Final exam

Eukaryotic cells use growth factor to progress to S phase. Prokaryotes constantly divide unless the environment is poor

G1, S, G2 phases Gap 1, 11hrs, replication proteins and histones created, growth Synthesis, 8hr, Monads are duplicated semiconservatively G2, 4hrs, prepares MTs, myosin, MFs, duplicates centrosome

1 hr long Prophase - chromosomes condense, MTs form, chromosomes begin to separate Prometaphase - Mitotic spindle fibers connect to kinetochores, nuclear envelope and lamina breakdown Metaphase - chromosomes line up at metaphase plate, MTs grow in positive direction, kinesin binds to kinetochore MTs at centromeres of chromosomes Anaphase A - monads move to centrosomes MTOCs, MTs shrink, dynein on KC-MTs, cohesin breakdown Anaphase B - centrosomes move towards PM, astral MTs reel the centrosome with dynein. Polar MTs use kinesin to push the centrosomes apart Telophase - nucleus reforms, chromosomes decondense, MTs disassemble, contractile ring with myosin and MTs forms for cytokinesis.

G1 CP - checks for growth factor, cells without move to G0 instead of S. Checks for large enough cell size, needed proteins, and damaged DNA. S CP - after replication, determines if DNA is damaged, if so then forces cell death G2 CP - checks if cell is large enough, if needed proteins are present, and if DNA is damaged. M CP - between metaphase and anaphase, checks for proper spindle assembly and chromosome alignment, if kinetochores are attached to MTs.

Sends signals in cells to cause replication. Cyclin and collagen are transcribed as a result of their signal. GF–>RTK/GPCR->Ras/Raf/Mek/Erk->nucleus->txn of collagen and cyclin

Cyclin cycles to control the activation of Cyclin-Dependent Kinase CDK. Late in S phase, cyclins begin to rise until M phase entry, activating CDKs. Cyclin levels lower in late mitosis until G1 entry.

Activated when cyclin concentration is high. Concentration of CDK does not change, but is activated as needed. CDK phosphorylates cellular components when activated. CDK phosphorylates the nuclear lamina to cause its breakdown using intermediate filament lamins. Condensin is phosphorylated to tighten chromatin into heterochromatin, condensing chromosomes. MT proteins are phosphorylated to create the mitotic spindle. Golgi Matrix proteins are phosphorylated to fragment the Golgi. Once CDK is inactive, phosphatases are activated, removing phosphate residue. The hydrolysis causes the reversal of CDK processes, like reformation of the nucleus.