Cell Bio Exam 3: Chapter 7, Chapter 8
Glycolipids
cerebrosides
sterols
cholesterol
17) The chloride-bicarbonate antiport is thought to function by which of the following mechanisms? A) "ping-pong" B) "ying-yang" C) uniport dichotomy D) active transport E) induced-fit model
A) "ping-pong"
19) What is the ∆G′ for the inward transport of sucrose? A) +1.774 kcal/mol; an endergonic reaction B) +1.774 kcal/mol; an exergonic reaction C) -1.774 kcal/mol; an endergonic reaction D) -1.774 kcal/mol; an exergonic reaction E) none of the above
A) +1.774 kcal/mol; an endergonic reaction
29) Which type of ATPase is associated with the integral binding of ATP as part of the transport process? A) ABC type B) F type C) P type D) V type
A) ABC type
18) Facilitated diffusion implies that energy in which form is NOT required? A) ATP B) oxygen C) Na D) glucose E) light
A) ATP
25) Cystic fibrosis is the result of a malfunction of the cell in transporting which of the following ions? A) Cl- B) K C) Na D) glucose E) OH-
A) Cl-
2) One mechanism by which ions are specifically transported into the cell is the A) gated channel. B) alternating conformation model. C) carrier protein transport. D) uniport transport model. E) all of the above
A) Gated channel
8) You are examining an electron micrograph of cells obtained from a new deep-sea life form. Upon closer examination, you notice that there are two dark lines separated by a lightly stained region. These results are similar to the observation of which investigator(s) of membrane structure? A) Robertson B) Gorter and Grendel C) Unwin and Henderson D) Overton E) Singer and Nicolson
A) Robertson
29) The technique that allows various proteins to be differentiated based on size, once the proteins have been denatured, is A) SDS-PAGE. B) photobleaching. C) liposome formation. D) ferritin-conjugated lectins. E) the freeze-fracture technique.
A) SDS-PAGE.
36) The graph below shows the rate of transport for each substance when the cells are placed in 0.10 mM solutions of A, B, and C. Based on these data and coupled with the data observed above, substance C is transported via ________ A) active transport B) facilitated transport C) passive transport D) simple diffusion E) choices A, B, and C
A) active transport
5) In the kidney, the specialized transport proteins that allow for very rapid fluid movement into or out of cells are known as A) aquaporins. B) porins. C) ionophores. D) anion exchange proteins. E) osmosins.
A) aquaporins
38) Membranes contain several classes of lipids, such as phospholipids, sphingolipids, sterols, etc. In spite of their many differences, they all A) are soluble in nonpolar solvents. B) can be easily hydrolyzed. C) are readily soluble in water at 37C. D) can be reduced by strong reducing agents such as sodium. E) easily react with bases but not with acids.
A) are soluble in nonpolar solvents.
10) With respect to the outer and inner faces of the lipid bilayer of the cell membrane, the composition of lipids is A) asymmetrical. B) identical. C) not identical but symmetrical. D) highly random and varies throughout the cell. E) a mirror image.
A) asymmetrical.
31) With respect to the outer and inner faces of the lipid bilayer of the cell membrane, the composition of proteins is A) asymmetrical. B) identical. C) not identical but symmetrical. D) highly random and varies throughout the cell. E) a mirror image.
A) asymmetrical.
38) Animal cells use exocytosis to secrete all of the following except A) cell wall material. B) mucus. C) peptide hormones. D) milk proteins. E) digestive enzymes.
A) cell wall material.
14) Of the following lipids, which is found in approximately equal amounts in both the outer and inner portions of the lipid bilayer? A) cholesterol B) glycolipid C) phosphatidylserine D) phophatidylethanolamine E) phophatidylinositol
A) cholesterol
1) requires a specific integral membrane protein
A) diffusion and passive and active transport
4) Keq = 1
A) diffusion and passive and active transport
9) ΔG° = 0
A) diffusion and passive and active transport
18) Where would you expect to find an organism possessing a cell membrane composed of large proportions of cholesterol and a predominance of unsaturated fatty acids? A) frozen wastelands B) temperate regions C) tropical regions D) equatorial regions E) upper levels of an aquatic environment
A) frozen wastelands
20) The ability of some organisms to compensate for temperature changes by altering the lipid composition of membrane lipids is known as A) homeoviscous adaptation. B) ectothermic adaptation. C) kleptothermic adaptation. D) A and B only E) none of the above
A) homeoviscous adaptation.
9) Which of the following is/are true with regard to water movement in osmosis? A) hypotonic → hypertonic B) hypertonic → hypotonic C) isotonic → hypotonic D) hypertonic → isotonic E) both choices C and D
A) hypotonic → hypertonic
19) A prokaryotic organism is isolated from a hydrothermal vent, where it has been observed to be thriving. Based on your knowledge of the plasma membrane, you would expect to find a predominance of A) largely saturated fatty acids. B) equal amounts of saturated and unsaturated fatty acids, as long as the chain was close to 12 carbons in length. C) polar fatty acids. D) largely unsaturated fatty acids. E) none of the above
A) largely saturated fatty acids.
40) A special class of ABC-type ATPases associated with tumors that allow movement of antibiotics and other drugs out of the cell are known as A) multidrug resistance transport protein. B) import transporter proteins. C) cystic fibrosis transmembrane conductance regulator. D) human catalytic convertase. E) none of the above; no such transporter has been identified in eukaryotes.
A) multidrug resistance transport protein.
8) Which of the following measures is used to determine a substance's polarity? A) partition coefficient B) extinction coefficient C) polarity factor D) asymmetrical distribution points E) polarity determining factor
A) partition coefficient
11) Based on the composition of cell membranes, the most prominent lipids are A) phospholipids. B) glycolipids. C) cholesterol. D) phytosterol. E) cerebrosides.
A) phospholipids.
36) Cell-cell communication in plants takes place via specialized structures called A) plasmodesmata. B) desmids. C) gap junctions. D) cell wall pores. E) connexons.
A) plasmodesmata.
30) The P-type ATPases associated with the movement of heavy metals are A) type 1. B) type 2. C) type 3. D) type 4. E) type 5.
A) type 1
8) ________ is the name given to the technique that utilizes radioactive molecules that bind to specific membrane proteins.
Answer: Affinity labeling
14) ________ are small peptide molecules (10—50 amino acids in length) that affect membrane permeability.
Answer: Antimicrobial peptides, or AMPs
10) ________ is a sterol associated with fungal cell membranes.
Answer: Ergosterol
6) The type of transport ATPase found in bacteria, mitochondria, and chloroplasts are the ________ ATPases.
Answer: F-type
7) The type of transport ATPase that are reversibly phosphorylated as part of the transport mechanism are the ________ ATPases.
Answer: P-type
4) ________ are organisms that are unable to regulate their body temperature.
Answer: Poikilotherms
9) ________ is the name of the technique used for the analysis of membrane lipids.
Answer: Thin-layer chromatography
1) Transmembrane movement of a substance against a concentration gradient is called ________.
Answer: active transport
5) The transport of two molecules across the cell membrane in different directions is called ________.
Answer: antiport
11) Most unsaturated fatty acids are in the ________ configuration, but some are in the ________ configuration, making their shape more like that of saturated fatty acids.
Answer: cis; trans
10) Receptor-mediated endocytosis involves vesicles with a special coat protein known as ________.
Answer: clathrin
1) In E. coli the enzyme responsible for creating unsaturated bonds from saturated ones in the fatty acids of the cell membrane is ________.
Answer: desaturase
3) Transmembrane movement of a substance with a concentration gradient, with no involvement of membrane proteins, is called ________.
Answer: diffusion
8) Uptake of food particles by trapping them within an invagination of the plasma membrane is called ________.
Answer: endocytosis
6) The current understanding of the membranes of the cell is based on the ________ model.
Answer: fluid mosaic
7) The ability of some organisms to alter their membrane lipid composition in response to temperature is known as ________.
Answer: homeoviscous adaptation
2) Substances that can readily pass through the cell membrane are chemically ________ in nature.
Answer: hydrophobic or nonpolar
9) A(n) ________ solution is one that contains a solute concentration that is ________ than that within the cell and results in the "bursting" of the cell.
Answer: hypotonic, lower
12) The presence of trans fats in membranes ________ the transition temperature and ________ membrane fluidity.
Answer: increases; decreases
11) In the capillaries of the body tissues, CO2 diffuses ________ and is converted to ________.
Answer: inward; bicarbonate
12) In the capillaries of the lungs, O2 diffuses ________ and is bound to ________.
Answer: inward; hemoglobin
2) Transmembrane movement of a substance with a concentration gradient utilizing a membrane protein is called ________.
Answer: passive transport or facilitated transport
3) The shifting of membrane fluidity from a gel-like to a more liquid state is known as ________.
Answer: phase transition
13) Pores of the outer membrane of bacteria, mitochondria, and chloroplasts that are less specific and are formed by multipass transmembrane proteins are called ________.
Answer: porins
5) Transmembrane proteins involved in detecting external stimuli and relaying that information to the cell are most likely ________ proteins.
Answer: receptor
4) The transport of two molecules across the cell membrane in the same direction is called ________.
Answer: symport
13) The technique of transferring proteins from SDS-PAGE gels onto a membrane and using labeled antibodies to identify particular proteins is known as a(n) ________.
Answer: western blot
23) Assuming no change in either the internal or external calcium ion concentration, at what membrane potential would there be no net movement of calcium across the membrane? A) -25 mV B) -50 mV C) 0 mV D) 25 mV E) 50 mV
B) -50 mV
13) Which of the following glucose transporters in humans has properties that facilitate glucose transport out of the cell in response to keeping blood sugar levels homeostatic? A) GLUT1 B) GLUT2 C) GLUT3 D) GLUT4 E) GLUT5
B) GLUT2
23) Hopanoids A) are found in eukaryotes only. B) are related to cholesterol. C) are a type of glycolipid. D) are a type of phospholipid. E) all of the above
B) are related to cholesterol.
11) requires ligand binding and therefore Michaelis constants can be calculated
B) both passive and active transport
26) To facilitate the regulation of membrane fluidity, E. coli has the enzyme A) bacteriorhodopsin. B) desaturase. C) fatty acid convertase. D) gangliosidase. E) unsaturase.
B) desaturase.
27) Which of the following is not a characteristic of active transport? A) sensitive to metabolic poisons B) exclusively move one molecule at a time in a unidirectional manner C) can be coupled with passive transport to generate the energy necessary for active transport D) can work as symports or antiports E) all of the above
B) exclusively move one molecule at a time in a unidirectional manner
5) Which of the following molecules would not readily cross an intact cell membrane by simple diffusion? A) water B) glucose C) oxygen D) fatty acids E) ethanol
B) glucose
4) In bacteria, the porins have the unique ability to transport A) all hydrophilic molecules. B) hydrophilic molecules of a particular size. C) all hydrophobic molecules. D) hydrophobic molecules of a particular size. E) any molecule, regardless of properties or size.
B) hydrophilic molecules of a particular size
17) Cholesterol A) is found in abundance in prokaryotic cell membranes. B) intercalates between the fatty acid chains within the bilayer. C) increases permeability for small cations. D) destabilizes the cell membrane. E) is found only in plants.
B) intercalates between the fatty acid chains within the bilayer.
40) The venom of black widow spiders (Latrodectus mactans) contains an enzyme that hydrolyzes lecithin to the phospholipid lysolecithin. The lysolecithin lyses red blood cells, destroying them. One possible mechanism whereby lysolecithin disrupts the plasma membranes of red blood cells is that it A) is toxic to red blood cells. B) may act in a manner similar to detergents. C) binds calcium ions, compromising membrane integrity. D) acts as a second messenger to stimulate apoptosis. E) None of the above is a possible mechanism.
B) may act in a manner similar to detergents.
15) When transporting charged molecules across a membrane, which of the following is/are true? A) When moving chloride ions in nerve cells, the movement is with both concentration and electrochemical gradients. B) ΔG is dependent on electrochemical potential. C) Keq is always equal to zero. D) ΔG° is always equal to one. E) Membrane potential is not a factor.
B) ΔG is dependent on electrochemical potential.
14) When transporting uncharged molecules across the membrane, which of the following is/are false? A) Keq is always equal to one. B) ΔG is not dependent upon a gradient. C) Movement requires a transport protein. D) ΔG° is always equal to zero. E) both choices A and B
B) ΔG is not dependent upon a gradient
24) The most common number of carbons in fatty acid hydrocarbon chains of membrane phospholipids is A) 7. B) 10. C) 16. D) 19. E) 24.
C) 16.
37) The primary difference between active transport and facilitated diffusion is that active transport is the only one in which A) [S]high → [S]low. B) transporter proteins are required. C) [S]low → [S]high. D) the concentration gradient provides the necessary energy for movement. E) only water molecules move.
C) [S]low → [S]high.
12) Which of the following organisms would contain sphingomyelin in its cell membrane? A) bacteria B) algae C) animals D) bryophytes E) angiosperms
C) animals
39) Mutations in bacterial porins can lead to antibiotic resistance typically by A) closing the α-helix of the porin. B) limiting the passage of nonpolar substances. C) blocking entry of the antibiotic. D) disrupting the voltage of the gated channel. E) all of the above
C) blocking entry of the antibiotic.
2) dependent on solubility properties of the solute
C) diffusion
7) exclusively involves the transfer of small, nonpolar molecules
C) diffusion
1) Which of the following is not a function of membranes? A) define cell boundaries B) compartmentalization C) information storage D) regulation of transport E) cell-cell communication
C) information storage
16) Based on your knowledge of the chemistry of the cell membrane, which of the following compounds would you couple with a new drug in order to achieve better uptake by cells? A) carbohydrates B) polar amino acids C) lipids D) several mannose-6-phosphate monomers E) any hydrophilic substance
C) lipids
13) Of the following lipids, which would you expect to find associated with chloroplast membranes? A) phosphatidylserine B) glycosphingolipid C) monogalactosyldiacylglycerol D) galactocerebroside E) hopanoids
C) monogalactosyldiacylglycerol
3) Temperature has a dramatic effect upon cell membranes. This influence can readily make a cell membrane more solid or more fluid in response to the temperature. This is an example of A) liquidation. B) membrane flexibility. C) phase transition. D) membrane asymmetry. E) scanning calorimetry.
C) phase transition
21) Inactivation of a fluorescent dye in a very concentrated spot on a cell so that the fluidity of membranes can be visualized is called A) liposome formation. B) SDS-PAGE. C) photobleaching. D) the freeze-fracture technique. E) ferritin-conjugated lectins.
C) photobleaching.
28) Which of the following is not a mechanism of active transport? A) coupled transport B) ATP hydrolysis-driven pump C) unidirectional movement with gradients D) light-driven pumps E) both choices C and D
C) unidirectional movement with gradients
7) With regard to the semipermeable nature of the plasma membrane, which of the following would readily cross without the aid of a transport protein? A) calcium ions B) glucose C) water D) amino acids E) DNA
C) water
D) described the chemical nature of the cell membrane
Charles Overton
21) What would be the net ∆G′ for the coupling of these two reactions? A) 7.007 kcal/mol B) 3.459 kcal/mol C) -1.774 kcal/mol D) -3.459 kcal/mol E) -7.007 kcal/mol
D) -3.459 kcal/mol
22) What is the free energy change for the inward movement of calcium ions into the bacterial cell? A) 4.6 kcal/mol; an endergonic reaction B) 4.6 kcal/mol; an exergonic reaction C) -4.6 kcal/mol; an endergonic reaction D) -4.6 kcal/mol; an exergonic reaction E) none of the above
D) -4.6 kcal/mol; an exergonic reaction
20) What is the ∆G′ for the inward transport of sodium ions? A) +5.233 kcal/mol; an endergonic reaction B) +5.233 kcal/mol; an exergonic reaction C) -5.233 kcal/mol; an endergonic reaction D) -5.233 kcal/mol; an exergonic reaction E) none of the above
D) -5.233 kcal/mol; an exergonic reaction
32) The Na/K pump actively moves A) 2 Na in, 3 K out. B) 2 Na out, 3 K in. C) 3 Na in 2 K out. D) 3 Na out, 2 K in. E) 1 Na out, 1 K in.
D) 3 Na out, 2 K in.
9) The scientist(s) who developed the "sandwich" model of the cell membrane is (are) A) Overton. B) Langmuir. C) Gorter and Grendel. D) Davson and Danielli. E) Robertson.
D) Davson and Danielli.
1) Of the following molecules, which would not be expected to be moved across a membrane by simple diffusion? A) oxygen B) fatty acids C) water D) glucose E) dimethylurea
D) Glucose
22) You are experimenting with a variety of lipids to determine their efficacy for use as drug delivery system liposomes. What is one feature of the individual lipid that would best ensure the use of a lipid for this purpose? A) It must have a structure similar to cholesterol. B) It must be composed entirely of unsaturated fatty acids. C) It should be exclusively hydrophilic. D) It should be amphipathic. E) It should be exclusively hydrophobic.
D) It should be amphipathic.
33) An example of indirect active transport is A) Na/K pumps. B) P-type ATPases. C) ABC-type ATPases. D) Na/glucose symport. E) both choices B and C
D) Na/glucose symport.
12) Which of the following is not a characteristic of passive transport? A) It requires binding of the molecule to be transported. B) It is specific for the molecule being transported. C) The energy for transport is generated by the gradient of the substance being transported. D) The energy for transport is generated by the molecular bonds of the substance being transported. E) Transport of the substance is the result of a conformational change.
D) The energy for transport is generated by the molecular bonds of the substance being transported.
4) Two cells with different cell-surface markers are fused in the presence of polyethylene glycol (PEG). The cells are then placed at 0°C. What do you expect to observe about the individual cell markers? A) The markers will evenly disperse throughout both membranes. B) Only one marker will disperse, while the other remains stationary. C) Both sets of markers will not mix but will migrate to opposite poles from one another. D) The markers will essentially remain where they are, with little migration. E) The markers will be endocytosed by the fused cell and then redistributed as fused markers.
D) The markers will essentially remain where they are, with little migration.
3) requires cellular expenditure of energy
D) active transport
6) Na+/K+ pump
D) active transport
6) In all organisms, active transport across a membrane requires A) equal concentrations of ions on both sides of the membrane. B) a resting potential of 0 mV. C) exergonic movement indicated by the direction of the electrochemical potential. D) an asymmetric distribution of ions across a membrane. E) both choices B and D
D) an asymmetric distribution of ions across a membrane
32) A colleague gives you two membrane fractions from a plant cell lysate. One contains the plasma membrane fraction, the other the mitochondrial fraction. The tubes are not labeled, but you run the samples anyway, looking at the macromolecule composition of the samples. You know for certain that the second sample contains the mitochondrial fraction simply because it contains insignificant amounts of A) lipids. B) protein. C) specifically phospholipids. D) carbohydrates. E) both choices C and D
D) carbohydrates.
33) A means of detecting the presence of specific carbohydrate moieties on glycoproteins is A) SDS-PAGE. B) the freeze-fracture technique. C) photobleaching. D) ferritin-conjugated lectins. E) liposome formation.
D) ferritin-conjugated lectins.
37) The likely number of and locations of transmembrane segments of integral membrane proteins is inferred by A) X-ray crystallography. B) SDS-PAGE. C) western blot. D) hydropathic analysis. E) affinity labeling.
D) hydropathic analysis
35) Many integral membrane proteins have not been analyzed by X-ray crystallography. However, transmembrane segments can be inferred using computer analysis of the amino acid sequence of the protein. This technique is known as A) homeoviscous adaptation. B) lipid analysis. C) lipid rafting. D) hydropathic analysis. E) SDS-PAGE.
D) hydropathic analysis.
39) Naturally occurring fatty acids are typically A) saturated. B) unsaturated. C) in the trans configuration. D) in the cis configuration. E) comprised of an odd number of carbon atoms.
D) in the cis configuration.
15) A prokaryotic organism is isolated from a glacier, where it was thriving. Based on your knowledge of the plasma membrane, you would expect to find a predominance of A) largely saturated fatty acids. B) equal amounts of saturated and unsaturated fatty acids, as long as the chain was close to 12 carbons in length. C) cell wall to define the cell because the cell membrane would not be present. D) largely unsaturated fatty acids. E) none of the above
D) largely unsaturated fatty acids.
34) Localized regions of membrane lipids that contain proteins involved in cell signaling are known as A) hopanoids. B) membrane leaflets. C) homeoviscous adaptations. D) lipid rafts. E) islands of hydropathy.
D) lipid rafts.
7) The movement of water through a membrane, from an area of high concentration to an area of low concentration, is known as A) active transport. B) facilitated transport. C) passive transport. D) osmosis. E) photolysis.
D) osmosis
34) The graph above shows the initial rate of transport for each substance when the cells are placed in solutions of different concentrations of A, B, and C. Based on these data, substance A is transported via A) active transport. B) facilitated transport. C) passive transport. D) simple diffusion. E) choices A, B, and C
D) simple diffusion.
31) While working with a novel cell line, you observe that movement of hydrophobic molecules, such as cholesterol and fatty acids, is impaired. You narrow the defect down to a P-type ATPase A) type 1. B) type 2. C) type 3. D) type 4. E) type 5.
D) type 4
F) proposed the "lipid protein sandwich" model of the cell membrane
Davson and Danielli
11) You wish to dehydrate a piece of meat using solutions of varying salt concentrations. The best concentration to use would be A) 0.01%. B) 0.09%. C) 0.9%. D) 1%. E) 10%.
E) 10%.
28) Which of the following disorders is the result of impaired glycosphingolipid metabolism? A) leprosy B) glycosphingolipid anemia C) polydactyly D) tuberculosis E) Tay-Sachs disease
E) Tay-Sachs disease
2) Which is not a model for membrane structure? A) Overton lipid coat B) Langmuir monolayer C) Gorter and Grendel bilayer D) Singer and Nicholson fluid mosaic E) Watson and Crick double helix
E) Watson and Crick double helix
27) Lipid rafts have been associated with which of the following? A) responses to extracellular signals B) transport of nutrients across cell membranes C) immune responses D) transport of cholera toxin into cells E) all of the above
E) all of the above
3) In examining glucose transport into a cell, the immediate phosphorylation of glucose following its entry into the cell A) keeps the glucose from being transported back out of the cell. B) allows the cell to maintain higher levels of glucose outside the cell. C) converts glucose into a form for use in cellular respiration. D) converts glucose into a form to be stored. E) all of the above
E) all of the above
35) Based on the same graph, substances B and C A) show saturation kinetics. B) are transported by a transporter protein. C) do not move by simple diffusion. D) choices A and B only E) all of the above
E) all of the above
26) In some cells, it was noted that water moved faster than could be accounted for by simple diffusion. From this information, which of the following were identified and characterized? A) hydroporins B) glycoporins C) facilitator porins D) lipoporins E) aquaporins
E) aquaporins
6) Which of the following molecules would enter the cell via a specialized transmembrane receptor? A) water B) fatty acids C) cholesterol D) ethanol E) gases
E) gases
25) Which of the following is a sterol-like lipid associated with the cell membrane of prokaryotes? A) stearate B) phytosterol C) linoleate D) palmitate E) hopanoids
E) hopanoids
10) You are wanting to modify plant cells. With the procedure you are using, the plant cells must be in a plasmolyzed state. This means that the plant cells must be placed in a(n) A) acid solution. B) hypotonic solution. C) isotonic solution. D) basic solution. E) hypertonic solution.
E) hypertonic solution
24) The bacteriorhodopsin proton pump creates a proton gradient that is needed in the process of anoxygenic photosynthesis. The energy necessary to drive this pump is generated by A) the rhodopsin pigment directly. B) the proton gradient itself. C) GTP hydrolysis. D) ATP hydrolysis. E) light energy.
E) light energy.
8) applies only to ions
E) none of the listed processes
16) Which of the following is not an example of facilitated diffusion? A) GLUT1 glucose transporter B) anion exchange protein C) aquaporins D) channel proteins E) oxygen transport
E) oxygen transport
30) Starting with shredded spinach leaves, you follow a procedure that allows for separation of cellular organelles. You are specifically looking for the fraction that contains the mitochondria. To identify this fraction, you should test for the A) phospholipids unique to intracellular membranes. B) general presence of enzymes that fix carbon. C) phospholipids unique to the mitochondrial membrane. D) polysaccharides that specifically surround the mitochondria. E) presence of enzymes associated with cellular respiration.
E) presence of enzymes associated with cellular respiration.
10) direction of transport is dependent upon the concentration gradient at any given point in time
F) both diffusion and passive transport
5) Na+/glucose symport
G) indirect active transport
E) demonstrated that membranes were a bilayer
Gorter and Grendel
C) was able to solubilize and create lipid monolayers
Irving Langmuir
H) used electron microscopy for the basis of the proposed "unit membrane" model
J David Robertson
Phospholipids
Phosphoglycerides
G) proposed the fluid mosaic model of the cell membrane
Singer and Nicolson
B) demonstrated transmembrane proteins
Unwin and Henderson
