Transcript Cell Cycle Mitosis

AP Biology
Ch. 12
• Cells form:
• Phospholipids
“Omnis cellula e cellua”
• Cells divide:
• New unicellular organisms
• Bacteria, archaea, protists
• Multicellular organisms grow
• Animals, plants
• Increase SA:V
• Cells die:
• Undergo apoptosis
 Prokaryotic Cells
 DNA is replicated
 Proteins control when the cell membrane divides
 Daughter cells are identical to parent cells
 Eukaryotic Cells
 DNA is replicated, packaged, & organized!
 Proteins control when the cell membrane divides
 Daughter cells are identical to parent cells
 Eukaryotic Cells
 DNA is replicated, packaged, swapped, & organized!
 Proteins control when the cell membrane divides twice!
 Daughter cells are not identical to parent cells
 Continuous sequence of events
 Starts with one cell (parent)
 Ends with two identical cells (daughter)
 Every cell in an organism has a copy of the original DNA
 Adult Human:
 ~100,000,000,000,000 cells
 2 Sets of 23 chromosomes ~3 m of DNA
 Human Chromosomes
G1
MITOTIC
(M) PHASE
S
(DNA synthesis)
G2
 First Gap Phase
 Cell Grows
 DNA manufactures proteins
 Organelles are produced
 Synthesis Phase
 DNA is replicated
 SUPA IMPORTANTE!
 Second Gap Phase
 Cell Grows
 Cell manufactures proteins
 Organelles are produced
 Final preparations for division
 G1
 S
 G2
 Mitosis
 Shortest phase of the cell cycle
 Results in two identical daughter cells
 Prophase
 Metaphase
 Anaphase
 Telophase
 Cytokinesis
 Cell divides
 Cell cycle is controlled by chemical checkpoints
 Enzymes: cyclin dependent kinases
 Substrates: proteins called cyclins
G1 checkpoint
M checkpoint
G2 checkpoint
 Concentration of Cyclins build in a cell
 Threshold of Cyclins are reached, cell divides
 CDK break down Cyclin & levels fall after mitosis
 If a cell fails a checkpoints
 Ex: cyclin, DNA, or size problems
 G0 phase
 Resting/non-dividing phase
 Cell undergoes apoptosis
 Programmed cell death
 Controlled by STP
 Cells ignore checkpoints
 Cells avoid apoptosis
 Cells experience short interphase
 Results in tumor
 May Develop into cancer
 ~230 different types of human cells/cancer
 Benign:
 Cells are normal but overgrown
 Malignant:
 Cells are abnormal & break away
 Cells invade other tissues
 What causes cancer cells to form?
 Environment:
 UV radiation (sun), natural chemicals (benzene)
 Diet (obesity), Drugs (cigarettes & alcohol)
 Genetics?
 HBOC Syndrome
 Infection?
 Viruses (Human Papilloma, Epstein Barr)
 Oncogenes:
 sections of DNA that code for uncontrolled growth
 Tumor Suppressor Genes:
 sections of DNA that code for cancer inhibition
 Carcinogen causes a mutation
 Oncogenes are turned on
 Tumor suppressing genes are turned off
 Determine how to stop tumors.
 Chemotherapy & Radiation
 Determine how cells avoid checkpoints.
 Cyclin & CDK, and other molecules
 Determine how genes are turned on/off.
 Eukaryotic Cells
 DNA is replicated, packaged, & organized!
 Proteins control when the cell membrane divides
 Daughter cells are identical to parent cells
 Eukaryotic Cells
 DNA is replicated, packaged, swapped, & organized!
 Proteins control when the cell membrane divides twice!
 Daughter cells are not identical to parent cells
 A picture of an organisms complete set of
chromosomes
 A human karyotype contains:
 46 total chromosomes (23 homologous pairs)
 Chromosome pairs #1-22: Autosomes
 chromosome pair #23: Sex chromosomes
 White blood cells in mitosis are stained and
photographed
 Homologous pairs of chromosomes are placed
together
 Determine homologues?
 Size of chromosomes
 Position of the centromere
 Banding pattern of chromosomes
 What information does a karyotype show?
1. Total number of chromosomes
2. The gender of the individual
3. Chromosomal mutations (genetic diseases)