So how do microbes cause B cells and T cells to grow and divide? Each cell has a receptor on its cell surface that recognizes a specific part of a microbe. That receptor triggers a Signal transduction pathway. This triggers gene expression (transcription) that… …leads to protein synthesis (translation) that… …allows the cell to grow (duplicate all its proteins that help to duplicate all its organelles) and divide (mitosis). On to the Cell cycle! Watch this movie to link transcription and translation to the cell cycle: w- hill.com/sites/ x/student_view0/c hapter9/stimulation_o f_cell_replication.html
Cell Reproduction Check this out!! Breast cancer cells dividing: 3rCUODqg&NR=1&feature=fvwphttp:// 3rCUODqg&NR=1&feature=fvwp
The Cell Cycle –Eukaryotic cells that grow and divide undergo an orderly sequence of events called the cell cycle. – The cell cycle consists of two distinct phases: Interphase –Cell growth –Sub-phases: »G1 »S phase »G2 Mitotic phase –Cell division hill.com/sites/ x/student_view0/chapter9/how_t he_cell_cycle_works.html
–OK, we’ve talked about how to transcribe and translate one gene found on the DNA in our nuclei into a functioning protein. But we have more than just one gene…. –Almost all of the genes of a eukaryotic cell Are located on chromosomes in the cell nucleus. From One gene to 25,000 genes
Transcription and Translation occur all throughout Interphase: when the cell is growing and duplicating all of its cell structures and organelles!!
Eukaryotic Chromosomes –Each eukaryotic chromosome contains one very long DNA molecule, Typically bearing thousands of genes. –The number of chromosomes in a eukaryotic cell Depends on the species.
–Detailed representations of DNA Notice that the bases pair in a complementary fashion.
DNA Replication –When a cell or whole organism reproduces, a complete set of genetic instructions must pass from one generation to the next. –This happens during S phase
Figure 10.8
The Cell Cycle –Eukaryotic cells that grow and divide undergo an orderly sequence of events called the cell cycle. – The cell cycle consists of two distinct phases: Interphase –Cell growth –Sub-phases: »G1 »S phase »G2 Mitotic phase –Cell division
Mitosis and Cytokinesis –Mitosis Is the division of the chromosomes. Is preceded by interphase. From movie folder play: - AnimalMitosis_SV.mpgAnimalMitosis_SV.mpg
–Chromosomes Are made of chromatin, a combination of DNA and protein molecules. Are not visible in a cell until cell division occurs.
–The DNA in a cell is packed into an elaborate, multilevel system of coiling and folding.
–Before a cell divides, it duplicates all of its chromosomes, resulting in two copies called sister chromatids. –When the cell divides, the sister chromatids separate from each other. G2 phase G1 phase S phase M phase
Figure 8.8.1
–Mitosis consists of four distinct phases: Prophase Metaphase Anaphase Telophase
Figure 8.8.2
Mitosis recap: dan/Biology160_Fa12/movies/mitosi s_movies/08_06bMitosisOverview_ A.html
–Cytokinesis Typically occurs during telophase. Is the division of the cytoplasm. Is different in plant and animal cells.
Figure 8.9b 41F&playnext=1&index=39
Cancer Cells: Growing Out of Control –Normal plant and animal cells have a cell cycle control system. –Cancer is a disease of the cell cycle. –Cancer cells do not respond normally to the cell cycle control system. Dqg&NR=1&feature=fvwp
–Cancer cells can form tumors, Abnormally growing masses of body cells. –If a tumor is malignant, It can spread to other parts of the body.
Cancer Treatment –Cancer treatment can involve Radiation therapy, which damages DNA and disrupts cell division. Chemotherapy, which uses drugs that disrupt cell division. Turn and talk: How would damaging the DNA of a cell disrupt cell division?
–Cancer cells are often grown in culture for study.
Cancer Prevention and Survival –Cancer prevention includes changes in lifestyle: Not smoking Exercising adequately Avoiding exposure to the sun Eating a high-fiber, low-fat diet Visiting the doctor regularly Performing regular self-examinations