Cellular Biology: Cycles, Regulation, & Differentiation AP Biology Ch. 12

Life is cellular

Multicellular Development

Cellular Life Cells form: Cells divide: Cells die: 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

Process: Binary Fission Prokaryotic Cells DNA is replicated Proteins control when the cell membrane divides Daughter cells are identical to parent cells

Process: Somatic cell division (Mitosis) Eukaryotic Cells DNA is replicated, packaged, & organized! Proteins control when the cell membrane divides Daughter cells are identical to parent cells

Process: Gametic cell division (Meiosis) Eukaryotic Cells DNA is replicated, packaged, swapped, & organized! Proteins control when the cell membrane divides twice! Daughter cells are not identical to parent cells

General Cell Cycle Continuous sequence of events Starts with one cell (parent) Ends with two identical cells (daughter)

Copy the Genome 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

DNA Packaging Human Chromosomes

Cell Cycle

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

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

S phase Synthesis Phase DNA is replicated SUPA IMPORTANTE!

G2 Phase Second Gap Phase Cell Grows Cell manufactures proteins Organelles are produced Final preparations for division

Interphase G1 S G2

M phase Mitosis Cytokinesis Shortest phase of the cell cycle Results in two identical daughter cells Prophase Metaphase Anaphase Telophase Cytokinesis Cell divides

Regulation

Molecular Regulation: Cell Cycle Cell cycle is controlled by chemical checkpoints Enzymes: cyclin dependent kinases Substrates: proteins called cyclins G1 checkpoint M checkpoint G2 checkpoint

Normal cell division Concentration of Cyclins build in a cell Threshold of Cyclins are reached, cell divides CDK break down Cyclin & levels fall after mitosis

Normal unhealthy cells 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

Apoptosis STP

Unhealthy Cell Division Cells ignore checkpoints Cells avoid apoptosis Cells experience short interphase Results in tumor May Develop into cancer

Cancer ~230 different types of human cells/cancer

Tumors Benign: Malignant: Cells are normal but overgrown Cells are abnormal & break away Cells invade other tissues

Researching Causes of Cancer 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)

Inside the Genome Oncogenes: Tumor Suppressor Genes: sections of DNA that code for uncontrolled growth Tumor Suppressor Genes: sections of DNA that code for cancer inhibition

Mutations Carcinogen causes a mutation Oncogenes are turned on Tumor suppressing genes are turned off

Surviving Cancer Determine how to stop tumors. Chemotherapy & Radiation Determine how cells avoid checkpoints. Cyclin & CDK, and other molecules Determine how genes are turned on/off.

Karyotypes

Review: Somatic cell division (Mitosis) Eukaryotic Cells DNA is replicated, packaged, & organized! Proteins control when the cell membrane divides Daughter cells are identical to parent cells

Process: Gametic cell division (Meiosis) Eukaryotic Cells DNA is replicated, packaged, swapped, & organized! Proteins control when the cell membrane divides twice! Daughter cells are not identical to parent cells

Karyotypes 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

Wolf Karyotype

Goldfish Karyotype

Making a karyotype 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

Analyzing a karyotype What information does a karyotype show? Total number of chromosomes The gender of the individual Chromosomal mutations (genetic diseases)

Henrietta Lacks