Can somebody explain these to me? 1.) Explain the setup and results of the famou
ID: 55500 • Letter: C
Question
Can somebody explain these to me?
1.) Explain the setup and results of the famous “heterokaryon experiment” of 1970 and what it taught us about cellular membranes.
2.) If all you know about a protein is its primary structure (amino acid sequence), how might you able to predict if it is a transmembrane protein or not?
3.) All cells are constantly pumping ions out of them. (Yes, some ions are pumped in, but the net movement of ions is outward.) If this pumping stops, the cells quickly explode. Why?
4.) A key step in the activation of both Protein Kinase B and Protein Kinase C is a certain membrane phospholipid. Describe the steps from that molecule common to both pathways to the activation of PKB and PKC.
Explanation / Answer
2)
If a primary structure of protein is a transmembrane protein, then it should have initial and final segments polar amino acids and the middle section with non-polar amino acids. Protein region, which embed inside the membrane is called transmembrane region. The transmembrane regions of many membrane-bound proteins are alpha-helices, because they have hydrophobic amino acids. All the hydrophobic amino acid containing regions in the protein adopt stable -helical structure. And avoid touch with aqueous medium based on their hydrophobicity index, they arrange in a stable pattern and inserted into membrane, which ultimately gives, stability to the membrane protein.
3)
If the pumping of ions is stopped, then cells quickly explode due to generation of the osmotic imbalance.