.

C. residual bodies.

D. peroxisomes.

E. lysosomes.

D. peroxisomes.

Endocytosis moves materials _____ a cell via _____.

A. into ... membranous vesicles

B. into ... a transport protein

C. into ... facilitated diffusion

D. out of ... membranous vesicles

E. out of ... diffusion

A. into ... membranous vesicles

A white blood cell engulfing a bacterium is an example of _____.

A. pinocytosis

B. facilitated diffusion

C. receptor-mediated endocytosis

D. phagocytosis

E. exocytosis

D. phagocytosis

What protein does the term coated vesicle refer to?

A. the receptors in the membrane of the vesicle

B. the adaptor proteins surrounding the vesicle

C. the clathrin that forces the vesicle to invaginate

D. the ligand bound to the receptor

C. the clathrin that forces the vesicle to invaginate

What is the trigger for the invagination of the vesicle?

A. occupied receptors accumulating in the coated pits

B. ligands binding to the receptors

C. polymerization of clathrin

D. the activity of dynamin

A. occupied receptors accumulating in the coated pits

What is the initial fate of an uncoated vesicle?

A. It fuses with an early endosome.

B. The internalized ligands are separated from the receptors and sorted.

C. It fuses with a lysosome.

D. The receptors are recycled to the membrane.

A. It fuses with an early endosome.

Once of the processes linked to receptor-mediated endocytosis is transcytosis. When might this mechanism be useful?

A. in transporting antibodies from mother’s milk from an infant’s stomach into the bloodstream

B. to expose receptors to the opposite side of the cell

C. in immune cell transport of invading viruses

D. to expel substances from lysosomes that are indigestable

A. in transporting antibodies from mother’s milk from an infant’s stomach into the bloodstream

How is receptor-mediated endocytosis (RME) different from pinocytosis and phagocytosis?

A. Unlike pinocytosis and phagocytosis, RME is not a saturable process.

B. Unlike pinocytosis, RME is specific; unlike phagocytosis, RME is for small particles.

C. RME does not require energy.

D. Unlike pinocytosis, RME is for dissolved particles; unlike phagocytosis, RME is specific.

B. Unlike pinocytosis, RME is specific; unlike phagocytosis, RME is for small particles.

Which organelle plays a role in intracellular digestion?

A. chloroplast

B. ribosome

C. lysosome

D. plasmodesma

E. Golgi apparatus

C. lysosome

Anterograde movement of transition vesicles is from __________.

A. the rough ER to the cis Golgi

B. the trans Golgi to secrete at the plasma membrane

C. the rough ER to the trans Golgi

D. the cis Golgi to the trans Golgi

A. the rough ER to the cis Golgi

Maturation of a lysosome occurs when __________.

A. late endosomes acidify to activate the acid hydrolases

B. material is digested and sorted and buds off the lysosome

C. acid hydrolases are packaged into vesicles and bud off the trans Golgi

D. early endosomes fuse with endocytosed vesicles

A. late endosomes acidify to activate the acid hydrolases

What types of substances would move retrograde to the rough ER?

A. proteins with the amino acid sequence R-X-R

B. rough ER retention tags

C. amino acids from the lysosomes to be used in protein synthesis

D. proteins with a KDEL retrieval tag

D. proteins with a KDEL retrieval tag

What process involves proteins in vesicles being held at the plasma membrane until the cell is signaled to release them?

A. constitutive secretion

B. early endosome packaging

C. exocytosis

D. regulated secretion

D. regulated secretion

Imagine that you are a cellular biologist studying the processing of a lysosomal protein. When you mutate a specific amino acid in its sequence, the protein accumulates in the trans cisternae of the Golgi complex and is NOT transported to the lysosome. What is a possible cause of this?

A. The cells lack an enzyme to phosphorylate mannose residues.

B. The mutation has created an ER retrieval tag.

C. The protein is being recognized as misfolded by the ERAD system.

D. A glycosylation site has been removed.

D. A glycosylation site has been removed.