Biotechnology
15 ECTS
Ladokcode: A01TAI
The exam is given to: ExamCode:
Date of exam: 2018- 06-01
Time: 14:00-18:00
Means of assistance:
Tillåtna hjälpmedel är lexikon. Dock EJ elektroniskt lexikon It is possible to use dictionary but not in electrical form
Total amount of point on exam: 104p
Requirements for grading: F: <42; Fx: 42 – 50; E: 51 – 59; D: 60 – 69; C: 69 – 77; B: 78 – 86; A: 87 – 104
Additional information: You can give your answers either in English or in Swedish
Next re-exam date:
The marking period is, for the most part, 15 working days, plus up to 5 working days for administration, otherwise it’s the following date:
Important! Do not forget to write the ExamCode on each paper you hand in. Good Luck!
Examiner: Phone number:
Quiz questions: Each correct answer will give you 1 points:
1) In bacterial cells, ribosomes are packed into the cytoplasmic matrix and also loosely attached to the plasma membrane. What is the function of ribosomes?
a) site of energy production b) site of protein synthesis c) site of genetic reproduction
2) Plasmids are important to the genetics of many bacteria. This is because a) they are inherited from one generation to the next.
b) they may carry genes that give their host a selective advantage. c) they can render bacteria drug-resistant.
d) All of the above 3) Gram positive cells
a) have a second, outer membrane that helps retain the crystal violet stain b) have a multiple layers of peptidoglycan that help retain the crystal violet stain c) have a thick capsule that traps the crystal violet stain
d) have a periplasmic space that traps the crystal violet
4) Gram positive cells
a) have a second, outer membrane that helps retain the crystal violet stain b) have a multiple layers of peptidoglycan that help retain the crystal violet stain c) have a thick capsule that traps the crystal violet stain
d) have a periplasmic space that traps the crystal violet 5) Which is least likely to kill bacteria?
a) extreme alkalinity b) extreme heat c) extreme cold d) extreme acidity
6) Unlike saturated fatty acids, unsaturated fatty acids also contain what kind of bonds between carbon atoms
a) double b) triple c) hydrogen d) hydrophobic
7) The prokaryotic transport system that involves a substrate-binding protein, a membrane transporter, and ATP-hydrolyzing proteins is called:
a) The ABC-system b) Group translocation c) Symport
8) Why the substrate concentration does not increase the rate of reaction after a certain point (as shown in the graph below)?
a) All of the of the enzymes are occupied by substrates b) All of the enzymes have been denatured
c) Both are correct
d) None of a) and b) is correct
9) This can be found in what type of biomacromolecule?
a) Lipid b) Protein c) Carbohydrate d) Nucleic acid
10) LPS is an endotoxin that is found on the outer membrane of gram negative bacteria. LPS stands for…….
a) lagging poison stand b) leading poison stand c) lipopolysaccharide d) lactopeptosucrose
Please, answer each of the following questions on a new sheet of paper
Background for questions 11-15
You are planning to produce large quantities of the two compounds ethanol and isoprenoid using two separate bioreactors. You have chosen S. cerevisiae and E. coli as your producers. You know from former studies that ethanol is a primary product and in the literature you have found that isoprenoid is a secondary product.
Question 11
a) Describe the two different producers in terms of: bacteria, fungi, prokaryotic, eukaryotic, Gram negative, Gram positive. (5p)
b) Describe the overall chromosome structure for the two organisms. (6p) c) Describe how the genes are organized in their genome. (6p)
Question 12
Explain what the expressions “primary product” and “secondary product” mean? (4p) Question 13
You have decided to produce ethanol using one of the above mentioned organisms and isoprenoid using the other.
a) Which organism would you chose for production of ethanol and isoprenoid, respectively. Motivate your answer! (8p)
b) Explain what type of culture (batch or continuous) you would need for the production of alcohol and isoprenoid, respectively. Give motive for your choice. (6p)
c) Draw the growth curves and the product formation curve for the two different cultivations in their respective bioreactor and explain what happens during the different phases. (12p)
Question 14
You have heard that genes can be transferred from one organism to another with the help of cloning vectors, so you are planning to try to engineer one of your organisms to see if you can increase their product formation.
a) Describe the important properties for a cloning vector (4p)
b) Describe how a gene is transferred from one organism to another with the help of a vector (6p) Question 15
There are different physical methods for sterilization. Describe three of these methods and give one example for each method when it can be used. (6p)
Questions 16
The fermentative Thermoanaerobacterium thermosaccharolyticum is a good hydrogen producing microorganism, which carries out the hydrolysis and acetogenesis of lignocellulosic materials by forming products like acetate and butyrate.
Cellulase is not one enzyme but a system of exoenzymes with β-Glucosidase as an important component. In T. thermosaccharolyticum this enzyme is encoded by the bgl gene and expressed as a protein with 443 amino acids. Also some mutated strains of E. coli are able to utilize glucosides and here the glucosidase enzyme is encoded by the bgl operon which comprises the three genes,
bglG, bglF, and bglB.
a) What is an exoenzyme? (2p)
b) Draw a sketch over the bgl operon in E. coli. (5p)
c) On the basis of what you have learn about operons, explain the assumed regulation of the bgl operon in E. coli. Give motive for your answer! (8p)
d) Explain the transcription process and its end product. (6p) Question 17
Two reasons, why the highly aerobic A. niger and the facultative anaerobic E. coli are good organisms for industrial production, are the facts that they are unicellular and can be grown on cheap media. As producers, they must be able to create energy. Which of these organisms can survive in oxygen free conditions? Describe the energy producing metabolism during aerobic and anaerobic conditions, respectively. (10p)
