Exam 23.11.2020

1. What types or categories of protein components are found at membrane contact sites (MCSs)? - Explain the principal modes of action of different types of MCS proteins.

2. Describe the steps and players involved in a generic endocytic event. Rather than naming specific proteins and molecules, describe what is their role in the process.

3. Membrane dynamics is essential for many important cellular processes. Lipid movement within a lipid bilayer and between cellular compartments is highly regulated. Could you explain the details/processes of membrane dynamics and specify the factors that regulate these membrane dynamics?

4. What are the similarities and differences regarding the formation and properties of lipoprotein particles and lipid storage organelles.

5. Group of researchers is studying a transmembrane protein of unknown function. The crystal structure of the protein reveals that it is composed of three alpha helices. When they over-express the wild type protein in cells, they notice that the plasma membrane shape is changed. Describe how this protein impacts membrane shape and what is the underlying mechanism. What experiments could be done to validate that this mechanism?

BONUS QUESTION (6): 6. Describe the methodological principles of the lipidomics study that you would perform in the following two cases:
i) You have wild type and mutant strains of mice in your laboratory and functional studies suggest that the hepatic lipid metabolism of the mice may be somehow different but you do not have any idea in which way or which metabolic pathways may have been affected by the mutated gene. The gene has not been linked to lipid metabolism before.
ii) You have wild type and mutant strains of mice in your laboratory and based on several symptoms of the mutant individuals you have good reasons to assume that in their liver n- 3 polyunsaturated fatty acid (n-3 PUFA) precursors are not enzymatically converted to the biologically most valuable longer chain and more highly unsaturated n-3 PUFAs that would be required for example in membrane phospholipids to support functions of various proteins.