Cell Cycle Regulation

Determining frequency of divisionCell type (what type of cell is it)

Organism’s stage of development

Current state of organism

Controlling divisionProtein, 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

Checkpoints between G1 & S between G2 & probetween Meta & Ana

If any mistake is noted, cycle stops

ApoptosisProgrammed cell death

Cell shrinks

Releases proteins calling for phagocytes

50-70 billion die each day!!!

When it goes wrong

Cancer

CancerUncontrolled growth and division of cells

Occurs due to mutations, frequently in the CDKs

Cell cycle becomes unregulated

Apoptosis stops

Cells proliferate

Cancer proliferationCancer cells do not remain in interphase

Reproduce more rapidly than normal cells

Outcompete for resources

Choke off normal cells, tissue/organ no longer functions

CausesToxins such as Carcinogens

Put harmful molecules in body that cause mutations

Cells that divide frequently

Repairing what was lost

Stem Cell Research

Stem CellsUnspecified cells that develop into specialized cells

By placing near specialized cells, they will adopt the same specialization

Embryonic Stem CellsAfter fertilization, cells have not specialized

Specialize based on position and intercommunication

Adult Stem CellsPost-development (differentiation has occurred)

Located in different areas of the body (Pancreas, bone marrow, nasal cavity)

Take on function of tissue they enter

DifferencesNobody dies with adult stem cells

Far greater success with adult stem cells

Typically used on the same person who donated