The Cell Cycle Biology Ch 10 1 10

The Cell Cycle Biology Ch 10 -1 & 10 -2

All cells come from living cells n Cells reproduce: To grow n To replace old/injured cells n To increase the SA: V ratio n

Cell Cycle n A continuous series of events: Starts with one cell n Ends with two identical daughter cells n

Unicellular Organisms n Division of one cell reproduces the entire organism

Multicellular Organisms n Division is necessary for growth and repair

Remember… n Each of your cells has a complete copy of DNA

Genetic Blueprint for Life DNA Genetic Information in a Double Helix Chromatin DNA wrapped around a protein (histone) Not visible! Chromosome Chromatin condensed into a super coil Visible! Chromatid One half of the Chromosome

DNA CHROMATIN CHROMATID CHROMOSOME PROTEIN

Back to the Cell Cycle G 1 MITOTIC (M) PHASE S (DNA synthesis) G 2

G 1 phase - Interphase n First Gap Phase Cell Grows n DNA manufactures proteins n Organelles are produced n

S phase - Interphase n Synthesis Phase DNA is replicated n The longest phase n

G 2 Phase - Interphase n Second Gap Phase Cell Grows n Organelles are produced n Final preparations for division n

LE 12 -5 INTERPHASE S G 1 MIT M OTI CP HA SE G 2

M phase n Mitotic Phase Shortest phase of the cell cycle n Results in two identical daughter cells n Prophase n Metaphase n Anaphase n Telophase n Cytokinesis? n

G 1 checkpoint Control system G 1 M M checkpoint G 2 S

Cell Cycle Checkpoints • Controlled by cyclin: • • Enzymes: Cdk Substrates: Cyclin (protein)