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

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

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

Unicellular Organisms Division of one cell reproduces the entire organism

Multicellular Organisms Division is necessary for growth and repair

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

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

CHROMOSOME PROTEIN DNA CHROMATID CHROMATIN

Back to the Cell Cycle S (DNA synthesis) G1 MITOTIC (M) PHASE G2

G1 phase - Interphase First Gap Phase Cell Grows DNA manufactures proteins Organelles are produced

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

G2 Phase - Interphase Second Gap Phase Cell Grows Organelles are produced Final preparations for division

LE 12-5 INTERPHASE S G1 M G2 MITOTIC PHASE

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

G1 checkpoint Control system S G1 G2 M M checkpoint G2 checkpoint

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