Biology 1002B Lecture Notes - Lecture 19: Biochemical Cascade, Embryogenesis, Mortality Rate
12 Apr 2017
School
Department
Course
Professor
Document Summary
Programmed cell death had to come from somewhere: for an organism to develop, some of their cells had to die. Produced all the time, but not functional: cells are waiting for signal to be activated to kill themselves. If ced-9 is on, the system is off. Outside of the cell: protein that gets detected from the outside. Maternal effect genes: the first ones to be translated, expressed in the mother, mrnas are put into the egg. Segmentation genes: first to be expressed in the nuclei of zygotes. Transcript can be produced by one organism and expressed in another. Executioner caspases: proteases that cleave specific, essential proteins, controlled but irreversible biochemical cascade causing cell shrinkage, chromatin fragmentation, and cell death. Anti-toxin is degraded more quickly by protease (green) but is replenished. Cells that lose the plasmid are killed by toxin. A daughter that doesn"t have the plasmid will have the toxin but not the anti-toxin, so it will be killed.
