* To whom proofs should be sent in the Department of Chemistry

Size: px
Start display at page:

Download "* To whom proofs should be sent in the Department of Chemistry"

Transcription

1 THE JOURNAL OF BroLmrcAL CHEMSTRV Vol No. 15. ssue of August 10, pp , 1980 Printed m U.S.A. The Mechanism of Activation of Lecithin:Cholesterol Acyltransferase by Apolipoprotein A- and an Amphiphilic Peptide* (Received for publication, December 18, 1979, and in revised form, May 2, 1980) Shinji Yokoyama, Daikichi Fukushima, Josh P. Kupferberg, Ferenc J. Kezdy, and Emil Thomas Kaiser$. From the Departments of Biochemistry and Chemistry, The Uniuersity of Chicago, Chicago, llinois A synthetic docosapeptide designed to have the optimal amphiphilic a-helical potential was shown to bind with a simple Langmuir isotherm to the surfaces of egg lecithin and cholesterol-lecithin mixed unilamellar vesicles. t is also able to activate 1ecithin:cholesterol acyltransferase when the substrate is either type of vesicle. These characteristics were compared to those of apolipoprotein A- (apo A-). The peptide and apo A- bind to egg lecithin vesicles without changing the hydrodynamic properties of the latter. We found a dissociation constant & = 1.92 X lo- M and the binding capacity N = 1.51 x lo- peptides/lecithin for the peptide and Kd = 9.0 X lo M and N = 1.74 X lo- proteins/lecithin for apo A-. By incorporating one cholesterol per four phospholipids into egg lecithin vesicles, the binding still obeyed a Langmuir isotherm. Kd values were 2.80 x O- M for the peptide and 3.0 X lo- M for apo A-, while Nincreased to 2.72 X lo- peptides/lecithin or to 3.7 X lo- proteins/lecithin. The reactions of the lecithin:cholesterol acyltransferase were activated both by apo A- and the peptide. The maximum reaction rates achieved by the peptide were 18% of that by apo A- for cholesterol esterification and 50% for fatty acid release from the lecithin of mixed vesicles, and 37% for the hydrolysis of lecithin vesicles without cholesterol. The rates of the enzyme reaction were linear functions of the concentration of either apo A- or peptide bound to the vesicles. These results show that the binding of amphiphilic peptides to the phospholipid surface is sufficient and presumably necessary for enabling the phospholipid to react with 1ecithin:cholesterol acyltransferase. Apolipoprotein A- (apo A-) is the major lipoprotein present in human plasma high density lipoprotein-3. An analysis of the structure of high density lipoprotein suggested that apolipoproteins fii the free space between the phospholipid head groups in a monolayer on the surface of the lipoprotein particle. Surface filling analysis showed that free space is created by the curvature of the surface among the poiar head groups of the phospholipids, and by the presence of cholesterol, allowing the protein to bind and cover it (1, 2). Fitch has suggested that apo A- contains six highly ho- mologous 22 amino acid segments, each of which has a high helix-forming potential (3). n the a-helical conformation, the hydrophobic and hydrophilic groups are segregated on the opposite sides of the cylindrical structure (4). Since apo A- has unusually high surface activity at the air-water interface (5) and its amphiphilic helical segments may be responsible for this property, a highly amphiphilic cy-helical docosapeptide was designed and tested as a model for apo A- (6) (Fig. 1). The sequence of this docosapeptide was constructed to be as different as possible from any segments of apo A-. The amphiphilic peptide was found to behave very similarly to apo A- at the air-water interface and in binding to egg lecithin unilamellar vesicles (6). A very important biological function of apo A-1 appears to be the activation of the enzyme lecithin: cholesterol acyltransferase (EC ) (7), and we have now investigated whether the synthetic docosapeptide displaying the surface properties of apo A- would also imitate apo A- in activating 1ecithin:cholesterol acyltransferase. The peptide also provided us with an excellent experimental tool to specify further the role of cholesterol in the binding of proteins and peptides to phospholipid surfaces. n the present paper, we describe the synthesis, purification, and some of the solution properties of the amphiphilic peptide. Also, we present the further characterization of its binding, particularly to phospholipid-cholesterol unilamellar vesicles and its effect on the 1ecithin:cholesterol acyltransferase reaction as related to its binding to the mixed vesicles. EXPERMENTAL PROCEDURES The experimental procedures including the synthesis, purification, and characterization of the amphiphilic peptide are reported in the miniprint supplement that immediately follows this paper. RESULTS Before the study of 1ecithin:cholesterol acyltransferase activation could be undertaken, the binding of apo A- and the synthetic peptide to lecithin vesicles and mixed lecithin-cholesterol vesicles had to be characterized. The binding of the peptide to vesicles was quantitated by rapid ultrafitration and that of apo A- by gel permeation chromatography. Gel permeation chromatography using Sepharose CLdB showed that K,, of the vesicles remained unchanged upon binding of apo A- and the peptide to the vesicles. The isolation and * This work was supported by United States Public Health Service Program Project HL and by United States Public Health Service HL (SCOR). The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked aduertisement in accordance with 18 U.S.C. Section 1734 solely to indicate this fact. * To whom proofs should be sent in the Department of Chemistry at the University of Chicago, The abbreviation used is: apo A-, apolipoprotein A Portions of this paper (including Experimental Procedures, Tables and 11, and Figs. 1 and 2) are presented in miniprint at the end of this paper. Miniprint is easily read with the aid of a standard magnifying glass. Full size photocopies are available from the Journal of Biologicd Chemistry, 9650 Rockvile Pike, Bethesda, Md Request Document No. 79M-2543, cite author(& and include a check or money order for $1.65 per set of photocopies. Full sized photocopies are also included in the microfilm edition of the Journal that is available from Waverly Press.

2 7334 Peptide Activator of Lecithin:Cholesterol Acyltransferase Pro-Lys-Leu-Glu-Glu-Leu-Lys-Glu-Lys-Leu-Lys-Glu-Leu-Leu-Glu-Lys-Leu-Lys-Glu-Lys-Leu-Ala FG. 1. Amino acid sequence of the synthetic amphiphilic peptide (6) O - A \ 0 z - 0 % 2 bj 5 O O* X TOTAL CONCENTRATON OF PROTEN OR PEPTDE (g/l) FG. 2. Binding profiles of ligands to unilamellar vesicles measured as described under Experimental Procedures (see Miniprint), 22 C, in M morpholinopropanesulfonic acid, 0.16 M KC1 buffer, ph 7.5. A: 0, apo A- binding to 2.4 x M phospholipid; 0, apo A- binding to mixedvesicleswith 5.6 X M phospholipid. B: 0, peptide binding to 9.7 X M phospholipid; 0, peptide binding to mixed vesicles with 3.5 X M phospholipid. The solid lines are theoretical Langmuir isotherms calculated from Equation 2 (see text), using K, and N values shown in Table. analysis of the chromatographed vesicles also showed that the cholesterol/phospholipid ratio was identical to that found for the pure vesicles. This is eminently consistent with earlier observations that apo A- bound to egg lecithin-cholesterol vesicles neither changes their electron micrographic appearance nor the leakage of trapped [14C]glucose(8). The profdes for the isothermal equilibrium binding of apo A- and of synthetic peptide to unilamellar egg lecithin vesicles are shown in Fig. 2. The data were analyzed, assuming a single equilibrium, according to Equation 1 where Pf is the concentration of free protein, Pb is the concentration of bound protein, [PC] is the analytical concentration of lecithin in the reaction mixture, and N is the upper limit of Pb/[PC]. n our model, we assume that the binding occurs to a given proportion of the surface of the vesicles, in which case the total concentration of the surface available for binding, expressed in terms of peptide equivalents, is equal to N-[Pq. Such a model is mathematically equivalent to the one where the surface contains a finite number of discrete, equivalent, and noninteracting binding sites. The concentration of the unoccupied binding sites is then equal to N. [PC] - Pt,, and thus the dissociation constant can be defined as Kd = (N[PC]- Pb)Pf/Pb. As shown in Fig. 3, Equation 1 adequately describes the binding phenomena and yields the parameters given in Table. Pi = (N[PC]Pi/Pb) - Kd (1) [PC] xpf/pb (g/l) FG. 3. Linearized plots of the data from Fig. 2 according to Equation 1. The solid lines represent the least squares fit to the data. When cholesterol was mixed with lecithin (4 mol of lecithin/ mol of cholesterol) to give mixed unilamellar vesicles, the binding capacity of the vesicles increased in the cases of both apo A- and the peptide (Figs. 2 and 3, Table ). t increased by 1.95 X protein/molecule of lecithin and 1.21 X peptide/molecule of lecithin (an increase in the number of molecules bound by 113 and 80%, respectively). The presence of cholesterol in the vesicles results in an increase in the Kd for peptide binding and a decrease in the Kd for apo A- binding (Table 1). Binding studies at 37 C indicated that the binding parameters Kd and N are essentially the same as at 22 C. The initial rates of reaction with 1ecithin:cholesterol acyltransferase with pure lecithin vesicles or lecithin-cholesterol mixed vesicles (4:l molar ratio) were measured by radioactive labeling techniques in the presence of apo A- or the peptide. Gel permeation chromatography showed that K,, values of the vesicles are the same before and after the 1ecithin:cholesterol acyltransferase reaction (involving up to at least 5% esterification of the cholesterol molecules for the mixed vesicles), and the analysis of the peak fractions after the reaction revealed that the esterified cholesterol remains on the vesicle. The reactions monitored included cholesterol esterification, fatty acyl transfer from lecithin to cholesterol, and fatty acid release. Since the rates of reaction of 1ecithin:cholesterol acyltransferase depended somewhat on chemical the nature of the fatty acyl group, and the lecithin used as the substrate was

3 Peptide Activator of Lecithin:Cholesterol Acyltransferase 7335 TABLE Parameters for the binding of ape A- and of the amphiphilic peptide to lecithin and lecithin-cholesterol unilamellar vesicles K, is a dissociation constant and N is the upper limit of binding, as defined in Equation 1. The values correspond to the intercept on the ordinate (-&) and to the slope (N) of the least squares regressed line in Fig. 3. The details of the measurement of binding are described in the Miniprint. Substrate concentrations are as listed in the legend for Fig. 3. Preliminary values of the parameters for the lecithin vesicles without cholesterol were published in a communication (6). Kd N Activator Mol S Cholesterol M g/liter mol peptide/mol PL g/g Apo A x lo-; 2.52 x lo-' 1.74 x lo-" 6.29 X O-" x 10-j 8.40 x lo-' 3.70 x lo-' x 10-j Peptide x 10-h 5.07 x lo-" 1.51 x lo x 10 L x Wh 7.39 x 10-l 2.72 x lo X O- PL, phospholipid. 0 5 O O X COFACTOR CONCENTRATON N NCUBATON MXTURE (g/ 1 FG. 4. The rate of the reaction of [%]cholesterol esterlfication by 1ecithin:cholesterol acyltransferase using the lecithin-cholesterol mixed vesicles (4:1, mol/mol) as a substrate, in the presence of various amounts of apo A- (0) or the peptide (0). The inset shows the same rates as a function of the amounts of apo A- (0) or the peptide (0) bound to the mixed vesicles. The arrows show the maximum binding of the ligand. The solid lines in the inset show the least squares fit of the data to the equation VL~~~ = apa + b where Pb was calculated from Equation 2. Using the values of a and b, the solid lines in the main figure were calculated from the same equation. Substrate concentrations were 3.6 X 10h4 M lecithin, 9.0 X 10e5 M cholesterol in 0.02 M morpholinopropanesulfonic acid, 0.16 M KC1 buffer, ph 7.4. The final volume, 270 pl, included 2 pg of enzyme. not homogeneous, there was a possibility that the rate of fatty acyl transfer, as monitored by incorporation of the [ H]oleoyl group into the cholesteryl ester, could be different from the rate of cholesterol esterification, as monitored by the use of [ C]cholesterol. The dependencies of the initial rates of the enzyme-catalyzed reactions upon the concentration of apo A- or the peptide are illustrated in Figs. 4 and 5. All the experimental curves displayed a well defined saturation phenomenon; i.e the rate became independent of activator concentration at high concentrations. We have tried a variety of obvious mechanistic schemes to account for this saturation phenomenon, such as complex formation between peptide and enzyme in solution, on the surface, or a combination of these, prevention of surface denaturation by the peptide, inhibitory complex formation, etc., but the only linear correlation we were able to find was the one relating rate to the amount of activator bound to the vesicle (8) (see inset to Fig. 4). For this reason, all the other results in Fig. 5 are presented according to this relationship. For this interpretation, the concentration of the 10~ x BOUND COFACTOR /LECTHN (g/g) FG. 5. The 1ecithin:cholesterol acyltransferase-catalyzed rates of acyl transfers from r3h]lecithin in the presence of apo A- (A) or the peptide (B). The rate of oleic acid formation from A, egg lecithin vesicles, 0, lecithin-cholesterol mixed vesicles (4:1, mol/mol). 0, the rate of transesterification to cholesterol. The solid lines show the least squares fit to the data. The conditions for the reactions are the same as described for Fig. 4. activator bound was calculated from the independently determined binding parameters using Equation 2, derived from Equation 1 after substituting (P,,,, - Pb) for P/ where P,,,,,, corresponds to the total concentration of the activator in the mixture. Pb = (Kd + N[PC] + P& - \i(kd + N[PC] + P,,& - QN[PC].P,ti (2) Taking the maximum activation by apo A- as being loo%, the maximum activation observed for the peptide was 18% for cholesterol esterification (Fig. 4), 10% for oleoyl transfer from lecithin to cholesterol, and 50% for catalysis of fatty acid release from lecithin, using mixed vesicles (Fig. 5). n a similar manner, when pure lecithin vesicles were used, the phospholipase Aa activity of 1ecithin:cholesterol acyltransferase was activated by apo A- 2.7 times more than by the peptide (Fig. 5). Using a sample of 17,000 times purified 1ecithin:cholesterol acyltransferase provided by Drs. J. Chung and A. M. Scanu (9), the relative activation due to the amphiphilic peptide and apo A- was the same as that for our enzyme. Competition experiments indicated that the simultaneous presence of the peptide and of apo A- in the reaction mixture resulted in a rate which was intermediate between that found for the individual activators at the same concentration. Thus, the two effecters must compete with each other in their ability to increase the rate of the enzyme-catalyzed reaction. 2

4 7336 Peptide Activator of Lecithin:CholesteroL Acyltransferase DSCUSSON fatty acid products remain on the surface of the vesicles. Also, The results presented in this paper demonstrate that a both the enzyme and the activator bind to the vesicle and synthetic peptide designed for optimizing amphiphilic a-helix formation is able to activate the reactions catalyzed by lecithin:cholesterol acyltransferase. All characteristics of activation by the peptide are similar to those for the physiological activator apo A-: (a) the activation reaches a saturation limit maximum activation occurs upon maximum binding, any further increase of activator in solution being without effect, on the reaction. The activator dependency of the rates of 1ecithin:cholesterol acyltransferase-catalyzed hydrolysis and ester formation also when the concentration of the activator increases; (6) the shed light on the mechanism of the enzymatic acyl transfer. absolute amount of activator required for saturation is about the same for both systems; (c) the presence of cholesterol Our data show that the rate of disappearance of lecithin at maximal activation is the same in the absence presence and of results in acyl transfer to cholesterol and a simultaneous cholesterol for both activators (Fig. 5), whereas the rate of decrease in the rate of transfer to water for both activators; hydrolysis decreases and that of ester formation increases and (d) the ratio of the rates of these two transfer reactions upon addition of cholesterol (Fig. 5). Aron et al. (12) also is approximately the same for both systems. The only differ- observed a linear decrease of the rate of hydrolysis and a ences between the peptide and apo A- is quantitative: the linear increase of the rate of transesterification with increasing protein is some four times more efficient than the peptide at the same weight-based concentration. From this comparison, cholesterol mole fraction. These results thus show that the reactions of hydrolysis and of ester formation pass through a we can conclude that the mechanism of activation is the same common intermediate-in all probability an acyl enzymefor the peptide as for apo A-. The mode of binding of the peptide and of apo A- to the formation of which is rate-limiting. Most importantly, cholesterol and water react with the intermediate in a step phospholipid or to mixed vesicles is also the same: (a) both which is not rate-limiting! Thus, activation of 1ecithin:cholesbind to the vesicles according to a simple isotherm without terol acyltransferase by apo A- or peptides cannot occur disruption of the bilayer structure as evidenced by the absence of a change in size: (b) the capacity of the vesicles is comparable for both; and (c) cholesterol increases the binding cathrough activation of the cholesterol molecule and, thus, it must involve either activation of the enzyme and/or of the phospholipid molecule. pacity for both by about the same extent. This increased Activation of the enzyme itself appears unlikely since the capacity could occur a priori either by specific complex for- (rate)/(concentration of activator) relationships observed are mation between the peptide chain and cholesterol or by inconsistent with a simple complex formation between the creating additional space on the surface through insertion of enzyme and the surface-bound activator. Also, maximum acthe somewhat shorter cholesterol molecule into the phospho- tivation occurs only when the surface is saturated with the lipid monolayer. The binding of the peptide and of apo A- activator, and the enzymatic rate is linearly related to the obeying a single equilibrium even in the case of mixed vesicles amount of surface-bound activator (see Figs. 4 and 5), whether would argue against the former possibility. Furthermore, interpolation from the data of Newman and Huang (O) indicates that our vesicles containing 20 mol % of cholesterol contained 573 molecules of cholesterol and 2290 molecules of phospholipid for a radius of 114 A. n comparison, the phospholipid vesicles contained 2335 molecules of phospholipids for a radius of A. f the partitioning of the cholesterol between the outer and inner monolayers is 70:30 as it is for phospholipids, then the insertion of 401 cholesterols with an average area of52 A'/molecule into the outer layer would create an area amply sufficient for accommodating the additional four apo A- or 21 peptide molecules since each amino acid in them should occupy about A'. Thus, our data are well consistent with a binding through insertion of helical segments of peptides between the head groups of phospholipids and overlapping the chvlesterol molecules. n a recent communication, Lala et al. (11) showed that the alcohol function of cholesterol is not necessary for insertion into biological membranes. This observation also strongly supports the hypothesis that cholesterol is not located at the hydrophilic surface of the monolayer but rather is totally inserted in the hydrophobic portion. The relative insensitivity of the binding affinity and the absence of different types of binding with mixed vesicles would thus argue against specific complex formation between the peptide chains and either phospholipid or cholesterol. Finally, the similarity of the molar free energies of binding (-8 kcal/mol) for both the peptide and apo A- does not necessarily indicate that only a small portion of apo A- participates in the binding since the peptide is predominantly monomolecular in our experimental system, whereas the binding of apo A- must involve the disruption of its considerably tertiary and possibly quarternary structure. The location of the 1ecithin:cholesterol acyltransferase-cat- alyzed reaction is on the surface of the unilamellar vesicles since the particles remain intact and the cholesteryl ester and the surface is that of a phospholipid vesicle or of a cholesterolphospholipid mixed vesicle. t is also unlikely that the role of act,ivator would be to prevent some reversible surface denaturation of the enzyme through occupancy of the surface necessary for the partial unfolding of the enzyme since such a mechanism would require identical activation of both peptide and apo A- when the inhibitors occupy the same area. For the above reasons, we would like to conclude that the activation of the 1ecithin:cholesterol acyltransferase-catalyzed reactions occurs through the activation of the phospholipid and not of the enzyme. At the present time, we can only speculate as to the exact mechanism of this activation. t is perhaps relevant consider to that many peptides and proteins can activate 1ecithin:cholesterol acyltransferase (13-16) and that a strong correlation can be found between the activating ability and the amphiphilic helix-forming ability of the activator bound to the phospholipid surface (17). Thus, binding to the surface is necessaary but not sufficient. Since a helix with more than a third of its surface being hydrophobic must penetrate deeper into the phospholipid monolayer than the unfolded peptide chain, the activation could be correlated with the interaction of the protein with the phospholipid side chains at some distance from the interface. When the surface is not covered by the activator, the gaps between the phospholipid head groups are most likely to be occupied by the olefinic carbons of the unsaturated fatty acid side chain usually in position 2. The binding of the activator must result in the transfer of the olefinic group into the hydrophobic region of the monolayer, and such a transfer must be accompanied by a reorientation of the ester linkage susceptible to enzymatic attack. t is then possible to surmise that the role of the activators of lecithin: cholesterol acyltransferase would be to effect this reorientation through displacement of the double bond from the surface. Since the exclusion of the hydrophilic double bond from

5 Peptide Activator the surface would only OCCLU when the available free surface is below a certain minimum, such an activation mechanism would provide an explanation for the lack of activation below a certain lower limit of bound activator, as observed through the occurrence of a negative intercept on the y axis in Fig. 4 in the case of both activators. Perhaps this activation mechanism could also explain readily the lack of action of lecithin: cholesterol acyltransferase on low density lipoprotein if apo B is much less helical than the apo A- protein. Also, it explains why it is not necessary to have a particularly well defined primary sequence in the activator. The crucial factor for the activation of 1ecithin:cholesterol acyltransferase by a peptide is simply the presence of a large enough amphiphilic structure. Acknowledgments-We thank Dr. R. L. Heinrikson for the sequence analysis of the peptide and Dr. A. M. Scanu for providing samples of apo A- and of 1ecithin:cholesterol acyltransferase. REFERENCES 1. Shen, B. W., Scanu, A. M., and Kezdy, F. J. (1977) Proc. Natl. Acad. Sei. U. S. A. 74, Edelstein, D., Kezdy, F. J., Scanu, A. M., and Shen, B. W. (1979) J. Lipid Res. 20, Fitch, W. M. (1977) Genetics 86, Segrest, J. P., Jackson, R. L., Morrisett, J. D., and Gotto, A. M., Jr. (1974) FEBS Lett 38, Shen, B., Scanu, A. M., and Kezdy, F. J. (1973) Circulation 48, Suppl. V, 214 of Lecithin:Cholesterol Acyltransferase Fukushima, D., Kupferberg, J. P., Yokoyama, S., Kroon, D. J., Kaiser, E. T., and Kezdy, F. J. (1979) J. Am. Chem. Soc. 101, Fielding, C. J., Shore, V. G., and Fielding, P. E. (1972) Biochem. Biophys. Res. Commun. 46, Yokoyama, S., Murase, T., and Akanuma, Y. (1978) Biochim. Biophys. Acta 530, Chung, J., Abano, D. A,, Ness, G. M., and Scanu, A. M. (1979) J. Biol. Chem. 254, Newman, G. C., and Huang, C. (1975) Biochemistry 14, Lala, A. K., Buttke, T. M., and Bloch, K. (1979) J. Biol. Chem. 254, Aron, L., Jones, S., and Fielding, C. J. (1978) J. Biol. Chem. 253, Soutar, A. K., Garner, C. W., Baker, H. N., Sparrow, J. T.. Jackson, R. L., Gotto, A. M., and Smith, L. C. (1975) Biochemistry 14, Sigler, G. F., Soutar, A. K., Smith, L. C., Gotto, A. M., Jr., and Sparrow, J. T. (1976) Proc. Natl. Acad. Sci. U. S. A. 73, Albers, J. J. (1978) Scand. J. Clin. Lab. nuest. 38, Suppl. 150, Soutar, A. K., Sigler, G. F., Smith, L. C., Gotto, A. M., Jr., and Sparrow, J. T. (1978) Scand. J. Clin. Lab. hued. 38, Suppl. 150, Morrisett, J. D., Jackson, R. L., and Gotto, A. M., Jr. (1977) Biochim. Biophys. Acta 472, Additional references are found on pp

6 7338 Peptide Activator of Lecithin:Cholesterol Acyltransferase

7 :Cholesterol Acyltransferase ELUTED VOLUME (ml) [Pept~de] x 10' (M) 7 16

Binding of amphiphilic peptides to phospholipid/cholesterol unilamellar vesicles: A model for protein-cholesterol interaction (apolipoprotein A-I)

Binding of amphiphilic peptides to phospholipid/cholesterol unilamellar vesicles: A model for protein-cholesterol interaction (apolipoprotein A-I) Proc. Nati. Acad. Sci. USA Vol. 78, No. 5, pp. 2732-2736, May 1981 Biochemistry Binding of amphiphilic peptides to phospholipid/cholesterol unilamellar vesicles: A model for protein-cholesterol interaction

More information

Supplementary Figures

Supplementary Figures Supplementary Figures Supplementary Figure 1. (a) Uncropped version of Fig. 2a. RM indicates that the translation was done in the absence of rough mcirosomes. (b) LepB construct containing the GGPG-L6RL6-

More information

2. Which of the following amino acids is most likely to be found on the outer surface of a properly folded protein?

2. Which of the following amino acids is most likely to be found on the outer surface of a properly folded protein? Name: WHITE Student Number: Answer the following questions on the computer scoring sheet. 1 mark each 1. Which of the following amino acids would have the highest relative mobility R f in normal thin layer

More information

Interaction of Apolipoprotein A-I with Dimyristoylphosphatidylcholine Particles of Various Sizes*

Interaction of Apolipoprotein A-I with Dimyristoylphosphatidylcholine Particles of Various Sizes* THE JOURNAL OF BOLOGCAL CHEM~STHY Vol. 256. No. 5, swe of March O. pp. 2420442fi, 1981 Printed n 1J.S.A. nteraction of Apolipoprotein A- with Dimyristoylphosphatidylcholine Particles of Various Sizes*

More information

Movement of Cholesterol between Vesicles Prepared with Different Phospholipids or Sizes*

Movement of Cholesterol between Vesicles Prepared with Different Phospholipids or Sizes* THE JOURNAL OF BIOLOGICAL CHEMISTRY 0 1985 by The American Society of Biological Chemists, Inc. Vol. 260, No. 7, Issue of April 10, pp. 4098-4102 1985 Printed in ~ s.a. Movement of Cholesterol between

More information

A Molecular Model of High Density Lipoproteins

A Molecular Model of High Density Lipoproteins Proc. Nat. Acad. Sci. USA Vol. 71, No. 4, pp. 1534-1538, April 1974 A Molecular Model of High Density Lipoproteins (assembly of proteins and lipids/amphipathic a-helical regions/hydrophobicity of apoproteins)

More information

Chapter 2 Transport Systems

Chapter 2 Transport Systems Chapter 2 Transport Systems The plasma membrane is a selectively permeable barrier between the cell and the extracellular environment. It permeability properties ensure that essential molecules such as

More information

1. Which of the following statements about passive and primary active transport proteins is FALSE?

1. Which of the following statements about passive and primary active transport proteins is FALSE? Biological Membranes 1. Which of the following statements about passive and primary active transport proteins is FALSE? A. They are both integral membrane proteins. B. They both show a high degree of selectivity.

More information

UNIVERSITY OF GUELPH CHEM 4540 ENZYMOLOGY Winter 2005 Quiz #2: March 24, 2005, 11:30 12:50 Instructor: Prof R. Merrill ANSWERS

UNIVERSITY OF GUELPH CHEM 4540 ENZYMOLOGY Winter 2005 Quiz #2: March 24, 2005, 11:30 12:50 Instructor: Prof R. Merrill ANSWERS UNIVERSITY F GUELPH CHEM 4540 ENZYMLGY Winter 2005 Quiz #2: March 24, 2005, 11:30 12:50 Instructor: Prof R. Merrill ANSWERS Instructions: Time allowed = 80 minutes. Total marks = 30. This quiz represents

More information

The MOLECULES of LIFE

The MOLECULES of LIFE The MOLECULES of LIFE Physical and Chemical Principles Solutions Manual Prepared by James Fraser and Samuel Leachman Chapter 16 Principles of Enzyme Catalysis Problems True/False and Multiple Choice 1.

More information

8 Influence of permeation modulators on the behaviour of a SC lipid model mixture

8 Influence of permeation modulators on the behaviour of a SC lipid model mixture 8 Influence of permeation modulators on the behaviour of a SC lipid model mixture 8.1 Introduction In the foregoing parts of this thesis, a model membrane system of SC lipids has been developed and characterized.

More information

A Kinetic Study of Glucose-6-phosphate Dehydrogenase

A Kinetic Study of Glucose-6-phosphate Dehydrogenase A Kinetic Study of Glucose-6-phosphate Dehydrogenase (Received for publication, September 10, 1975) MOHAMMED. KANJ, MYRON L. TOEWS, AND W. ROBERT CARPER* From the Department of Chemistry, Wichita State

More information

االمتحان النهائي لعام 1122

االمتحان النهائي لعام 1122 االمتحان النهائي لعام 1122 Amino Acids : 1- which of the following amino acid is unlikely to be found in an alpha-helix due to its cyclic structure : -phenylalanine -tryptophan -proline -lysine 2- : assuming

More information

AP Biology Summer Assignment Chapter 3 Quiz

AP Biology Summer Assignment Chapter 3 Quiz AP Biology Summer Assignment Chapter 3 Quiz 2016-17 Multiple Choice Identify the choice that best completes the statement or answers the question. 1. All of the following are found in a DNA nucleotide

More information

Chapter 2 The Chemistry of Life Part 2

Chapter 2 The Chemistry of Life Part 2 Chapter 2 The Chemistry of Life Part 2 Carbohydrates are Polymers of Monosaccharides Three different ways to represent a monosaccharide Carbohydrates Carbohydrates are sugars and starches and provide

More information

BIOCHEMISTRY 460 FIRST HOUR EXAMINATION FORM A (yellow) ANSWER KEY February 11, 2008

BIOCHEMISTRY 460 FIRST HOUR EXAMINATION FORM A (yellow) ANSWER KEY February 11, 2008 WRITE YOUR AND I.D. NUMBER LEGIBLY ON EVERY PAGE PAGES WILL BE SEPARATED FOR GRADING! CHECK TO BE SURE YOU HAVE 6 PAGES, (print): ANSWERS INCLUDING COVER PAGE. I swear/affirm that I have neither given

More information

Chapter 1 Membrane Structure and Function

Chapter 1 Membrane Structure and Function Chapter 1 Membrane Structure and Function Architecture of Membranes Subcellular fractionation techniques can partially separate and purify several important biological membranes, including the plasma and

More information

بسم هللا الرحمن الرحيم

بسم هللا الرحمن الرحيم بسم هللا الرحمن الرحيم Q1: the overall folding of a single protein subunit is called : -tertiary structure -primary structure -secondary structure -quaternary structure -all of the above Q2 : disulfide

More information

Previous Class. Today. Term test I discussions. Detection of enzymatic intermediates: chymotrypsin mechanism

Previous Class. Today. Term test I discussions. Detection of enzymatic intermediates: chymotrypsin mechanism Term test I discussions Previous Class Today Detection of enzymatic intermediates: chymotrypsin mechanism Mechanistic Understanding of Enzymemediated Reactions Ultimate goals: Identification of the intermediates,

More information

Problem-solving Test: The Mechanism of Protein Synthesis

Problem-solving Test: The Mechanism of Protein Synthesis Q 2009 by The International Union of Biochemistry and Molecular Biology BIOCHEMISTRY AND MOLECULAR BIOLOGY EDUCATION Vol. 37, No. 1, pp. 58 62, 2009 Problem-based Learning Problem-solving Test: The Mechanism

More information

The Structure and Function of Large Biological Molecules

The Structure and Function of Large Biological Molecules NAME DATE Chapter 5 - The Structure and Function of Large Biological Molecules Guided Reading Concept 5.1: Macromolecules are polymers, built from monomers 1. The large molecules of all living things fall

More information

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. Practice Quiz 1 AP Bio Sept 2016 Name MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) The element present in all organic molecules is A) hydrogen.

More information

Review of Biochemistry

Review of Biochemistry Review of Biochemistry Chemical bond Functional Groups Amino Acid Protein Structure and Function Proteins are polymers of amino acids. Each amino acids in a protein contains a amino group, - NH 2,

More information

NANO 243/CENG 207 Course Use Only

NANO 243/CENG 207 Course Use Only L9. Drug Permeation Through Biological Barriers May 3, 2018 Lipids Lipid Self-Assemblies 1. Lipid and Lipid Membrane Phospholipid: an amphiphilic molecule with a hydrophilic head and 1~2 hydrophobic tails.

More information

1. Denaturation changes which of the following protein structure(s)?

1. Denaturation changes which of the following protein structure(s)? Chem 11 Fall 2008 Examination #5 ASWER KEY MULTIPLE CICE (20 pts. total; 2 pts. each) 1. Denaturation changes which of the following protein structure(s)? a. primary b. secondary c. tertiary d. both b

More information

Quiz 4 Review Guide Fall 2018

Quiz 4 Review Guide Fall 2018 Quiz 4 Review Guide Fall 2018 Major Topics: Enzyme Kinetics: o reaction rates and catalysis; transition state binding theory o Michaelis-Menten equation and interpretation o Inhibitors types and explanations

More information

Acid/Base chemistry. NESA Biochemistry Fall 2001 Review problems for the first exam. Complete the following sentences

Acid/Base chemistry. NESA Biochemistry Fall 2001 Review problems for the first exam. Complete the following sentences 1 NESA Biochemistry Fall 2001 eview problems for the first exam Acid/Base chemistry 1. 2 3 is a weak acid. 2. The anion of a weak acid is a weak base 3. p is the measure of a solutions acidity. 4. 3 and

More information

Six Types of Enzyme Catalysts

Six Types of Enzyme Catalysts Six Types of Enzyme Catalysts Although a huge number of reactions occur in living systems, these reactions fall into only half a dozen types. The reactions are: 1. Oxidation and reduction. Enzymes that

More information

Previous Class. Today. Detection of enzymatic intermediates: Protein tyrosine phosphatase mechanism. Protein Kinase Catalytic Properties

Previous Class. Today. Detection of enzymatic intermediates: Protein tyrosine phosphatase mechanism. Protein Kinase Catalytic Properties Previous Class Detection of enzymatic intermediates: Protein tyrosine phosphatase mechanism Today Protein Kinase Catalytic Properties Protein Phosphorylation Phosphorylation: key protein modification

More information

Find this material useful? You can help our team to keep this site up and bring you even more content consider donating via the link on our site.

Find this material useful? You can help our team to keep this site up and bring you even more content consider donating via the link on our site. Find this material useful? You can help our team to keep this site up and bring you even more content consider donating via the link on our site. Still having trouble understanding the material? Check

More information

Statin inhibition of HMG-CoA reductase: a 3-dimensional view

Statin inhibition of HMG-CoA reductase: a 3-dimensional view Atherosclerosis Supplements 4 (2003) 3/8 www.elsevier.com/locate/atherosclerosis Statin inhibition of HMG-CoA reductase: a 3-dimensional view Eva Istvan * Department of Molecular Microbiology, Howard Hughes

More information

Multiple-Choice Questions Answer ALL 20 multiple-choice questions on the Scantron Card in PENCIL

Multiple-Choice Questions Answer ALL 20 multiple-choice questions on the Scantron Card in PENCIL Multiple-Choice Questions Answer ALL 20 multiple-choice questions on the Scantron Card in PENCIL For Questions 1-10 choose ONE INCORRECT answer. 1. Which ONE of the following statements concerning the

More information

Chemistry 135, First Exam. September 23, Chem 135, Exam 1 SID:

Chemistry 135, First Exam. September 23, Chem 135, Exam 1 SID: Chemistry 135, First Exam September 23, 2015 This exam will be worth 15% of your overall grade. Please read all instructions/questions carefully and provide answers in the space provided. There should

More information

SYNOPSIS STUDIES ON THE PREPARATION AND CHARACTERISATION OF PROTEIN HYDROLYSATES FROM GROUNDNUT AND SOYBEAN ISOLATES

SYNOPSIS STUDIES ON THE PREPARATION AND CHARACTERISATION OF PROTEIN HYDROLYSATES FROM GROUNDNUT AND SOYBEAN ISOLATES 1 SYNOPSIS STUDIES ON THE PREPARATION AND CHARACTERISATION OF PROTEIN HYDROLYSATES FROM GROUNDNUT AND SOYBEAN ISOLATES Proteins are important in food processing and food product development, as they are

More information

Inorganic compounds: Usually do not contain carbon H 2 O Ca 3 (PO 4 ) 2 NaCl Carbon containing molecules not considered organic: CO 2

Inorganic compounds: Usually do not contain carbon H 2 O Ca 3 (PO 4 ) 2 NaCl Carbon containing molecules not considered organic: CO 2 Organic Chemistry The study of carbon-containing compounds and their properties. Biochemistry: Made by living things All contain the elements carbon and hydrogen Inorganic: Inorganic compounds: All other

More information

For questions 1-4, match the carbohydrate with its size/functional group name:

For questions 1-4, match the carbohydrate with its size/functional group name: Chemistry 11 Fall 2009 Examination #5 ANSWER KEY For the first portion of this exam, select the best answer choice for the questions below and mark the answers on your scantron. Then answer the free response

More information

Kinetics of a-chymotrypsin action Mechanisms of inhibition

Kinetics of a-chymotrypsin action Mechanisms of inhibition Kinetics of a-chymotrypsin action. 111. Mechanisms of inhibition HARVEY KAPLAN AND KEITH J. LAIDLER Department of Chemistry, Unzversity of Ottawa, Ottawa, Canada Received April 26, 1966 An experimental

More information

Biochemistry and Physiology ID #:

Biochemistry and Physiology ID #: BM 463 Your Name: Biochemistry and Physiology ID #: Final Exam, December 18, 2002 Prof. Jason Kahn You have 115 minutes for this exam. It is worth 250 points, so you are getting more points per minute

More information

/ The following functional group is a. Aldehyde c. Carboxyl b. Ketone d. Amino

/ The following functional group is a. Aldehyde c. Carboxyl b. Ketone d. Amino Section A: Multiple Choice Select the answer that best answers the following questions. Please write your selected choice on the line provided, in addition to circling the answer. /25 1. The following

More information

Lecture Series 5 Cellular Membranes

Lecture Series 5 Cellular Membranes Lecture Series 5 Cellular Membranes Cellular Membranes A. Membrane Composition and Structure B. Animal Cell Adhesion C. Passive Processes of Membrane Transport D. Active Transport E. Endocytosis and Exocytosis

More information

A. Membrane Composition and Structure. B. Animal Cell Adhesion. C. Passive Processes of Membrane Transport. D. Active Transport

A. Membrane Composition and Structure. B. Animal Cell Adhesion. C. Passive Processes of Membrane Transport. D. Active Transport Cellular Membranes A. Membrane Composition and Structure Lecture Series 5 Cellular Membranes B. Animal Cell Adhesion E. Endocytosis and Exocytosis A. Membrane Composition and Structure The Fluid Mosaic

More information

Lipids: Membranes Testing Fluid Mosaic Model of Membrane Structure: Cellular Fusion

Lipids: Membranes Testing Fluid Mosaic Model of Membrane Structure: Cellular Fusion Models for Membrane Structure NEW MODEL (1972) Fluid Mosaic Model proposed by Singer & Nicholson Lipids form a viscous, twodimensional solvent into which proteins are inserted and integrated more or less

More information

Biological Molecules B Lipids, Proteins and Enzymes. Triglycerides. Glycerol

Biological Molecules B Lipids, Proteins and Enzymes. Triglycerides. Glycerol Glycerol www.biologymicro.wordpress.com Biological Molecules B Lipids, Proteins and Enzymes Lipids - Lipids are fats/oils and are present in all cells- they have different properties for different functions

More information

Point total. Page # Exam Total (out of 90) The number next to each intermediate represents the total # of C-C and C-H bonds in that molecule.

Point total. Page # Exam Total (out of 90) The number next to each intermediate represents the total # of C-C and C-H bonds in that molecule. This exam is worth 90 points. Pages 2- have questions. Page 1 is for your reference only. Honor Code Agreement - Signature: Date: (You agree to not accept or provide assistance to anyone else during this

More information

Will s Pre-Test. (4) A collection of cells that work together to perform a function is termed a(n): a) Organelle b) Organ c) Cell d) Tissue e) Prison

Will s Pre-Test. (4) A collection of cells that work together to perform a function is termed a(n): a) Organelle b) Organ c) Cell d) Tissue e) Prison Will s Pre-Test This is a representative of Exam I that you will take Tuesday September 18, 2007. The actual exam will be 50 multiple choice questions. (1) The basic structural and functional unit of the

More information

Nafith Abu Tarboush DDS, MSc, PhD

Nafith Abu Tarboush DDS, MSc, PhD Nafith Abu Tarboush DDS, MSc, PhD natarboush@ju.edu.jo www.facebook.com/natarboush Lipids (cholesterol, cholesterol esters, phospholipids & triacylglycerols) combined with proteins (apolipoprotein) in

More information

Biology 2180 Laboratory #3. Enzyme Kinetics and Quantitative Analysis

Biology 2180 Laboratory #3. Enzyme Kinetics and Quantitative Analysis Biology 2180 Laboratory #3 Name Introduction Enzyme Kinetics and Quantitative Analysis Catalysts are agents that speed up chemical processes and the catalysts produced by living cells are called enzymes.

More information

Student Handout. This experiment allows you to explore the properties of chiral molecules. You have

Student Handout. This experiment allows you to explore the properties of chiral molecules. You have Student Handout This experiment allows you to explore the properties of chiral molecules. You have learned that some compounds exist as enantiomers non-identical mirror images, such as your left and right

More information

BIOLOGICAL MOLECULES REVIEW-UNIT 1 1. The factor being tested in an experiment is the A. data. B. variable. C. conclusion. D. observation. 2.

BIOLOGICAL MOLECULES REVIEW-UNIT 1 1. The factor being tested in an experiment is the A. data. B. variable. C. conclusion. D. observation. 2. BIOLOGICAL MOLECULES REVIEW-UNIT 1 1. The factor being tested in an experiment is the A. data. B. variable. C. conclusion. D. observation. 2. A possible explanation for an event that occurs in nature is

More information

Phase Transition Behaviours of the Supported DPPC Bilayer. Investigated by Sum Frequency Generation (SFG) and Atomic Force

Phase Transition Behaviours of the Supported DPPC Bilayer. Investigated by Sum Frequency Generation (SFG) and Atomic Force Electronic Supplementary Material (ESI) for Physical Chemistry Chemical Physics. This journal is the Owner Societies 2015 Supporting Information for Phase Transition Behaviours of the Supported DPPC Bilayer

More information

Section 1 Lecture 1- Origins of Life Life probably started by Hydrothermal Vents.

Section 1 Lecture 1- Origins of Life Life probably started by Hydrothermal Vents. Section 1 Lecture 1- Origins of Life Life probably started by Hydrothermal Vents. Photosynthesis originated around 3GA, as cells figured out how to fix CO2 and release O2. Eukaryotes originates 1.5-2.5

More information

FIRST BIOCHEMISTRY EXAM Tuesday 25/10/ MCQs. Location : 102, 105, 106, 301, 302

FIRST BIOCHEMISTRY EXAM Tuesday 25/10/ MCQs. Location : 102, 105, 106, 301, 302 FIRST BIOCHEMISTRY EXAM Tuesday 25/10/2016 10-11 40 MCQs. Location : 102, 105, 106, 301, 302 The Behavior of Proteins: Enzymes, Mechanisms, and Control General theory of enzyme action, by Leonor Michaelis

More information

1. Measurement of the rate constants for simple enzymatic reaction obeying Michaelis- Menten kinetics gave the following results: =3x10-5 = 30μM

1. Measurement of the rate constants for simple enzymatic reaction obeying Michaelis- Menten kinetics gave the following results: =3x10-5 = 30μM 1. Measurement of the rate constants for simple enzymatic reaction obeying Michaelis- Menten kinetics gave the following results: k 1 = 2 x 10 8 M -1 s -1, k 2 = 1 x 10 3 s -1, k 3 = 5 x 10 3 s -1 a) What

More information

cholesterol structure Cholesterol FAQs Cholesterol promotes the liquid-ordered phase of membranes Friday, October 15, 2010

cholesterol structure Cholesterol FAQs Cholesterol promotes the liquid-ordered phase of membranes Friday, October 15, 2010 cholesterol structure most plasma cholesterol is in the esterified form (not found in cells or membranes) cholesterol functions in all membranes (drives formation of lipid microdomains) cholesterol is

More information

CHAPTER 21: Amino Acids, Proteins, & Enzymes. General, Organic, & Biological Chemistry Janice Gorzynski Smith

CHAPTER 21: Amino Acids, Proteins, & Enzymes. General, Organic, & Biological Chemistry Janice Gorzynski Smith CHAPTER 21: Amino Acids, Proteins, & Enzymes General, Organic, & Biological Chemistry Janice Gorzynski Smith CHAPTER 21: Amino Acids, Proteins, Enzymes Learning Objectives: q The 20 common, naturally occurring

More information

3.1 Carbon is Central to the Living World

3.1 Carbon is Central to the Living World BIOL 100 Ch. 3 1 3.1 Carbon is Central to the Living World Carbon Central element to life Most biological molecules are built on a carbon framework. Organic molecules Humans 18.5% Carbon Why is Carbon

More information

Lipids: diverse group of hydrophobic molecules

Lipids: diverse group of hydrophobic molecules Lipids: diverse group of hydrophobic molecules Lipids only macromolecules that do not form polymers li3le or no affinity for water hydrophobic consist mostly of hydrocarbons nonpolar covalent bonds fats

More information

Good Afternoon! 11/30/18

Good Afternoon! 11/30/18 Good Afternoon! 11/30/18 1. The term polar refers to a molecule that. A. Is cold B. Has two of the same charges C. Has two opposing charges D. Contains a hydrogen bond 2. Electrons on a water molecule

More information

Exams written in pencil or erasable ink will not be re-graded under any circumstances.

Exams written in pencil or erasable ink will not be re-graded under any circumstances. Biochemistry 461, Section I May 21, 1998 Final Exam Prof. Jason D. Kahn Your Printed ame: Your SS#: Your Signature: You have 120 minutes for this exam. The exam has 7 questions, worth 200 points. Do all

More information

The effect of phosphatidyl choline on the degradation of phosphatidyl ethanolamine by the phospholipase of post-heparin plasma or snake venom

The effect of phosphatidyl choline on the degradation of phosphatidyl ethanolamine by the phospholipase of post-heparin plasma or snake venom The effect of phosphatidyl choline on the degradation of phosphatidyl ethanolamine by the phospholipase of post-heparin plasma or snake venom WILLIAM C. VOGEL, J. L. KOPPEL, and J. H. OLWIN Coagulation

More information

shown to be distinct from LCAT activity (10, 11), no studies a 1-acyl analog ofpaf. These results thus indicate a function

shown to be distinct from LCAT activity (10, 11), no studies a 1-acyl analog ofpaf. These results thus indicate a function Proc. Natd. Acad. Sci. USA Vol. 91, pp. 635-639, June 1994 Biochemistry Hydrolysis and transesterification of platelet-activating factor by lecithin-cholesterol acyltransferase ysopbosatdyl coe/ l /W d

More information

Human Anatomy & Physiology C H A P T E R

Human Anatomy & Physiology C H A P T E R PowerPoint Lecture Slides prepared by Barbara Heard, Atlantic Cape Community College Ninth Edition Human Anatomy & Physiology C H A P T E R 2 Annie Leibovitz/Contact Press Images 2013 Pearson Education,

More information

Enzymes. Gibbs Free Energy of Reaction. Parameters affecting Enzyme Catalysis. Enzyme Commission Number

Enzymes. Gibbs Free Energy of Reaction. Parameters affecting Enzyme Catalysis. Enzyme Commission Number SCBC203 Enzymes Jirundon Yuvaniyama, Ph.D. Department of Biochemistry Faculty of Science Mahidol University Gibbs Free Energy of Reaction Free Energy A B + H 2 O A OH + B H Activation Energy Amount of

More information

Mechanisms of high density lipoprotein-mediated efflux of cholesterol from cell plasma membranes

Mechanisms of high density lipoprotein-mediated efflux of cholesterol from cell plasma membranes Atherosclerosis 137 Suppl. (1998) S13 S17 Mechanisms of high density lipoprotein-mediated efflux of cholesterol from cell plasma membranes Michael C. Phillips *, Kristin L. Gillotte, M. Page Haynes, William

More information

Short polymer. Dehydration removes a water molecule, forming a new bond. Longer polymer (a) Dehydration reaction in the synthesis of a polymer

Short polymer. Dehydration removes a water molecule, forming a new bond. Longer polymer (a) Dehydration reaction in the synthesis of a polymer HO 1 2 3 H HO H Short polymer Dehydration removes a water molecule, forming a new bond Unlinked monomer H 2 O HO 1 2 3 4 H Longer polymer (a) Dehydration reaction in the synthesis of a polymer HO 1 2 3

More information

Reduction in Serum Lecithin:Cholesterol Acyltransferase Activity Prior to the Occurrence of Ketosis and Milk Fever in Cows

Reduction in Serum Lecithin:Cholesterol Acyltransferase Activity Prior to the Occurrence of Ketosis and Milk Fever in Cows FULL PAPER Biochemistry Reduction in Serum Lecithin:Cholesterol Acyltransferase Activity Prior to the Occurrence of Ketosis and Milk Fever in Cows Hisami NAKAGAWA-UETA 1) and Norio KATOH 2) * 1) Ishikawa

More information

Biochemistry Macromolecules and Enzymes. Unit 02

Biochemistry Macromolecules and Enzymes. Unit 02 Biochemistry Macromolecules and Enzymes Unit 02 Organic Compounds Compounds that contain CARBON are called organic. What is Carbon? Carbon has 4 electrons in outer shell. Carbon can form covalent bonds

More information

A. Lipids: Water-Insoluble Molecules

A. Lipids: Water-Insoluble Molecules Biological Substances found in Living Tissues Lecture Series 3 Macromolecules: Their Structure and Function A. Lipids: Water-Insoluble Lipids can form large biological molecules, but these aggregations

More information

The main biological functions of the many varied types of lipids include: energy storage protection insulation regulation of physiological processes

The main biological functions of the many varied types of lipids include: energy storage protection insulation regulation of physiological processes Big Idea In the biological sciences, a dehydration synthesis (condensation reaction) is typically defined as a chemical reaction that involves the loss of water from the reacting molecules. This reaction

More information

Biochemistry Department. Level 1 Lecture No : 3 Date : 1 / 10 / Enzymes kinetics

Biochemistry Department. Level 1 Lecture No : 3 Date : 1 / 10 / Enzymes kinetics Biochemistry Department Level 1 Lecture No : 3 Date : 1 / 10 / 2017 Enzymes kinetics 1 Intended Learning Outcomes By the end of this lecture, the student will be able to: 1.Understand what is meant by

More information

Synthetic substrates of 1ecithin:cholesterol acyltransferase

Synthetic substrates of 1ecithin:cholesterol acyltransferase Synthetic substrates of 1ecithin:cholesterol acyltransferase Ana Jonas University of Illinois at Urbana-Champaign, 506 South Mathews Avenue, Urbana, IL 61801 Abstract Investigation of the substrate specificity

More information

Moorpark College Chemistry 11 Fall Instructor: Professor Gopal. Examination # 5: Section Five May 7, Name: (print)

Moorpark College Chemistry 11 Fall Instructor: Professor Gopal. Examination # 5: Section Five May 7, Name: (print) Moorpark College Chemistry 11 Fall 2013 Instructor: Professor Gopal Examination # 5: Section Five May 7, 2013 Name: (print) Directions: Make sure your examination contains TEN total pages (including this

More information

The effects of ph on Type VII-NA Bovine Intestinal Mucosal Alkaline Phosphatase Activity

The effects of ph on Type VII-NA Bovine Intestinal Mucosal Alkaline Phosphatase Activity The effects of ph on Type VII-NA Bovine Intestinal Mucosal Alkaline Phosphatase Activity ANDREW FLYNN, DYLAN JONES, ERIC MAN, STEPHEN SHIPMAN, AND SHERMAN TUNG Department of Microbiology and Immunology,

More information

15.1 Lipids 15.2 Fatty Acids. Copyright 2009 by Pearson Education, Inc.

15.1 Lipids 15.2 Fatty Acids. Copyright 2009 by Pearson Education, Inc. Chapter 15 Lipids 15.1 Lipids 15.2 Fatty Acids Copyright 2009 by Pearson Education, Inc. 1 Lipids Lipids are biomolecules that contain fatty acids or a steroid nucleus. soluble in organic solvents, but

More information

Opinion on the safety assessment of phospholipds obtained from egg yolk as food produced using a new process

Opinion on the safety assessment of phospholipds obtained from egg yolk as food produced using a new process EUROPEAN COMMISSION DIRECTORATE-GENERAL XXIV CONSUMER POLICY AND CONSUMER HEALTH PROTECTION Directorate B - Scientific opinions on health matters Unit B3 - Management of scientific committees II SCIENTIFIC

More information

Name: Student Number

Name: Student Number UNIVERSITY OF GUELPH CHEM 454 ENZYMOLOGY Winter 2003 Quiz #1: February 13, 2003, 11:30 13:00 Instructor: Prof R. Merrill Instructions: Time allowed = 80 minutes. Total marks = 34. This quiz represents

More information

Chapter 5: The Structure and Function of Large Biological Molecules

Chapter 5: The Structure and Function of Large Biological Molecules Chapter 5: The Structure and Function of Large Biological Molecules 1. Name the four main classes of organic molecules found in all living things. Which of the four are classified as macromolecules. Define

More information

(65 pts.) 27. (10 pts.) 28. (15 pts.) 29. (10 pts.) TOTAL (100 points) Moorpark College Chemistry 11 Spring Instructor: Professor Gopal

(65 pts.) 27. (10 pts.) 28. (15 pts.) 29. (10 pts.) TOTAL (100 points) Moorpark College Chemistry 11 Spring Instructor: Professor Gopal Moorpark College Chemistry 11 Spring 2012 Instructor: Professor Gopal Examination # 5: Section Five May 1, 2012 Name: (print) GOOD LUCK! Directions: Make sure your examination contains TWELVE total pages

More information

Lysophospholipids and fat digestibility

Lysophospholipids and fat digestibility 1 Lysophospholipids and fat digestibility Fig.1 Micelle Fat is composed mainly of triglycerides. The problem with fat digestion is that it takes place in an aqueous environment, when fat is not water soluble.

More information

Details of Organic Chem! Date. Carbon & The Molecular Diversity of Life & The Structure & Function of Macromolecules

Details of Organic Chem! Date. Carbon & The Molecular Diversity of Life & The Structure & Function of Macromolecules Details of Organic Chem! Date Carbon & The Molecular Diversity of Life & The Structure & Function of Macromolecules Functional Groups, I Attachments that replace one or more of the hydrogens bonded to

More information

Chapter 5: The Structure and Function of Large Biological Molecules

Chapter 5: The Structure and Function of Large Biological Molecules Name Period Concept 5.1 Macromolecules are polymers, built from monomers 1. The large molecules of all living things fall into just four main classes. Name them. 2. Circle the three classes that are called

More information

EDUCATIONAL OBJECTIVES

EDUCATIONAL OBJECTIVES EDUCATIONAL OBJECTIVES The lectures and reading assignments of BIS 2A are designed to convey a large number of facts and concepts that have evolved from modern studies of living organisms. In order to

More information

The Structure and Function of Macromolecules

The Structure and Function of Macromolecules The Structure and Function of Macromolecules Macromolecules are polymers Polymer long molecule consisting of many similar building blocks. Monomer the small building block molecules. Carbohydrates, proteins

More information

Interaction of Rat Lecithin-Cholesterol Acyltransferase with Rat Apolipoprotein A-I and with Lecithin-Cholesterol Vesicles

Interaction of Rat Lecithin-Cholesterol Acyltransferase with Rat Apolipoprotein A-I and with Lecithin-Cholesterol Vesicles J. Biochem. 111, 413-418 (1992) Interaction of Rat Lecithin-Cholesterol Acyltransferase with Rat Apolipoprotein A-I and with Lecithin-Cholesterol Vesicles Yuji Furukawa,1 Takashi Urano,2 Yoshifumi Hida,1

More information

By: Dr Hadi Mozafari 1

By: Dr Hadi Mozafari 1 Biological lipids are a chemically diverse group of compounds, the common and defining feature of which is their insolubility in water. By: Dr Hadi Mozafari 1 Fats and oils are the principal stored forms

More information

Lecture Series 2 Macromolecules: Their Structure and Function

Lecture Series 2 Macromolecules: Their Structure and Function Lecture Series 2 Macromolecules: Their Structure and Function Reading Assignments Read Chapter 4 (Protein structure & Function) Biological Substances found in Living Tissues The big four in terms of macromolecules

More information

Lecture Series 2 Macromolecules: Their Structure and Function

Lecture Series 2 Macromolecules: Their Structure and Function Lecture Series 2 Macromolecules: Their Structure and Function Reading Assignments Read Chapter 4 (Protein structure & Function) Biological Substances found in Living Tissues The big four in terms of macromolecules

More information

Past Years Questions Chpater 6

Past Years Questions Chpater 6 Past Years Questions Chpater 6 **************************************** 1) Which of the following about enzymes is Incorrect? A) Most enzymes are proteins. B) Enzymes are biological catalysts. C) Enzymes

More information

Biomolecules. Unit 3

Biomolecules. Unit 3 Biomolecules Unit 3 Atoms Elements Compounds Periodic Table What are biomolecules? Monomers vs Polymers Carbohydrates Lipids Proteins Nucleic Acids Minerals Vitamins Enzymes Triglycerides Chemical Reactions

More information

Enzymes: The Catalysts of Life

Enzymes: The Catalysts of Life Chapter 6 Enzymes: The Catalysts of Life Lectures by Kathleen Fitzpatrick Simon Fraser University Activation Energy and the Metastable State Many thermodynamically feasible reactions in a cell that could

More information

RETINOID-PHOSPHOLIPID INTERACTIONS AS STUDIED BY MAGNETIC RESONANCE. Stephen R. Wassail* and William Stillwellt

RETINOID-PHOSPHOLIPID INTERACTIONS AS STUDIED BY MAGNETIC RESONANCE. Stephen R. Wassail* and William Stillwellt Vol.''% No. 3 85 RETINOID-PHOSPHOLIPID INTERACTIONS AS STUDIED BY MAGNETIC RESONANCE Stephen R. Wassail* and William Stillwellt Departments of Physics* and Biology+ Indiana University-Purdue University

More information

Revision Sheet Final Exam Term

Revision Sheet Final Exam Term Revision Sheet Final Exam Term-1 2018-2019 Name: Subject: Chemistry Grade: 12 A, B, C Required Materials: Chapter: 22 Section: 1,2,3,4 (Textbook pg. 669-697) Chapter: 23 Section: 1,2 (Textbook pg. 707-715)

More information

Assignment #1: Biological Molecules & the Chemistry of Life

Assignment #1: Biological Molecules & the Chemistry of Life Assignment #1: Biological Molecules & the Chemistry of Life A. Important Inorganic Molecules Water 1. Explain why water is considered a polar molecule. The partial negative charge of the oxygen and the

More information

SID#: Also give full SID# (w/ 9) on your computer grid sheet (fill in grids under Student Number) BIO 315 Exam I

SID#: Also give full SID# (w/ 9) on your computer grid sheet (fill in grids under Student Number) BIO 315 Exam I SID#: Also give full SID# (w/ 9) on your computer grid sheet (fill in grids under Student Number) BIO 315 Exam I Choose an answer of A,B, C, or D for each of the following Multiple Choice Questions 1-35.

More information

Lecture Series 4 Cellular Membranes

Lecture Series 4 Cellular Membranes Lecture Series 4 Cellular Membranes Reading Assignments Read Chapter 11 Membrane Structure Review Chapter 21 pages 709-717 717 (Animal( Cell Adhesion) Review Chapter 12 Membrane Transport Review Chapter

More information

HPLC '88. Poster Presentation. Isolation of Thymosin B4 from Thymosin Fraction 5 by Reverse Phase HPLC

HPLC '88. Poster Presentation. Isolation of Thymosin B4 from Thymosin Fraction 5 by Reverse Phase HPLC Essentials in HPLC '88 Poster Presentation Isolation of Thymosin B4 from Thymosin Fraction 5 by Reverse Phase HPLC M. Badamchian, M.P. Strickler, M.J. Stone, A.L. Goldstein for Waters.bioresearchThe absolute,

More information

X-ray diffraction study on interdigitated structure of phosphatidylcholines in glycerol

X-ray diffraction study on interdigitated structure of phosphatidylcholines in glycerol X-ray diffraction study on interdigitated structure of phosphatidylcholines in glycerol Hiroshi Takahashi 1,*, Noboru Ohta 2 and Ichiro Hatta 2 1 Department of Physics, Gunma University, 4-2 Aramaki, Maebashi

More information

and controllable behavior - Supplementary Information

and controllable behavior - Supplementary Information Metastability in lipid based particles exhibits temporally deterministic and controllable behavior - Supplementary Information Guy Jacoby, Keren Cohen, Kobi Barkan, Yeshayahu Talmon, Dan Peer, Roy Beck

More information

Lecture Series 4 Cellular Membranes. Reading Assignments. Selective and Semi-permeable Barriers

Lecture Series 4 Cellular Membranes. Reading Assignments. Selective and Semi-permeable Barriers Lecture Series 4 Cellular Membranes Reading Assignments Read Chapter 11 Membrane Structure Review Chapter 12 Membrane Transport Review Chapter 15 regarding Endocytosis and Exocytosis Read Chapter 20 (Cell

More information