Prüfung Biopolymers 11.01.2018
Insgesamt 43 Punkte (ab 22 Punkten positiv)
Sie gibt vor wie lang die Antwort sein soll & will auch nicht mehr haben, meistens nur eine Zeile
1) (1 point per subpoint)
a. What properties of xylan can be detected (-oder irgendein anderes Wort) with Fehlig’s reaget?
b. What kid of reaget is Fehlig’s?
c. What reagent shows the same reaction?
d. Name two other polypers with similar behaviour.
2) What does not fit? Brief description why (2 points) Xylan Cellulose Glucose Alginate Glucose Starch
3) ?
4) a. What PS is this? (0.5 points) (es waren 3 Einheiten mit M – G – M beschriftet)
b. Name the parts & describe the polymer (bonds, residues, etc.). 5 parts are missing (2,5 points)
5) Hyrdocolloids do’t for gels.
a. Gelling mechanisms? (3 Points)
b. Give to one gelling mechanism an example (1 point)
6) False & true statements about Hemicelluloses (8; 0,5points/statement)
7) How is Nanofibrillated cellulose produced? (3 points)
a. What are the challanges?
b. How can this challenges be overcomed?
Chitin & Chitosan - are they water soluble? Which structural & molecular properties are responsible for that?
9) „ priciples of gree cheestry“. What do they state i desiig ew products & processes. Do no give the 12 principles but rather summarize them in 3 sentences. (4 Zeilen zum Antworten) (4 points?)
10) Give the 4 main differances in properties of cellulose & alginate (4 points) Properties Cellulose Alginate
11) Figure of gelenization of Starch in different T-stages: Describe the phenomenon of gelenization of starch. (2 points?)
12) Argue about Nanocellulose as edible food coating (5 Zeilen zum Antworten) (4 points?)

Jänner 2021, mündlich:

1.) Favourite polymer

2.) L-idose in Harworth-formation

3.) Xylan, Cellulose, Stärke, Chitosan - Which doesn't fit

4.) Recognizing and explaining Chitosan

5.) Cellulose - from wood to T-shirt - how, what has to be considered

Exam 08.02.2023

1) Alginate - 5 true or false statements
2) Chitin, Hemicellulose, Cellulose, Starch - which does not fit and why
3) Describe how the following derivates are produced - what is the starting material? Cellulose acetate, Cellulose Nanocrystals, Cellulose microfibrils
4) Draw L-Glucose (given in Fisher) in Haworth projection - as beta-pyranose
5) What do all PS have in common compared to other (bio)polymers? What is the driving force whether a PS is soluble in water or not? Name 2 water-soluble and two water-insoluble PS or derivates
6) What happens when methyl cellulose is heated? Describe the process from heating to cooling
7) "All plant-based substances are biodegradable" - discuss if this statement is true or false
8) Structure of Lignin was given - recognize the biopolymer, where does it come from and how can you isolate it, what are the special properties
9) Starch - name the two building blocks, how do they differ concerning molar mass (degree of polymerization) and alpha 1-6 ... or something like that
10) Name two pulping processes. Lignin --> why is it not that applicable from a chemical point of view
11) 4 differences between Chitosan and Cellulose