Transcript 5:1 Cell Cycle

5.1 The Cell Cycle
KEY CONCEPT
Cells have distinct phases of growth, reproduction,
and normal functions.
5.1 The Cell Cycle
5.1 The Cell Cycle
More prefixes• Stage-step or part of
mere-segment or part
• Phase-appearance
Soma-body
• Divide-to separate
Centro-center
• Duplicate-an identical copy
• Double-to increase twofold Condense-reduce volume
• Copy-reproduction from an original
• Kine-movement
• inter-between
• pro-before
• meta-middle
• Ana-back
• telo-end
Cells double their DNA in order to divide and create two nearly identical
duplicates or copies.”
5.1 The Cell Cycle
A. Interphase-cell growth
• Gap1 (G1)-rapid protein synthesis, lots of enzyme
activity, organelles replicate (copy)
• Synthesis (S)-chromosomes become visible, replicate
and are now called sister chromatids connected by the
centromeres.
• Gap 2 (G2)-more metabolic activity, centrioles duplicate
and form spindle fibers made of microtubules.
5.1 The Cell Cycle
• The main stages of the cell cycle are gap 1, synthesis, gap
2, and mitosis.
– 1.Gap 1 (G1):2. cell growth
and normal functions
– 3.DNA synthesis (S):
4.copies DNA
– 5.Gap 2 (G2): 6.additional
growth 8. cell/nuclear
division
– 7. Mitotic Phase: includes
division of the cell nucleus
(mitosis) and division of the cell
cytoplasm 13.cytokinesis 14.
Mitosis 15. Cell cycle
5.1 The Cell Cycle
Cells divide at different rates
• G1-varies the greatest
• G0 – this cell is unlikely to divide again
5.1 The Cell Cycle
Cells divide at different rates.
• The rate of cell division varies with the need for those
types of cells.
• Some cells are unlikely to divide (G0).
5.1 The Cell Cycle
• Cell size is limited
• If cell is too small the cell does not contain all the
organelles it needs.
• If a cell is too large-needed nutrients could not diffuse in
and waste could not diffuse out. (starve or poison itself)
5.1 The Cell Cycle
Cell size is limited.
• Volume increases faster than surface area.
5.1 The Cell Cycle
• Surface area must allow for adequate
exchange of materials.
– Cell growth is coordinated with
division.
– Cells that must be large have
unique shapes.