Cell Bio exam 2 study guide questions

Which organelle will use up oxygen and give off carbon dioxide and water? A.) lysosomes B.) Golgi C.) mitochondria D.) chloroplasts E.) ER

C.) mitochondria

Cellular respiration is best associated with the: A.) Golgi apparatus. B.) ribosome. C.) mitochondrion. D.) chloroplast. E.) microtubule.

C.) mitochondrion.

In plants, chloroplasts are necessary for: A.) respiration. B.) secretion. C.) photosynthesis. D.) storage. E.) movement

C.) photosynthesis.

T/F According to the endosymbiotic theory, eukaryotes became the mitochondria and chloroplasts.

False

T/F Because mitochondria contain their own DNA, mitochondria could build their own structures and live independently if outside the eukaryotic cell.

False

T/F Cellular respiration is, essentially, the opposite of photosynthesis.

False

T/F Clathrin is responsible for capturing specific molecules for transport in coated vesicle structures.

False

T/F Electrons gain energy as they move through the electron transport chain.

False

T/F Fermentation produces more ATP molecules than aerobic respiration does.

False

T/F Mitochondria produce most of the energy used in bacteria.

False

T/F The mitochondria of plants contain thylakoids.

False

Mitochondria are/synthezise: A) structures involved in the breakdown of ATP B) organelles involved in the synthesis of proteins C) involved in producing ATP for cellular energy D) synthesize proteins for use outside the cell

C) involved in producing ATP for cellular energy

In a cell capable of regulated secretion, what are the three main classes of proteins that must be separated before they leave the trans Golgi network?

(1) destined for lysosomes (2) destined for secretory vesicles (3) destined for immediate delivery to cell surface.

An individual transport vesicle: (a) contains only one type of protein in its lumen. (b)will fuse with only one type of membrane. (c) is endocytic if it is traveling toward the plasma membrane. (d) is enclosed by a membrane with the same lipid and protein composition as the membrane of the donor organelle.

(b)will fuse with only one type of membrane.

Which cellular location would you expect to find ribosomes translating mRNAs that encode ribosomal proteins? (a) The nucleus (b) On the rough ER (c) In the cytosol (d) In the lumen of the ER

(c) In the cytosol

Which of the following organelles are not part of the endomembrane system? (a)Golgi apparatus (b)the nucleus (c) mitochondria (d)lysosomes

(c) mitochondria

T/F Alcohol is a by-product of fermentation by yeast.

True

T/F Eukaryotic cells have both nucleus and mitochondria which each have double membranes.

True

Choose the correct statements about exocytotic pathways below: a.) Adaptins bind to the cargo receptors of the ER. b.) Coated vesicles help shape the membrane into a bud vesicle. c.) GTP binding proteins help to secure the clathrin coat to the vesicle membrane. d.) t-SNARES are recognized by complementary v-SNARES located on the target membrane. e.) COP coated vesicles transport molecules between Golgi and the ER as well as within the Golgi itself

a.) Adaptins bind to the cargo receptors of the ER. b.) Coated vesicles help shape the membrane into a bud vesicle. e.) COP coated vesicles transport molecules between Golgi and the ER as well as within the Golgi itself

Glycolysis occurs in the _______ of a cell. a.) Nucleus b.) Chloroplast c.) Mitochondrion d.) Cytosol

d.) Cytosol

The earliest atmosphere of Earth is not believed to have contained oxygen. Which cellular component would not have been useful at that time? a.) Chloroplast b.) Nucleus c.) plasma membrane d.) Mitochondrion

d.) Mitochondrion

What is the importance of photosynthesis to organisms other than plants? a.) All other organisms require oxygen for life processes. b.) The sugars made during photosynthesis are building blocks of DNA. c.) All cells must have chloroplasts in order to survive. d.) Photosynthesis captures energy that other organisms access when they eat plants or organisms that eat plants.

d.) Photosynthesis captures energy that other organisms access when they eat plants or organisms that eat plants

Which of the following functions does the SRP do? a.) binding to the ribosome. b.) bringing the ribosome to the SRP receptor. c.) stopping translocation. d.) bringing the growing protein to the translocation

d.) bringing the growing protein to the translocation

NAD++ is an energy carrier in living organisms that couples a.) oxygen and carbon dioxide. b.) ATP and water. c.) photosynthesis and metabolism. d.) the Krebs cycle.

d.) the Krebs cycle.

If a lysosome breaks, what protects the rest of the cell from lysosomal enzymes?

lysosomal enzymes are all acid hydrolases, which have optimal activity at the low pH (about 5.0) found in the interior of lysosomes. If a lysosome were to break, the acid hydrolases would find themselves at pH 7.2, the pH of the cytosol, and would therefore do little damage to cellular constituents.

Which of the following statements about vesicle budding from the Golgi is false? (a) Clathrin molecules are important for binding to and selecting cargos for transport. (b) Adaptins interact with clathrin. (c) Once vesicle budding occurs, clathrin molecules are released from the vesicle. (d) Clathrin molecules act at the cytosolic surface of the Golgi membrane.

(a) Clathrin molecules are important for binding to and selecting cargos for transport.

Which of the following statements about membrane-enclosed organelles is true? (a) In a typical cell, the area of the endoplasmic reticulum membrane far exceeds the area of plasma membrane. (b) The nucleus is the only organelle that is surrounded by a double membrane. (c) Other than the nucleus, most organelles are small and thus, in a typical cell, only about 10% of a cell's volume is occupied by membrane-enclosed organelles; the other 90% of the cell volume is the cytosol. (d) The nucleus is the only organelle that contains DNA.

(a) In a typical cell, the area of the endoplasmic reticulum membrane far exceeds the area of plasma membrane.

What is the role of the nuclear localization sequence in a nuclear protein? (a) It is bound by cytoplasmic proteins that direct the nuclear protein to the nuclear pore. (b) It is a hydrophobic sequence that enables the protein to enter the nuclear membranes. (c) It aids in protein unfolding so that the protein can thread through nuclear pores. (d) It prevents the protein from diffusing out of the nucleus through nuclear pores.

(a) It is bound by cytoplasmic proteins that direct the nuclear protein to the nuclear pore.

Which of the following statements about secretion is true? (a) The membrane of a secretory vesicle will fuse with plasma mbr when it discharges its contents to the cell's exterior. (b) Vesicles for regulated exocytosis will not bud off the trans Golgi network until the appropriate signal has been received from the cell. (c) The signal sequences of proteins destined for constitutive exocytosis ensure their packaging into the correct vesicles. (d) Proteins destined for constitutive exocytosis aggregate as a result of the acidic pH of the trans Golgi network.

(a) The membrane of a secretory vesicle will fuse with plasma mbr when it discharges its contents to the cell's exterior.

A small-molecule drug binds to LDL receptors when they are bound to cholesterol and does not alter the conformation of the LDL receptor's intracellular domain. If in vitro experiments demonstrate that addition of the drug increases the affinity of LDL for cholesterol and prevents cholesterol from dissociating from the LDL receptor even in acidic conditions, What reasonable prediction of what may happen when the drug is added to cells? (a) Cytosolic cholesterol levels will remain unchanged relative to normal cells. (b) Cytosolic cholesterol levels will decrease relative to normal cells. (c) The LDL receptor will remain on the plasma membrane. (d)The uncoating of vesicles will not occur.

(b) Cytosolic cholesterol levels will decrease relative to normal cells.

Which of the following statements about the endoplasmic reticulum (ER) is false? (a) The ER is the major site for new membrane synthesis in the cell. (b) Proteins to be delivered to the ER lumen are synthesized on smooth ER. (c) Steroid hormones are synthesized on the smooth ER. (d) ER membrane is contiguous with the outer nuclear membrane.

(b) Proteins to be delivered to the ER lumen are synthesized on smooth ER.

The figure shows the organization of a protein that normally resides in the plasma membrane. The boxes labeled 1 and 2 represent membrane-spanning sequences and the arrow represents a site of action of signal peptidase. Given this diagram, which of the following statements must be true? (a)The N-terminus of this protein is cytoplasmic. (b)The C-terminus of this protein is cytoplasmic. (c)The mature version of this protein will span the membrane twice, with both the N and C-termini in the cytoplasm. (d)None of the above.

(b)The C-terminus of this protein is cytoplasmic.

Which of the following statements is true? (a) The signal sequences on mitochondrial proteins are usually C-terminal. (b) Most mitochondrial proteins are not imported from the cytosol but are synthesized inside the mitochondria. (c) Chaperone proteins in mitochondria facilitate movement proteins across the outer and inner mitochondrial mbrs. (d) Mitochondrial proteins cross the membrane in their native, folded state.

(c) Chaperone proteins in mitochondria facilitate movement proteins across the outer and inner mitochondrial mbrs.

Most proteins destined to enter the endoplasmic reticulum; (a) are transported across the membrane after their synthesis is complete. (b) are synthesized on free ribosomes in the cytosol. (c) begin to cross the membrane while still being synthesized. (d) remain within the endoplasmic reticulum.

(c) begin to cross the membrane while still being synthesized.

A drug that blocks the ability of Ran to exchange GDP for GTP. What is the most likely effect of this drug on nuclear transport? (a)Nuclear transport receptors would be unable to bind cargo. (b)Nuclear transport receptors would be unable to enter the nucleus. (c)Nuclear transport receptors would be unable to release their cargo in the nucleus. (d)Nuclear transport receptors would interact irreversibly with the nuclear pore fibrils.

(c)Nuclear transport receptors would be unable to release their cargo in the nucleus.

Your friend has just joined a lab that studies vesicle budding from the Golgi and has been given a cell line that does not form mature vesicles. He wants to start designing some experiments but wasn't listening carefully when he was told about the molecular defect of this cell line. He's too embarrassed to ask and comes to you for help. He does recall that this cell line forms coated pits but vesicle budding and the removal of coat proteins don't happen. Which of the following proteins might be lacking in this cell line? (a) clathrin (b)Rab (c)dynamin (d)adaptin

(c)dynamin

After isolating the rough ER from the rest of the cytoplasm, you purify the RNAs attached to it. Which of the following proteins do you expect the RNA from the rough endoplasmic reticulum to encode? (a) Soluble secreted proteins (b) ER membrane proteins (c) Plasma membrane proteins (d) All of the above

(d) All of the above

Which of the following statements about disulfide bond formation is false? (a) Disulfide bonds do not form under reducing environments. (b) Disulfide bonding occurs by the oxidation of pairs of cysteine side chains on the protein. (c) Disulfide bonding stabilizes the structure of proteins. (d) Disulfide bonds form spontaneously within the ER because the lumen of the ER is oxidizing.

(d) Disulfide bonds form spontaneously within the ER because the lumen of the ER is oxidizing.

Which reflects the appropriate order through which a protein destined for the plasma membrane travels? (a) lysosome → endosome → plasma membrane (b) ER → lysosome → plasma membrane (c) Golgi → lysosome → plasma membrane (d) ER → Golgi → plasma membrane

(d) ER → Golgi → plasma membrane

You are interested in Fuzzy, a soluble protein that functions within the ER lumen. Given that information, which of the following statement must be true? (a) Fuzzy has a C-terminal signal sequence that binds to SRP. (b) Only one ribosome can be bound to the mRNA encoding Fuzzy during translation. (c) Fuzzy must contain a hydrophobic stop-transfer sequence. (d) Once signal sequence from Fuzzy has been cleaved, signal peptide will be ejected into ER membrane and degraded.

(d) Once signal sequence from Fuzzy has been cleaved, signal peptide will be ejected into ER membrane and degraded.

Which of the following protein families are not involved in directing transport vesicles to the target membrane? (a) SNAREs (b) Rabs (c) tethering proteins (d) adaptins

(d) adaptins

N-linked oligosaccharides on secreted glycoproteins are attached to: (a) nitrogen atoms in the polypeptide backbone. (b) serine or threonine in the sequence Asn-X-Ser/Thr. (c) the N-terminus of the protein. (d) the asparagine in the sequence Asn-X-Ser/Thr.

(d) the asparagine in the sequence Asn-X-Ser/Thr.

Name two types of protein modification that can occur in the ER but not in the cytosol.

- disulfide bond formation - glycosylation

For each sentences, choose one of the two options enclosed in square brackets to make a TRUE statement. -New plasma membrane reaches the plasma membrane by the [regulated/constitutive] exocytosis pathway. -New plasma membrane proteins reach the plasma membrane by the [regulated/constitutive] exocytosis pathway. -Insulin is secreted from pancreatic cells by the [regulated/constitutive] exocytosis pathw Theay. -The interior of the trans Golgi network is [acidic/alkaline]. -Proteins that are constitutively secreted [aggregate/do not aggregate] in the trans Golgi network.

-constitutive -constitutive -regulated -acidic -do not aggregate

- Proteins are transported out of a cell via the _1_ or exocytic pathway. Fluid and macromolecules are transported into the cell via the _2_pathway. All proteins being transported out of the cell pass through the endoplasmic reticulum _3_and then_4_. Transport vesicles link organelles of the _5_system. The formation of _6_in the endoplasmic reticulum stabilizes protein structure. New plasma membrane proteins reach the plasma membrane by the _7_exocytosis pathway. Insulin is secreted from pancreatic cells by the _8_exocytosis pathway. The interior of the trans Golgi network is acidic. Proteins that are constitutively secreted do _9_ aggregate in the trans Golgi network. a. Golgi apparatus b. endocytic c. translocator d. Golgi e. endomembrane f. disulfide bonds g. constitutive h. regulated i. not j.__

1. a. Golgi apparatus 2. b. endocytic 3. c. translocator 4. d. Golgi 5. e. endomembrane 6. f. disulfide bonds 7. g. constitutive 8. h. regulated 9. i. not

Match the following organelles with their function: a.Mitochondria b.Endoplasmic reticulum c.Nucleus d.Lysosome e.Endosome f.Peroxisome g.Golgi apparatus _____ quality control of mRNA _____ location of phosphorylation _____ responsible for detoxifying organic molecules (liver cells) _____ houses and protects genetic material _____ responsible for modification and sorting of proteins and lipids _____ location of ATP synthesis _____ responsible for sorting endocytosed materials _____ site of degradation and digestion _____ responsible for oxidizing toxic molecules _____ location of phospholipid assembly

1. c. Nucleus- quality control of mRNA 2. a. Mitochondria- location of phosphorylation 3. f. Peroxisome- responsible for detoxifying organic molecules (liver cells) 4. c. Nucleus- houses and protects genetic material 5. g. Golgi apparatus- responsible for modification and sorting of proteins and lipids 6. a. Mitochondria- location of ATP synthesis 7. e. Endosome- site of degradation and digestion 8. d. Lysosome - responsible for oxidizing toxic molecules 9. f. Peroxisome- location of phospholipid assembly

-Plasma membrane proteins are inserted into the membrane in the _1_. The address information for protein sorting in a eucaryotic cell is contained in the _2_of the proteins. Proteins enter the nucleus in their _3_ form. Proteins that remain in the cytosol do not contain a _4_. Proteins are transported into the Golgi apparatus via _5_. The proteins transported into the endoplasmic reticulum by _6_ are in their _7_ form. a. protein translocators b.sorting signal c.folded d.endoplasmic reticulum e.endosome f.amino acid sequence g.transport vesicles h.unfolded i.Golgi apparatus j.plasma membrane

1. d. endoplasmic reticulum 2. f. amino acid sequence 3. c. folded 4. b. sorting signal 5. g. transport vesicles 6. a. protein translocators 7. h. unfolded

- Eucaryotic cells are continually taking up materials from the extracellular space by the process of endocytosis. One type of endocytosis is _1_, which uses _2_ proteins to form small vesicles containing fluids and molecules. After these vesicles have pinched off from the plasma membrane, they will fuse with the _3_, where materials that are taken into the vesicle are sorted. A second type of endocytosis is_4_, which is used to take up large vesicles that can contain microorganisms and cellular debris. Macrophages are especially suited for this process, as they extend _5_ (finger-sheetlike projections of their plasma membrane) to surround the invading microorganisms. a.Chaperone b.Golgi apparatus c.pseudopods d.Cholesterol e.rough ER f.Clathrin g.phagocytosis h.SNARE i.endosome j.pinocytosis

1. j. pinocytosis 2. f. Clathrin 3. i. endosome 4. g. phagocytosis 5. c. pseudopods

The "powerhouse" of the cell is the: A.) chloroplast. B.) mitochondria. C.) Golgi apparatus. D.) ribosome. E.) centriole.

B.) mitochondria.

The endosymbiotic hypothesis argues that prokaryotes became some of the organelles of early eukaryotic cells. This would be supported by what evidence? A.) vacuoles can "come and go" across the plasma membrane. B.) mitochondria and chloroplasts have their own DNA. C.) Mitochondria and chloroplasts are nearly identical to some free living prokaryotes. D.) mitochondria and chloroplasts have their own DNA AND are nearly identical to some free living prokaryotes.

D.) mitochondria and chloroplasts have their own DNA AND are nearly identical to some free living prokaryotes.

Both plant and animal cells have mitochondria because they both: A.) have photosynthesis. B.) have a large vacuole. C.) have ER D.) need ATP for energy

D.) need ATP for energy

Which of these is best associated with plant cells? A.cilia/flagella B.chloroplasts/centrioles C.round shape D.small vesicles E.chloroplast/cell wall

E.chloroplast/cell wall

Which organelle will give off oxygen and use up carbon dioxide? A.Golgi B.rough ER C.lysosomes D.mitochondria E.chloroplasts

E.chloroplasts

T/F Mitochondria are bounded by a double membrane.

True

T/F Most components of the endocytic vesicle membrane eventually are returned to the plasma membrane for reuse.

True

T/F Oxidative phosphorylation includes an electron transport chain.

True

T/F Receptor proteins that are incorporated into an endosome can be retrieved back to the membrane domain it originated from.

True

T/F Transport vesicles can bud from the trans Golgi network to fuse with the plasma membrane in a process called constitutive exocytosis.

True

Which of the following are essential in the formation of a clathrin coated transport vesicle? a.) Clathrin b.) adaptin c.) COPI d.) snares

a.) Clathrin

Which of the following participate in the formation of a vesicle? a.) Dynamin b.) SNARES c.) Clathrin d.) Adaptin

a.) Dynamin c.) Clathrin d.) Adaptin

Which statements are true for the import of protein in an organelle? a.) Proteins are recognized by a receptor and actively transported into the nucleus. b.) Signal sequences are found on some proteins to transport them from the ER to the cytosol. c.) Proteins are delivered directly from the cytosol to the peroxisomes. d.) vSNARES and tSNARES tightly bound conformation remove the water from between the membrane and allowing the membrane of the vesicles to fuse. e.) The ER removes the oligosaccharides that were added on the proteins in the trans-golgi network.

a.) Proteins are recognized by a receptor and actively transported into the nucleus. c.) Proteins are delivered directly from the cytosol to the peroxisomes. e.) The ER removes the oligosaccharides that were added on the proteins in the trans-golgi network.

The nuclear envelope= a.) contains nuclear pores that allow inport and export to the nucleus. b.) formed from two concentric membranes which are able to act as binding sites for chromomes. c.) contains a nuclear lamina involved in structural support. d.) contains an outer membrane continuous with the ER.

a.) contains nuclear pores that allow inport and export to the nucleus. b.) formed from two concentric membranes which are able to act as binding sites for chromomes. c.) contains a nuclear lamina involved in structural support. d.) contains an outer membrane continuous with the ER.

Which of the following occur in the ER lumen regarding proteins? a.) fold. b.) degrade. c.) form disulfide bonds. d.) are"decorated" with oligosaccharide chains.

a.) fold. c.) form disulfide bonds. d.) are"decorated" with oligosaccharide chains.

The first stage of the breakdown of sugar molecules for energy is a.) glycolysis. b.) oxidative phosphorylation. c.) the carbon cycle. d.) the Krebs cycle.

a.) glycolysis.

The process that produces ATP from sugars and fats begins with a.) glycolysis. b.) photosynthesis. c.) the electron transport chain. d.) the Krebs cycle.

a.) glycolysis.

An enzyme added to a cell that degrades snares in all membranes, then vesicles leaving ER will= a.) recognize but not fuse with the target membrane. b.) fuse with the first membrane with which it comes in contact. c.) not recognize nor fuse with any membrane. d.) not occur because the vesicle will not be able to form.

a.) recognize but not fuse with the target membrane.

The ER signal sequence is guided to the ER membrane with the aid of a a.) signal-recognition particle (SRP) b.) translocation channel c.) SRP receptor d.) Membrane bound ribosome

a.) signal-recognition particle (SRP) c.) SRP receptor

The Golgi apparatus performs which of the following functions? a.) sorting b.) phosphorylation c.) degradation d.) modification of proteins e.) assembly of lipids

a.) sorting b.) phosphorylation d.) modification of proteins e.assembly of lipids

The burning pain in your muscles during strenuous exercise is a result of a.) the build up of lactic acid during fermentation. b.) signals sent to the nervous system by O2-starved cells. c.) the accumulation of pyruvate in the absence of oxidative phosphorylation. d.) the lack of ATP needed to regulate the pain receptors in your muscle cells.

a.) the build up of lactic acid during fermentation.

The Krebs cycle takes place in a.) the mitochondrial matrix. b.) the cytosol. c.) the thylakoid membrane. d.) the outer mitochondrial membrane.

a.) the mitochondrial matrix.

The photosynthetic light reactions occur in the a.) thylakoid membrane. b.) stroma. c.) cytosol. d.) nucleus.

a.) thylakoid membrane.

Which of the following is involved in snare docking? a.) ATP b.) A pulling attraction between membranes c.) Dynamin d.) GTP

b.) A pulling attraction between membranes

Which of the following molecules carryies electrons that will be used to reduce other molecules in an electron transport chain? a.) ATP b.) NADH c.) CO2 d.) ADP

b.) NADH

Which of the following elements does not become incorporated into the sugars produced by photosynthesis? a.) Carbon b.) Phosphorous c.) Hydrogen d.) Oxygen

b.) Phosphorous

The three stages of aerobic catabolism are a.) photosynthesis, glycolysis, and oxidative phosphorylation. b.) glycolysis, the Krebs cycle, and oxidative phosphorylation. c.) glycolysis, fermentation, and the Krebs cycle. d.) photosynthesis, the Krebs cycle, and fermentation.

b.) glycolysis, the Krebs cycle, and oxidative phosphorylation.

The function of the Calvin cycle is to a.) capture energy from sunlight. b.) synthesize sugars. c.) produce pyruvate. d.) break down molecules in order to release energy.

b.) synthesize sugars.

Examining the effects of mutations on nuclear pore, in which cases will nuclear proteins still be able to enter the nucleus (include those where function will be impaired, but still able to occur): a.) The nuclear localization signal is mutated on a nuclear protein. b.) The nuclear transport receptor cannot bind to the nuclear protein. c.) A limited amount of kinase is available in the cell to hydrolyze the GTP. d.) Nuclear transport proteins pass through with nuclear proteins but can't be recycled to the cytosol.

c.) A limited amount of kinase is available in the cell to hydrolyze the GTP. d.) Nuclear transport proteins pass through with nuclear proteins but can't be recycled to the cytosol.

What proteins are directly involved in the transportation of cargo in a clathrin-coated vesicle? a.) Dynamin b.) Adaptins c.) Cargo receptors d.) t-SNARES

c.) Cargo receptors

During the process of photosynthesis, plants capture light energy and store it in the form of a.) pyruvate. b.) stroma. . c.) chemical bonds. d.) thylakoid disks

c.) chemical bonds.

During photosynthesis, energized electrons flow a.) from Photosystem I to Photosystem II. b.) from the reaction center to the antenna complex. c.) from Photosystem II to Photosystem I. d.) from the stroma to the intermembrane space.

c.) from Photosystem II to Photosystem I.

During exercise, the increase in respiration rate and heartbeat speed are driven by the need for a.) oxygen in fermentation. b.) carbon dioxide in human lungs. c.) oxygen in muscle cell mitochondria. d.) oxygen in dark reactions.

c.) oxygen in muscle cell mitochondria.

What membrane-enclosed organelles are thought to have arisen by invagination of the plasma membrane and are part of the Endomembrane System? a.Endosomes b.The Golgi Apparatus c.Mitochondria d.Endoplasmic Reticulum e.Chloroplasts

d.Endoplasmic Reticulum