Cell DivisionDifferentiation &

Regulation

All living organisms reproduceAll living organisms grow and developAll living organisms have cellular

organization

Characteristics of life

All living organisms reproduceAll living organisms grow and developAll living organisms have cellular

organization

Characteristics of life

Through dividing process!Bacteria cell division (Binary Fission)Somatic cell division (Mitosis)Gametic cell division (Meiosis)

Where do cells come from?

omnis cellula e cellula

The larger the cell:The more demands on DNA (gene expression)The more difficult homeostasis becomes

(photo/resp)

Why do cells divide?

Prokaryotic CellsDNA is replicatedProteins control when the cell membrane

dividesDaughter cells are identical to parent cells

Process: Binary Fission

Eukaryotic CellsDNA is replicated, packaged, & organized!Proteins control when the cell membrane

dividesDaughter cells are identical to parent cells

Process: Somatic cell division (Mitosis)

Eukaryotic CellsDNA is replicated, packaged, swapped, &

organized!Proteins control when the cell membrane

divides twice!Daughter cells are not identical to parent cells

Process: Gametic cell division (Meiosis)

Process: Somatic Cell Cycle

Life cycle of an individual cell

Cell Cycle

Eukaryotic CellsDNA is replicated, packaged, & organized!Proteins control when the cell membrane

dividesDaughter cells are identical to parent cells

Process: Somatic cell division (Mitosis)

Cellular processes occur normally DNA is packaged around histones into

chromosome

Cell Cycle: G1 phase

DNA is replicated

Cell Cycle: S phase

Cellular processes occur normally DNA is packaged around histones into

chromosome

G2 Phase

DNA is organized Proteins control when the cell membrane

dividesProphase, Metaphase, Anaphase, Telophase,

CytokinesisDaughter cells are identical to parent cells

M phase

Division of one cell reproduces the entire organismAsexual Reproduction (mitosis)

Unicellular Eukaryotes

Division is necessary for growth & repairAsexual Reproduction (mitosis)

Multicellular Eukaryotes

http://highered.mcgraw-hill.com/sites/9834092339/student_view0/chapter10/animation_-_cell_division.html

Cell Division Animations

Cell Differentiation

All humans start as 1 cellAll humans at birth contain

100,000,000,000,000 cells

Embryo Development

Zygote cells are not specialized (stem cells)Baby/Adult cells are specialized (somatic

cells)

Specialization in Cells

Process in which cells become specializedGene expression controls the destiny of each

cell

Cell Differentiation

After differentiation occurs, genes are turned off

Specialized Cells

Build specialized cells/tissues for treatmenthttp://

www.youtube.com/watch?v=j9hEFUpTVPA

Uses of Stem Cells

Cancer

Concentration of Cyclins (protein) build in a cell

Threshold of Cyclins are reached, cell dividesCDK break down Cyclin & levels fall after

mitosis

Regulating cell division

If a cell fails a checkpoints G0 phase

Resting/non-dividing phaseCell undergoes apoptosis

Programmed cell death

Normal unhealthy cells

Abnormal unhealthy cellsIgnore checkpointsAvoid apoptosisExperience a short interphaseForm tumors

TumorsBenign:

Cells are normal but overgrownMalignant:

Cells are abnormal & break awayCells invade other tissues

~230 different types of human cells/cancerIn 2007, 7.9 million people died of cancer

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)

Researching Causes of Cancer

Inside the GenomeOncogenes:

sections of DNA that code for uncontrolled growth

Tumor Suppressor Genes:sections of DNA that code for cancer inhibition

Carcinogens cause mutationOncogenes are turned onTumor suppressing genes are turned off

Mutations

Determine how to stop tumors.Chemotherapy & Radiation

Determine how cells avoid checkpoints.Cyclin & CDK, and other molecules

Determine how genes are turned on/off.

Surviving Cancer

http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter2/animation__control_of_the_cell_cycle.html

Regulating Cell Cycle