NORWEGIAN UNIVERSITY OF SCIENCE AND TECHNOLOGY DEPARTMENT OF BIOTECHNOLOGY Professor Bjørn E. Christensen, Department of Biotechnology

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1 1 NRWEGIAN UNIVERSITY F SCIENCE AND TECNLGY DEPARTMENT F BITECNLGY Prfessr Bjørn E. Christensen, Department f Bitechnlgy Cntact during the exam: phne: , EXAM TBT4135 BIPLYMERS 11 December 2008 Time: Aides: B1. Apprved calculatr with empty memry, accrding t list prvided by NTNU, is permitted. N printed r written dcuments may be used during exam. Please use pen nt pencil! Censring deadline: 11 January 2009 Censring: Relative weights f questins 1: 20% 2: 20% 3: 20% 4: 15% 5: 25%

2 2 1. Mark yur answer directly n the sheet (pen, nt pencil). Clumn 3: Write X (Extra cpy in Appendix 1) Student number.. Mnsaccharide Name (incl. D/L and α,β fr rings) Essential cmpnent (>20%) f a C Cellulse Amylse Dextran Xanthan yalurnan Agarse Chitsan Alginate Neither/Ingen b C Cellulse Amylse Dextran Xanthan yalurnan Agarse Chitsan Alginate Neither/Ingen c Cellulse Amylse Dextran Xanthan 2 C yalurnan Agarse Chitsan Alginate Neither/Ingen d Cellulse C Amylse Dextran Xanthan yalurnan Agarse Chitsan Alginate Pectin Neither/Ingen e Cellulse Amylse C Dextran Xanthan yalurnan Agarse Chitsan Alginate Pectin Neither/Ingen

3 3 f g Carrageenan Amylse Dextran Xanthan yalurnan Agarse Chitsan Alginate Pectin Neither/Ingen Amin acid Name (incl. crrect sterechemistry) Side chain prperty at p 7 Plar, un 2 N C C Nnplar C 3 Negatively Psitively h 2 N C C C Plar, un Nnplar Negatively Psitively i 2 N C C C N 2 Plar, un Nnplar Negatively Psitively j 2 N C C Plar, un Nnplar Negatively Psitively Several alternatives in principle pssible in clumn 3: Crrect answer: +1 Wrng answer: a) Explain the structural (chemical) requirements needed t frm hydrgen bnds (which type f atms, typical distances and bnd angles)? b) Which hydrgen bnds stabilize the α-helix in prteins? c) What is the thermdynamic basis fr the frmatin f hydrgen bnds (such as in α-helices) in aqueus systems? Explain briefly (max 100 wrds)

4 4 d) igh cncentratins (6-8 M) f urea are knwn t denaturate many prteins. Explain briefly the thermdynamic basis fr such denaturatin (max 100 wrds) 3. A linear (unbranched) plysaccharide is subjected t randm degradatin, fr instance by acid hydrlysis. The prcessed is mnitred using a capillary viscmeter by regularly recrding the flw-thrugh-time f the slutin,. Key parameters: c = cncentratin f plysaccharide (g/ml) x = degradatin time (reactin time) (sec) t s = flw-thrugh-time f pure slvent (sec) t x = flw-thrugh-time f plymer slutin at a degradatin time x a) Explain, step-by-step, hw the rate cnstant f the reactin (k) can be determined frm a series f experimental data (t x values btained fr different x values) b) Which fundamental prperties f a plymer/slvent system are expressed by the intrinsic viscsity? c) Why shuld viscsity measurements be perfrmed at relatively lw shear rate when they are used t find the shape and extensin f plymers in slutin? d) If the plysaccharide has a weight average mlecular weight (M w ) f Da at x = 0 min, and Da after 60 min f degradatin, what is M w after 30 min f degradatin? 4. The figure shws results (intrinsic viscsity versus mlecular weight) btained by size-exclusin chrmatgraphy (SEC) with n-line cncentratin detectr, multi-angle light scattering detectr, and viscsity detectr. The tw lines crrespnd t alginate (upper) and hyalurnan (lwer). a) Explain briefly [max 100 wrds and (preferentially) a simple sketch] the principle f plymer separatin in SEC b) n basis f the figure in Appendix 3, determine the expnent in the MS cnstants in the tw cases c) Cmment the results

5 5 5. The figure (data given in Appendix 2) shws results btained by light scattering f a plysaccharide in aqueus slutin: 1.5E E-05 Kc/Rθ c1 c2 5.0E E sin 2 (θ/2) a) n basis f the figure, estimate the mlecular weight and the secnd virial cefficient f the plysaccharide. b) Which average f the mlecular weight is btained if the plysaccharide is plydisperse? c) Define the average in b) in terms f M i and c i. d) Prvide prf fr the mlecular weight average e) Given the biplymer cntains 50% urnic acids, wuld the mlecular weight and/r the secnd virial cefficient change if the inic strength changed (prvided p 7) Explain briefly (max 100 wrds)

6 6 APPENDIX 1 Student number:. Cpy f table in questin 1 Mnsaccharide Name (incl. D/L and α,β fr rings) Essential cmpnent (>20%) f a C Cellulse Amylse Dextran Xanthan yalurnan Agarse Chitsan Alginate Neither/Ingen b C Cellulse Amylse Dextran Xanthan yalurnan Agarse Chitsan Alginate Neither/Ingen c Cellulse Amylse Dextran Xanthan 2 C yalurnan Agarse Chitsan Alginate Neither/Ingen d Cellulse C Amylse Dextran Xanthan yalurnan Agarse Chitsan Alginate Pectin Neither/Ingen e Cellulse Amylse C Dextran Xanthan yalurnan Agarse Chitsan Alginate Pectin Neither/Ingen

7 7 f g Carrageenan Amylse Dextran Xanthan yalurnan Agarse Chitsan Alginate Pectin Neither/Ingen Amin acid Name (incl. crrect sterechemistry) Side chain prperty at p 7 Plar, un 2 N C C Nnplar C 3 Negatively Psitively h 2 N C C C Plar, un Nnplar Negatively Psitively i 2 N C C C N 2 Plar, un Nnplar Negatively Psitively j 2 N C C Plar, un Nnplar Negatively Psitively

8 8 APPENDIX 2 10,000 Alginate (PT-180) yalurnan [η] (ml/g) 1, , ,000 1,000,000 10,000,000 M [Nte: lg 100 = 2, lg 1000 = 3 etc]

9 9 APPENDIX 3 Numerical data used in questin 5 Raw data: (Kc/R θ ) as a functin f c and θ: θ sin 2 (θ/2) c 1 (g/ml) c 2 (g/ml) θ E E-06 θ E E-05 θ E E-05