The driving force for the movement of lithosphere plates is convection currents. These currents are found in the inner core of the earth and take the heat from the core to the lithosphere. Tectonic plates are able to move because of the relative density of oceanic lithosphere and the relative weakness of the asthenosphere. Dissipation of heat from the mantle is acknowledged to be the original source of energy driving plate tectonics. The current view, although it is still a matter of some debate, is that excess density of the oceanic lithosphere sinking in subduction zones is the most powerful source of plate motion.
DNAase is an enzyme that catalyzes the hydrolysis of the covalent bonds that join nucleotides together. What would first happen to DNA molecules treated with DNAase?
A) The purines would be separated from the deoxyribose sugars.
B) The pyrimidines would be separated from the deoxyribose sugars.
C) All bases would be separated from the deoxyribose sugars.
D) The two strands of the double helix would separate.
E) The phosphodiester bonds between deoxyribose sugars would be broken.
Answer:
E) The phosphodiester bonds between deoxyribose sugars would be broken.
Explanation:
The purines and pyrimidines of two DNA strands of a DNA duplex are held together by hydrogen bonds. Hydrogen bonds are not covalent bonds. The enzyme DNAase targets the phosphodiester bonds. These are the covalent bonds that join two deoxyribonucleotides of a DNA strand together. therefore, when a DNA is subjected to digestion with DNAase enzyme, the phosphodiester bonds will be broken that hold the pentose sugars of two nucleotides by a phosphate group.
When you wake up a sleep walker, they will be startled, and can have an outburst.
