Many features of ------cells make them suitable for biochemical studies of the c
ID: 268960 • Letter: M
Question
Many features of ------cells make them suitable for biochemical studies of the cell-cycle control system. For example, the cells are unusually large and are arrested in a -------- like phase. When the cells are triggered to resume cycling, the cell divisions have especially --------- G1 and G2 phases and occur ---------- . Studies with Xenopus eggs identified a partly purified activity called ------- that drives a resting Xenopus oocyte into M phase. MPF activity was found to be -------- during the cell cycle, although the amount of its kinase component, called ------- , remained constant. The regulatory component of MPF, called -------- , has a stimulatory effect on MPF activity and plays a part in regulating interactions with its ------ . The components of MPF are evolutionarily ------- from yeast to humans, so that the corresponding human genes are to function in yeast.
able hexokinase short
asynchronously inhibitory sperm
Cdk long steady
conserved M stimulatory
cyclin maturation promoting factor
substrate divergent oscillate
synchronously egg PI 3-kinase
ubiquitin fibroblast regulin
unable G1 S
uniform G2
Explanation / Answer
Many features of egg cells make them suitable for biochemical studies of the cell-cycle control system. For example, the cells are unusually large and are arrested in a G2 -like phase. When the cells are triggered to resume cycling, the cell divisions have especially short G1 and G2 phases and occur synchronously.
Studies with Xenopus eggs identified a partly purified activity called maturation promoting factor that drives a resting Xenopus oocyte into M phase. MPF activity was found to oscillate during the cell cycle, although the amount of its kinase component, called Cdk, remained constant. The regulatory component of MPF, called cyclin, has a stimulatory effect on MPF activity and plays a part in regulating interactions with its substrates.
The components of MPF are evolutionarily conserved from yeast to humans, so that the corresponding human genes are able to function in yeast.