Biology 263
Cell Biology
Dr. Joel B. Piperberg
May 5, 2010
Final Exam
Name _________________________________
Page #1
I. Multiple Choice. Fill in the best answer on the answer sheet.
1. Dolichol phosphate ____________.
a. is a phospholipid
b. donates a block of carbohydrates to secretory proteins as they enter the RER lumen
c. is a membrane protein
d. and its attached carbohydrates flip from the cytoplasmic leaflet of the RER membrane to the leaflet
facing the RER lumen
e. a, b and d
2. Which enzyme would be least likely to be found in a lysosome?
a. b, d and e b. acid phosphatase c. catalase d. N-acetylhexosaminidase
3. Which organelle is observable only in a plant cell?
a. mitochondria
b. vacuole
c. glyoxysome
d. peroxisome
e. -glucosidase
e. c and d
4. Storage diseases like Hunter's syndrome and glycogenosis disease may result from ______ enzymes.
a. nonfunctional mitochondrial
c. nonfunctional lysosomal
e. c and d
b. missing peroxisomal
d. missing lysosomal
5. The function of the glycocalyx is ____________.
a. to act as a lubricant
b. to mediate cell-cell interactions
c. to act as a molecular sieve keeping materials from the cell surface
d. b and c
e. to initiate cell division
6. Which of the following directly or indirectly helps to open calcium channels in the smooth
endoplasmic reticulum?
a. an activated G protein
b. IP4 c. diacylglycerol
d. phospholipase C
e. a and d
7. What second messenger appears to be responsible for relieving the pain of angina?
a. CO b. nitric oxide c. monoamine oxidase d. NO
e. b and d
8. Which second messenger is produced by phospholipase C?
a. DAG
b. protein kinase C
c. a and d
d. IP3
e. diacyglyceric acid
9. Which word or words below is not associated with an RTK?
a. insulin
b. tyrosine
c. cAMP
d. transautophosphorylation
e. a and d
10. What can trigger the secretion of histamine and/or the contraction of muscle cells?
a. d and e
c. uptake of Ca2+ ions into SER
e. release of Ca2+ ions by
calmodulin
b. release of Na+ ions
d. release of Ca2+ ions into cytoplasm
11. Which of the following can be activated indirectly by the binding of inositol triphosphate to an SER
channel protein?
a. protein kinase A b. adenylate cyclase c. phospholipase C d. protein kinase C e. b and c
12. Cells can respond to steroid hormones by ___________.
a. altering nucleic acids
c. altering the activity of metabolic enzymes
b. altering gene expression
d. destroying peptide hormones
e. b and c
13. Which of the following is known to activate protein kinase C under at least some circumstances?
Biology 263
Cell Biology
Dr. Joel B. Piperberg
May 5, 2010
Final Exam
Name _________________________________
Page #2
a. phorbol esters b. Ca2+ ions c. diacylglycerol
d. a, b and c e. b and c
14. Which of the following directly produces a second messenger?
a. phosphorylase kinase b. adenylate lipase C c. guanylate cyclase d. c and e
e. PLC
15. What is the net gain in ATPs when 22 molecules of glucose are processed aerobically in a cell with
high energy requirements?
a. 792
b. 380
c. 836
d. 36
e. 38
16. How many carbons from 45 original glucose molecules enter the Krebs cycle when a cell operates
anaerobically?
a. 180
b. 270
c. 4
d. 6
e. none
17. How many ATPs are made from 36 original glucose molecules when a cell operates anaerobically?
a. 36
b. 1368
c. none
d. 1296
e. 72
18. In what part of the cell can peroxisomes form?
a. b, c and d
c. GERL
b. endoplasmic reticulum
d. in the Golgi apparatus
e. c and d
19. Radiolabeled glycerol is given to growing secretory cells. Over which of the following structures
would silver grains first appear?
a. rough ER
b. Golgi apparatus
c. secretory vesicles
d. a and e
e. smooth ER
20. Patients with I-cell disease __________
a. may lack receptors for mannose-6-phosphate in carbohydrates attached to lysosomal enzymes
b. may lack the enzymes that add mannose-6-phosphate to the carbohydrates of lysosomal enzymes
c. synthesize lysosomal enzymes without properly marking them as lysosomal enzymes
d. are unable to place peroxisomal enzymes properly within peroxisomes
e. a, b and c
21. Which word(s) below is(are) most closely associated with the collagen cables found in the corneal stroma?
a. perpendicular
b. fantastic
c. orthogonal
d. random
e. a and c
22. Which organelle is most prominent in the heterotrophic tissues of a plant like the endosperm?
a. peroxisomes b. lysosomes
c. glyoxysomes
d. contractile ring
e. centrioles
23. The last sugars added to dolichol phosphate are added in what location?
a. in the RER lumen b. in the SER lumen c. in the Golgi d. in the cytoplasm
e. on the ribosome
24. What enzyme is responsible for carbon fixation from the atmosphere in C3 plants?
a. Rubisco
b. acid phosphatase c. PEP carboxylase
d. ATP synthase
e. catalase
25. Which of the following happens after the SRP binds to the signal peptide?
a. Protein synthesis temporarily accelerates.
d. Ribosomes are conveyed to the SER.
b. Protein synthesis is temporarily suspended.
e. b and c
c. Ribosomes are conveyed to the RER.
26. What is thought to be the most common enzyme on Earth?
a. acid phosphatase b. Ribisco c. ribulose bisphosphate carboxylase
27. Where are proteins destined for the cytoplasm synthesized?
d. b and c e. PEP carboxylase
Biology 263
Cell Biology
Dr. Joel B. Piperberg
May 5, 2010
Final Exam
Name _________________________________
Page #3
a. on RER-bound ribosomes b. on free ribosomes c. on SER d. b and c e. Golgi apparatus
28. In order for a protein to end up in a lysosome, which of the following things would it need to have
as part of its initial primary structure?
a. a signal peptide b. a signal peptidase c. a stop-transfer sequence d. a 3'-end e. a and c
29. Which of the cell adhesion molecules below binds to a short sequence of sugars found on
glycoprotein oligosaccharides?
a. calmodulins
b. calpains
c. cadherins
d. adherins
e. selectins
30. A scientist isolates two specific mRNAs. One codes for the enzyme cheneyase, an enzyme that shoots
old men who are ostensibly his friends in the face, is often mistaken for Darth Vader and will not shut up;
the other codes for the enzyme specterase, an older enzyme that cannot decide which party it wants to be a
member of (oops! One should never end a sentence with a preposition). Both mRNAs are placed in a test
tube with RER vesicles stripped of their ribosomes, free ribosomes and precursors for protein synthesis.
When the protein synthesis reaction is complete, specterase is found in the liquid portion of the test tube
outside the vesicles; cheneyase is found inside the vesicles. What can one conclude about the two proteins?
a. Cheneyase is a secretory protein; specterase is a domestic protein.
b. Cheneyase is a domestic protein; specterase is a secretory protein.
c. Both proteins are secretory.
d. Both proteins are for domestic use.
e. Specterase diffuses into the vesicle after synthesis; cheneyase is an intrinsic membrane protein.
31. Which of the following sequences is most likely to be part of a signal peptide of a secretory protein.
Refer to the diagram of amino acid R groups on the page 9 of this test for help.
a. — gly - asp - met - glu - asp - gly - lys - arg - met —
b. — cys - arg - glu - lys - lys - arg - gly - met - asp —
c. — arg - leu - asp - lys - phe - glu - arg - pro - leu —
d. — leu - asp - ser - thr - glu - arg - aspN - gluN – met —
e. — asp - gly - leu - ile - met - pro - phe - val – met —
32. Which name below would be the name of an enzyme in the RER, Golgi or SER that is responsible
for adding sugars to growing oligosaccharide chains attached to the proteins passing through it?
a. sialylpeptidase b. d and e c. peptidyltransferase d. glycosyltransferase e. glucosyltransferase
33. Which of the following occurs when ATP is broken into an ADP and a phosphate group?
a. Energy is consumed
c. a, b and d
e. an hydrolysis reaction
b. Water is released.
d. a condensation-dehydration reaction
34. What molecule is formed when electrons drop off of the end of the mitochondrial electron transport chain?
a. NADPre
b. O2
c. NADre
d. H2O
e. CO2
35. What molecule carries four carbons at one point during aerobic respiration?
a. b and e
b. succinyl CoA
c. citric acid
d. NADre
e. acetyl CoA
36. Which event(s) occur(s) during the glucose mobilization (pump priming) stage of glycolysis?
a. c and e
b. A molecule of acetyl CoA transfers 2 carbons to a 4-carbon molecule.
c. Two molecules of ATP are produced.
d. A 6-carbon sugar is produced with 2 phosphate groups attached to 2 carbons in the molecule's center.
e. Glucose is changed into a compound that is readily cleaved into two 3-carbon phosphorylated units.
Biology 263
Cell Biology
Dr. Joel B. Piperberg
May 5, 2010
Final Exam
Name _________________________________
Page #4
37. Which statement about glycolysis is true?
a. It uses molecular oxygen.
d. b, c and e
b. It occurs in animal cell cytoplasm.
e. Glycolysis results in the net production of 2 ATPs.
c. Every living creature on Earth can carry out glycolysis.
38. What would happen in a cell if the electron transport chain were blocked?
a. NADre levels would increase.
d. FADox levels would decrease.
b. NADox levels would decrease.
e. a, b and d
c. There would be a net increase in oxygen.
39. You are studying some photosynthetic bacteria found in the sulfur pools of Yellowstone Park. They
contain only one photosystem and yet seem to be able to carry out both cyclic and non-cyclic
photophosphorylation. The sulfur in the pools is found in various forms, including H2S (hydrogen sulfide),
an electron-rich compound. How could the bacteria carry on photosynthesis with just one photosystem?
a. none of the other answers
b. They acquire electrons from water to replace those stored in NADPre.
c. They acquire electrons from water to replace those stored in NADre.
d. They acquire electrons from hydrogen sulfide to replace those stored in NADPre.
e. They make ATP whether they are carrying on cyclic or non-cyclic photophosphorylation.
40. You are conducting an experiment in photosynthesis. You have radioactively labeled the oxygen in a
compound and have observed that this oxygen is found later in the air surrounding the plant. What
compound was labeled?
a. water
b. carbon monoxide
c. starch
d. carbon dioxide
e. glucose
41. According to chemiosmosis, the energy stored in ATP by mitochondrial electron transport is
generated when ___________.
a. ATP synthetase produces NADPre in addition to ATP
b. electron transport drives a transmembrane proton (H+) pump that establishes a steep H+ gradient
c. electrons are transported magnetically
d. energy is stored in an electrochemical gradient between the intercristal space and the matrix
e. b and d
42. Which of the following molecules is likely to have recently donated electrons to another molecule?
a. ATP
b. FADre
c. FADox
d. NADPre
e. b and d
43. What is the name given to carbohydrates bound to asparagine residues on a secretory protein?
a. N-linked carbohydrates b. proteoglycans c. a and d d. O-linked carbohydrates e. glycoproteins
44. Which enzyme would be least likely to be located in a peroxisome?
a. DNase
b. amino acid oxidase
c. b, d and e
d. catalase
e. urate oxidase
45. Some of the molecules of electron transport chains accept electrons while others accept electrons
and hydrogen ions. This is significant because ____________.
a. it explains how these molecules can transport H+ ions for the purpose of setting up an H+ gradient
b. it explains how the energy that helps to make ATP during chemiosmosis is generated
c. a and b
d. it explains how electrons are added to FADre
e. it explains why Russia can't be seen from my house
46. Which statement below about cyclic photophosphorylation is false?
Biology 263
Cell Biology
Dr. Joel B. Piperberg
May 5, 2010
Final Exam
Name _________________________________
Page #5
a. ATP is produced from the electron derived from the Photosystem II reaction center.
b. O2 is produced when H2O is split.
c. a and b
d. The electrons from the Photosystem I reaction center end up back in Photosystem I.
e. Electrons from Photosystem I drive the production of ATP.
47. The importance of the Krebs (citric acid) Cycle in cell metabolism is that it __________.
a. makes important biochemical intermediates
c. makes NADPre
e. a and b
b. makes NADre
d. uses up ATP
48. Given that glycolysis, Krebs cycle and electron transport are regulated by allosteric enzymes that
control the reactions, what do you think happens to phosphofructokinase, one of the first enzymes in
the glycolytic pathway, or in the pathway when ATP levels are very high?
a. ATP is not found at its allosteric site and it works more quickly. d. Pyruvate production is lowered.
b. It is inhibited and begins to work more slowly.
e. b and d
c. It denatures.
49. The lollipop structures are __________.
a. b, c and d
c. ATP synthase molecules
b. found on thylakoid membranes d. found on the inner mitochondrial membrane
e. b and d
50. What characteristic of the signal peptide allows it to penetrate the RER membrane easily?
a. It is approximately 30 amino acids long.
d. It is largely made up of hydrophobic amino acids.
b. Its sequence is recognized by the GERL
e. It is degraded before transport.
c. The 9 - 12 amino acids on each end of the signal peptide tend to be hydrophobic.
51. Which of the following is a function of the smooth endoplasmic reticulum?
a. It adds sugars to carbohydrate chains on presumptive secretory proteins.
b. It can add amino acid segments to proteins.
c. It can, in some cells, sequester calcium ions.
d. It can, in some cells, chemically alter amino acids previously inserted into polynucleotides.
e. a and c
52. What may account for differences in the appearance of RER and SER?
a. the presence of ribosomes on SER
d. the distribution of ribosomal binding sites
b. the relative amounts of certain proteins
e. b and d
c. the relative amounts of certain steroids
53. In which organelle would most secretory proteins receive their final glycosylation?
a. RER
b. secretory vesicles
c. Golgi apparatus
d. SER
e. a and d
54. Fermentation permits continuous glycolysis in animals because ____________.
a. it serves to recycle NADre, which is needed for glycolysis
b. it serves to recycle NADox, which is needed for glycolysis
c. there is a net increase in the production of NADPox
d. lactic acid is produced recycling NADox
e. b and d
55. What is the name of the cytoskeletal element associated with zonulae adherens?
a. keratin
b. actin
c. tubulin
d. b and e e. microfilaments
56. The mRNA for a well-known secretory protein is isolated and placed in a test tube in the presence of
all the substances required for in vitro protein synthesis. The sequence of the protein produced in
Biology 263
Cell Biology
Dr. Joel B. Piperberg
May 5, 2010
Final Exam
Name _________________________________
Page #6
vitro is then compared to the sequence of the purified secretory protein from the cell. The amino acid
sequences of the two proteins are not the same. What is the explanation?
a. A short chain of mostly hydrophilic amino acids was removed from the N-terminal end of the
polypeptide in the test tube before it was analyzed.
b. A short chain of mostly hydrophobic amino acids was chopped off the C-terminal end of the
protein in the test tube before it was analyzed.
c. The mRNA was cleaved after being translated in the intact cell.
d. A largely hydrophobic segment at the N-terminal end of the polypeptide is cut off and degraded by
the signal peptidase in the protein secreted by the cell and then purified.
e. none of the above
57. A plant cell is injected with a low molecular weight fluorescent molecule called fluorescein. After a
short period of time, adjacent cells are seen to be fluorescing just like the originally injected cell.
The explanation is that the cells ___________.
a. are connected by plasmodesmata
d. were damaged by the injection procedure
b. are connected by gap junctions
e. are connected by hemidesmosomes
c. are joined by gap junctions & plasmodesmata
58. Which metabolic pathway probably evolved last?
a. Krebs cycle
c. cyclic photophosphorylation
b. noncyclic photophosphorylation d. glycolysis
e. fermentation
59. How would one determine the time it takes for the proteins destined for secretion to be synthesized,
processed and finally secreted and elucidate the pathway the protein follows at the same time?
a. b and c
c. pulse-chase experiment
e. b, c and d
b. labeling with radioactive amino acids
d. liquid scintillation counting
60. What controls the sequence of carbohydrates on oligosaccharides attached to secretory proteins?
a. whatever carbohydrates are close to the proteins
b. the sequence of glycosyltransferases in the chloroplasts
c. the arrangement of glycosyltransferases in the RER, SER and Golgi apparatus
d. the sequence of nucleotides in the nucleotide sugars
e. b and c
61. ________ attach cells to _________.
a. Hemidesmosomes, a noncellular surface
b. Hemidesmosomes, neighboring cells
c. Spot desmosomes, a noncellular surface e. a and d
d. Belt desmosomes, neighboring cells
62. What changes can be made in a secretory protein after any part of it has entered the ER?
a. removal of the signal sequence
b. addition of sugars from nucleotide sugar donors to the trimmed sugar core donated originally by a
phospholipid
c. addition of amino acids to the carbohydrates donated to the protein by dolichol phosphate
d. a and b
e. a, b and c
63. What is the name of a cell junction that contains keratin filaments?
a. c and d
b. zonula occludens
c. maculae adherens
d. spot desmosomes
e. belt desmosome
Biology 263
Cell Biology
Dr. Joel B. Piperberg
May 5, 2010
Final Exam
Name _________________________________
Page #7
64. You mix secretory and domestic protein mRNA, ribosomes, naked RER vesicles that have been
stripped of their ribosomes and everything else you need to synthesize proteins in a test tube and let
them incubate for 30 minutes. After the incubation, what do you find in the test tube?
a. secretory proteins floating free in the buffer in the test tube
b. secretory proteins inside RER vesicles with no ribosomes bound to them (naked vesicles)
c. secretory proteins inside RER vesicles with ribosomes bound to their outer surface
d. domestic proteins in the RER vesicles with ribosomes bound to their outer surface
e. a and c
65. Which cell junction below may attach epithelial cells to each other and seal off the space between the
cells so that nothing can pass between them?
a. tight junctions b. maculae adherens
c. zonulae occludens d. spot desmosomes
e. a and c
66. What anatomical specialization is essential for C4 photosynthesis?
a. Bundle sheath cells around vascular tissue are surrounded by mesophyll cells.
b. Two cylinders of cells surround the plant's vascular tissues: bundle sheath cells on the outside and
mesophyll cells on the inside.
c. Mesophyll cells, where Calvin cycle occurs, are scattered throughout the air spaces inside the leaves
d. a and c
e. Stomata are larger and permanently open.
67. What cell junction(s) is (are) responsible for allowing lower molecular weight materials to pass freely
between the cytoplasms of two adjacent cells?
a. gap junctions
b. a and c c. plasmodesmata d. tight junctions e. c and d
68. Which of the molecules below is an example of the type of molecule that glycosyltransferases
require to complete their reaction of adding sugars to growing oligosaccharide chains?
a. nucleoside sugars b. UDP-galactose
c. ATP
d. ADP
e. a and b
69. Which of the following activities is not triggered by the release of calcium ions?
a. secretion b. exocytosis c. lipid synthesis d. activation of a fertilized egg e. all of the above
70. In which cell junction do the membranes have a larger distance separating them than in regions of
the membrane where there are no cell junctions?
a. spot desmosomes b. maculae adherens
c. tight junctions
d. gap junctions
e. a and b
71. A pulse-chase experiment is carried out by exposing rat parotid cells to radioactive amino acid
precursors for a brief period of time followed by increasing chase periods in the presence of unlabeled
amino acid precursors. What is(are) the most important revelation(s) of this technique?
a. the time it takes to synthesize a single protein
b. the time it takes to synthesize a membrane lipid
c. the time it takes for a secretory protein to be secreted
d. the pathway membrane proteins follow through the cell on their way to the membrane
e. c and d
70. You isolate the gene for a secretory protein and remove the nucleotides that code for first 30 amino
acids on the protein's N-terminal end. You are then able to add this nucleotide sequence to the
beginning of the gene for a domestic protein. You are able to replace the normal gene for this
domestic protein in a rat cell with the altered form of the gene you have produced. When the rat cell
and its descendents start to make this protein in which of the following places is it likely to be found?
Biology 263
Dr. Joel B. Piperberg
Final Exam
Page #8
a. in the SER lumen
b. in the lysosomes
Cell Biology
May 5, 2010
Name _________________________________
c. in the cytoplasm
d. in the extracellular matrix
e. a and d
71. __________ allow molecules with low molecular weights to pass between cells via a direct
connection between their cytoplasms. The purpose of this connection is to allow communication
between the cells so that they can _________.
a. Plasmodesmata, communicate with each other c. Gap junctions, swell
e. a and d
b. Plasmodesmata, disassociate
d. Gap junctions, act in a coordinated fashion
74. What is the importance of regulating the conversion of NAD to NADP in the cell?
a. High amounts of NADP mean that the cell will shrink.
b. High amounts of NADP will lead to the cell running primarily biosynthetic reactions.
c. High amounts of NADP lead to the inhibition of catabolic reactions that produce ATP.
d. High amounts of NAD activate catabolic reactions that generate ATP.
e. b, c and d
75. A disease, which results in severe blistering of the skin, would be most likely to result from a defect in _____.
a. hemidesmosmes
c. cells' adhesion to each other
e. a and b
b. cell adhesion to the basal lamina
d. zonula occludens
76. You are observing cells that secrete proteins into a duct at their apical surface. In what order would you
encounter cell junctions if you could travel between these cells from the basal surface toward the apical surface?
a. belt desmosome, tight junction, spot desmosome
b. tight junction, spot desmosome, belt desmosome
c. spot desmosomes, belt desmosomes, tight junctions
d. tight junction, belt desmosome, spot desmosome
e. spot desmosome, gap junction, belt desmosome
77. What organelle is responsible for hydrolyzing large macromolecules?
a. lysosome b. glyoxysome c. chloroplast
d. peroxisome
e. mesosome
78. Which organelle could be viewed as a transitional organelle between the RER and the Golgi complex?
a. plasma membrane b. lysosome c. peroxisome
d. SER
e. nucleus
79. Which of the following can be found in the inner leaflet of the RER?
a. signal peptidase b. dolichol phosphate
c. ribosomes
d. peptidyl transferase
e. a and b
80. A yellow sponge is dissociated mechanically and a red sponge is dissociated chemically by placing it
in Ca+2 - Mg+2 - free sea water. Both cell suspensions are washed in natural sea water a number of
times and placed together in natural sea water at 4°C. Washes were performed by centrifuging the
dissociated sponge cells and removing the supernatant. If the supernatant from the first centrifugation
(i. e., the solution surrounding the cells during dissociation) of the yellow sponge is added to the
above mixture of red and yellow sponges, what happens?
a. Neither sponge reassociates.
d. Both sponges reassociate into one mass
b. The red sponge reassociates; the yellow sponge does not. e. Both sponges reassociate into separate masses.
c. The yellow sponge reassociates; the red sponge does not
81. What happens if the mixture of dissociated red and yellow sponges mentioned above is cultured at
4°C with the addition of supernatant from the initial centrifugation of the red sponge?
a. Both sponges eventually reassociate into one mass. d. The red sponge reassociates; the yellow does not.
b. Neither sponge reassociates.
e. Both sponges eventually reassociate independently.
c. The yellow sponge reassociates; the red does not.
Biology 263
Cell Biology
Dr. Joel B. Piperberg
May 5, 2010
Final Exam
Name _________________________________
Page #9
82. Which of the following proteins would be likely to be synthesized on RER-bound ribosomes?
a. integrins b. glycolytic enzymes c. steroid receptors d. a and e e. collagen
83. What is the name of the process that is responsible for the breakdown of the membranes surrounding
an egg resulting in its fertilization?
a. autophagy
b. autolysis
c. apoptosis
d. extracellular digestion
e. b and c
84. What process is responsible for the disappearance of the webbing between the fingers and toes of a
developing human embryo?
a. autophagy
b. programmed cell death c. apoptosis d. extracellular digestion
e. b and c
85. Which cell adhesion molecules are related structurally to antibodies of the immune system?
a. selectins
b. lectins
c. IgSFs
d. selectins
e. cadherins
86. Strauss performed an experiment in 1964. He injected the enzyme horseradish peroxidase into his
experimental organism. Some cells in the organism took up the horseradish peroxidase by endocytosis.
Eventually, the endosomes containing horseradish peroxidase met up with lysosomes and merged with
them. What color were the vesicles containing the horseradish peroxidase after they were presented with
special substrates for the horseradish peroxidase and the enzyme that serves as a marker for lysosomes
and after they fused with a lysosome?
a. yellow
b. blue
c. red
d. green
e. purple
87. You have just found a dead deep-sea creature in your fishing nets. It appears to be a new species.
During the post-mortem attempt to classify the organism, a jelly-like, extracellular mass is found in
the abdomen. It is found to contain protein and carbohydrate and lots of water. What kind of
molecule would you expect to find in the jelly-like mass?
a. proteoglycan aggregates b. glycosaminoglycans c. proteomucoids d. mucoproteins e. a, b and d
88. There are membrane proteins that bind to a specific three amino acid sequence (designated RGD) in a
number of ECM proteins. A dish is coated with a protein containing the RGD sequence. Some cultured
cells with these proteins embedded in their membranes were added to the culture dish along with
tripeptides of the RGD sequence. The cells do not bind to the dish. What is the name of these membrane
proteins?
a. integrins
c. selectins
e. a and d
b. noncompetitive inhibitors
d. competitive inhibitors
89. The fuzzy layer is composed of ____________.
a. carbohydrates attached by covalent bonds to membrane proteins
b. carbohydrates attached by weak interactions to integral membrane glycoproteins
c. the cell coat and the glycocalyx
d. a and c
e. a, b and c
Biology 263
Dr. Joel B. Piperberg
Final Exam
Page #10
Cell Biology
May 5, 2010
Name _________________________________
H
CH
2
CH
2
CH
2
N
C
NH
CH
2
NH
arginine
CH 3
CH
2
CH
leucine
CH
O
CH
2
C
O
HO
CH
OH
aspartate
tyrosine
CH
3
CH
valine CH
CH SH
2
cysteine
CH CH S CH
2
methionine
alanine
O
CH
2
CH
2
glutamine
2
NH2
2
CH
CH OH
2
serine
C
2
OH
glutamate
O
CH
2
CH
2
CH
2
CH
3
H
CH 3
OH threonine
2
NH
lysine
H
C
C
CH
2
3
CH 3
H
glycine
2
phenylalanine
3
2
C
CH 2 CH 3
CH3 isoleucine
CH
CH
2
2
CH
CH
C
2
NH2
asparagine
CH
2
histidine
N proline
H
NH
+
C
H
2
HC
CH
C
HN
CH
tryptophan
2
C
HC
N
H
III. Lecture Short Answer
1. Name two things to which the SRP binds. Name a class of macromolecules that is not a part of the
SRP's structure. (3 points)
2. What pathway do phospholipids follow on their way from synthesis to the cell surface? (2 points)
3. You have fractionated a plant cell into a cytoplasmic portion, a nuclear portion, a fraction composed
of the inner mitochondrial membranes, a fraction composed of the outer mitochondrial membranes, a
fraction composed of thylakoid membranes, a fraction containing the chloroplast stroma and a
fraction containing the mitochondrial matrix. Where would you expect to find the:
a. the enzymes responsible for fermentation?
b. lollipop structures?
c. electron transport chain for the light-dependent reactions?
d. NADre molecules released by the Krebs cycle?
e. the enzyme responsible for adding phosphate groups to glucose during aerobic respiration?
f. ribulose bisphosphate carboxylase
(6 points)
BONUS QUESTIONS
1. Describe the flow of electrons during cyclic photophosphorylation from the place where they
originate to where they eventually end up? What drives their movement? (3 points)
Biology 263
Cell Biology
Dr. Joel B. Piperberg
May 5, 2010
Final Exam
Name _________________________________
Page #11
2. What do plants produce when they operate anaerobically? (2 points)
3. When animal cells operate anaerobically, what do they generally produce? (1 point)
4. Non-cyclic photophosphorylation normally results in the production of _______ and _______. (2 points)
5. The following statements apply to photosynthesis, cellular respiration, both processes or neither
process. Indicate which process is referred to in each statement by writing either P, C, PC or N in the
blank before each statement. (16 points)
_______ a. Uses oxygen as a reactant
_______ b. ATP is produced by adding to ADP a phosphate group that has been transferred from
another phosphorylated substrate (substrate-level phosphorylation)
_______ c. The whole process occurs in the mitochondria
_______ d. Generates chemical intermediates useful in other cellular pathways
_______ e. Makes use of the Hill reaction
_______ f. Oxidized coenzymes are reduced during the process
_______ g. Carbon dioxide is an overall product of this process
_______ h. During this process, a six-carbon molecule breaks into two 3-carbon fragments
_______ i. Some of the reactions involved occur in a milieu that may be called the matrix
_______ j. At least part of the process can occur in the absence of light
_______ k. GTP is produced during the process
_______ l. Produces NADre at some point in the process.
_______ m. Water is used up during this process
_______ n. FADPre is used during the process
_______ o. Developed first evolutionarily
_______ p. This process occurs in plants
6. What molecule and relative of ATP carries carbons that originate in pyruvate into the Krebs cycle. (1 point)
7. What is another name for apoptosis? (1 point)
8. To what does CO2 initially add during C4 photosynthesis when it is being fixed out of the
atmosphere? (1 point)
9. Who was the first woman nominated for the Vice Presidency by a major political party? (1 point)
10. Who plays Professor Xavier in the X-Men movies? What role did the actor who played Magneto in
the X-men movies play in The Lord of the Rings trilogy? (2 points)
11. Who was living in the White House when the British burned it during the War of 1812? (1 point)
Biology 263
Dr. Joel B. Piperberg
Final Exam
Page #12
Cell Biology
May 5, 2010
Name _________________________________
12. What is wrong with the following list of molecules? (1 point)
UDP-glucose, UDP-galactose, CMP-sialic acid, CMP-glucuronic acid, CMP-glucose
13. Which compartment in mitochondria is likely to have the lowest pH? Which compartment in
chloroplasts is likely to have the lowest pH? (2 points)
14. What is responsible for moving dolichol phosphate from the cytoplasmic leaflet of the RER to the
luminal leaflet of the RER? (1 point)
15. How does a poison like cyanide kill a person? (1 point)
16. How does a plant manage to avoid a decrease in pH during the light-independent reactions when H+
ions are released when water molecules are split during the Hill reaction? (1 point)
17. What kind of plants evolved to do well in dry arid climates like the middle of July in Pennsylvania?
What is an example of such a plant? (2 points)
18. What kind of plants evolved to conserve water while running photosynthesis in the desert? What is
an example of such a plant? (2 points)
19. Three tissues (A, B and C) from a vertebrate embryo are dissociated and then allowed to reassociate
in pairs. If in these aggregates, Tissue A ends up external to Tissue C and Tissue B ends up internal
to Tissue C. What happens if Tissue A and Tissue B are mixed together? (1 point)
20. What is the name of the protein domain that binds to the phosphorylated tyrosine of an activated
insulin receptor? (1 point)
21. What is the name of a molecule that is phosphorylated by an RTK? (1 point)
22. The process of protein production is broken up into two parts. Name and define them. (2 points)
23. What lysosomally controlled cell process is exemplified by:
a. the abnormal secretion of enzymes that damage the lining of joints
Biology 263
Dr. Joel B. Piperberg
Final Exam
Page #13
Cell Biology
May 5, 2010
Name _________________________________
b. digestion of an invading microorganism by a macrophage
c. the removal of the webbing between the fingers and toes of a developing human embryo
d. recycling of the components of cellular organelles
(4 points)
24. Which phase of mitosis or meiosis is defined by the following descriptions? Specify the phase and
whether you are talking about mitosis, meiosis I, or meiosis II. (6 points)
a. A diploid number of chromosomes is lined up in the center of the cell; each chromosome consists
of 2 chromatids.
b. A haploid number of chromosomes splits at the centromere and begins moving to the opposite poles
of the cell.
c. A haploid number of chromosomes decondenses and becomes sequestered in the newly formed
nuclei of 2 daughter cells; each chromosome consists of 2 chromatids.
d. A diploid number of chromosomes condenses and each can be seen to consist of two chromatids;
they are paired and the nuclear membrane begins to disintegrate.
e. A diploid number of paired chromosomes lines up in the center of the cell.
f. A haploid number of chromosomes moves to the opposite poles of the cell; each chromosome has 2
chromatids.
25. What type of signaling is typified by a single receptor influencing multiple effectors? (1 point)
26. An organism has a diploid number of 72. How many total chromosomes are in 18 of its egg cells? (1 point)
27. An organism has a haploid number of 24. How many total chromosomes are there in 21 skin cells
from this organism? (1 point)
28. You are working with a gene in human cells. After cloning and sequencing it, you discover that there is
a very similar gene in yeast cells. If you take a normal version of the yeast gene and introduce it into a
human cell that possesses a mutant version of the corresponding gene, what is likely to happen? (1 point)
Biology 263
Dr. Joel B. Piperberg
Final Exam
Page #14
Cell Biology
May 5, 2010
Name _________________________________
Have a good summer. Come back safe in the Fall.
Course Survey (2 points)
1. The thing I liked most about this course was
2. The thing I liked least about this course was
3. If I could change one thing about this course, it would be
4. The lab I liked most was
5. The lab I liked least was
6. What topic that was not discussed would you most like to hear about?
7. General comments
Biology 263
Dr. Joel B. Piperberg
Final Exam
Page #15
Cell Biology
May 5, 2010
Name _________________________________