Cell Cycle Regulation
Determining frequency of division Cell type (what type of cell is it) Organism’s stage of development Current state of organism
Controlling division Protein, enzyme interactions Cell environment
Cyclin ~Proteins~ Produced during different stages of cell cycle Bind with enzymes
Cyclin-dependent Kinase Cyclin binds with them This binding allows cell cycle to progress **Evolutionarily conserved**
Enzyme-Protein interaction Different interactions control different stages of the cycle
Checkpoints between G 1 & S between G 2 & pro between Meta & Ana If any mistake is noted, cycle stops
Apoptosis Programmed cell death Cell shrinks Releases proteins calling for phagocytes billion die each day!!!
When it goes wrong Cancer
Uncontrolled growth and division of cells Occurs due to mutations, frequently in the CDKs Cell cycle becomes unregulated Apoptosis stops Cells proliferate
Cancer proliferation Cancer cells do not remain in interphase Reproduce more rapidly than normal cells Outcompete for resources Choke off normal cells, tissue/organ no longer functions
Causes Toxins such as Carcinogens Put harmful molecules in body that cause mutations Cells that divide frequently
Repairing what was lost Stem Cell Research
Stem Cells Unspecified cells that develop into specialized cells By placing near specialized cells, they will adopt the same specialization
Embryonic Stem Cells After fertilization, cells have not specialized Specialize based on position and intercommunication
Adult Stem Cells Post-development (differentiation has occurred) Located in different areas of the body (Pancreas, bone marrow, nasal cavity) Take on function of tissue they enter
Differences Nobody dies with adult stem cells Far greater success with adult stem cells Typically used on the same person who donated