Methanosarcin kandleri is an species known for very high growth temperatures. Us
ID: 192708 • Letter: M
Question
Methanosarcin kandleri is an species known for very high growth temperatures. Using your following types of phospholipids would be found in Methanosarcinaceae and Methanopyrus, respectively? aceae spp. are known psychrophiles while Methanopyrus stion yet answered ked out of knowledge gained in class and from the internet, which of the bactera bacteria bacteria Select one: 0 a. Methanosarcinaceae-E only, Methanopyrus-G only b. Methanosarcinaceae -A or E; Methanopyrus - G or H c. Methanosarcinaceae E only; Methanopyrus G or H d. Methanosarcinaceae -G or H; Methanopyrus -E only e. Methanosarcinaceae -C or D; Methanopyrus- A only cross out cross out cross out cross out cross outExplanation / Answer
Answer:
Option B is correct.
Explanation:
Biological membranes are mainly composed of lipids and proteins (protein molecules float in the sea of lipids) and provide selective permeability for various molecules into the cell. They are sheet-like, noncovalent assemblies. The lipid molecules of the membrane prevent the free flow of polar molecules whereas proteins serve as receptors for signaling cascades and components of transport systems. Membrane structure and composition is dynamic i.e., it changes according to the environmental conditions. They are asymmetric and fluid in nature i.e., all the lipids and several proteins can easily diffuse rapidly in the plane of the membrane.
The fluidity of the membrane depends on its chemical composition and temperature. Lipids with longer fatty acid chains have more interactions between the hydrophobic fatty acid tails, stabilizing the crystal-like state and making the membrane less fluid. Saturated fatty acids also strengthen membranes and reduce fluidity.
The shift to the higher temperature would increase the fluidity of the membrane by reducing packing of the hydrophobic chains. To prevent this, new phospholipids would be synthesized having longer chains and less number of double bonds. The longer chains would increase the amount of Vander Waals interactions and absence of double bonds reduces the kink in structure, would enhance packing of the fatty acid tails of the phospholipids.
Incorporation of specific lipids, such as sphingomyelin is known reduce the membrane fluidity. So, its synthesis may go up. Cholesterol acts as a positive as well as a negative regulator of membrane fluidity. At high temperatures, it stabilizes the membrane structure, whereas at low temperatures it intercalates between the phospholipids and prevents them from clustering together.
The presence of cyclic fatty acids decreases membrane fluidity.
Methanosarcinaceae spp. = Psychrophile = Grows in colder habitats
Methanopyrus kandleri = Thermophile = Grows in hotter habitats
Methanosarcinaceae spp. should contain high amounts long, unbranched, and saturated fatty acids in its biological membranes to maintain optimum membrane fluidity.
Methanopyrus kandleri should contain high amounts short, branched, and unsaturated fatty acids in its biological membranes to maintain optimum membrane fluidity.