CellCycle_2011.notebook

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March 21, 2011

Mar 7­8:16 AM

Aim: What is the life cycle of a cell?

Do Now: What occurs during mitosis?

Homework:Read pp. 223-232Vocabulary: gene, chromosome, chromatid, centromere, cell cycle, interphase, centriolemitosis,cytokinesis, spindle fiber, centrosome

3/7/2011LE 1LE 3

Jan 22­10:59 AM

The Cell CycleG1 Phase, the cell is doing its everyday job, be it as a nerve cell, secreting cell in the stomach or whatever.At this time the each have just one molecule of DNA. Chromosomes with one strand of DNA are called unduplicated or unreplicated chromosomes.S Phase, the DNA replicates or duplicates. The chromosomes that result have two molecules of DNA and are called duplicated or replicated chromosomes.

G2 phase, the cell is carrying out processes necessary for mitosis to begin.

Mitosis. The stage of the cell's life cycle when the cell's DNA gets divided into two separate nucleii.

Cytoplasmic Division: As part of cell division the cytoplasm often is often divided between the daughter cells being produced

This process of cytoplasmic division, sometimes called cytokinesis, is a separate process from divsion of the genetic material in mitosis.

Daughter cells. The result of mitosis plus division of the cytoplasm is typically two genetically identical daughter cells. Both daughter cells are each smaller than the original parent cell and have unduplicated chromosomes.

Jan 22­11:52 AM Jan 22­11:52 AM

Jan 22­11:52 AM

3/7/11LE 1

Jan 22­11:02 AM

CellCycle_2011.notebook

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March 21, 2011

Jan 22­11:04 AM Jan 25­9:31 AM

Aim: How do cells reproduce?

Do Now: In what phase or stage do cells spend most of their time?

Homework Read pp. 223- 226 P.226 # 1, 3, 4,

Jan 25­9:36 AM

Why do Cells Reproduce?

Why more cells:1. Need more cells as a multi- cellular organism grows and develops

2. Repair for damaged tissue

3. Old cells die & need replacement

Why is the size of a cell limited? Larger Cells are more difficult to maintain

Cell Size- cell grows by taking in more nutrients, but exchange is limited by surface area: volume ratio

Cell Maintenance- proteins do the work of cells - more proteins needed as cells get larger - if cells get too big, DNA instructions can't be copied fast enough do to distance within cell

Jan 22­11:52 AM

Jan 25­11:11 AM

Centromere- Region of the chromosome that holds the two sister chromatids together

Chromatid- one of the two strands of a chromosome that become visible during mitosis or meiosis

Chromatin- the substance that composes euk. chromosomes; consists of specific proteins, DNA & a small amt of RNA

Chromosome- in a EUK cell one of the structures in the nucleus that are made up of DNA & protein; in a PROK. cell, the main ring of DNA

Cell Cycle Vocabulary

Jan 25­11:11 AM

Centromere- Region of the chromosome that holds the two sister chromatids together

Chromatid- one of the two strands of a chromosome that become visible during mitosis or meiosis

Chromatin- the substance that composes euk. chromosomes; consists of specific proteins, DNA & a small amt of RNA

Chromosome- in a EUK cell one of the structures in the nucleus that are made up of DNA & protein; in a PROK. cell, the main ring of DNA

CellCycle_2011.notebook

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March 21, 2011

Jan 26­6:55 AM

Aim: What are the stages of mitosis?

Do Now: What is the difference between a chromosome & chromatids?

HomeworkVocabulary: Mitosis, cytokinesis, spindle fiber, microtubule

Read pp.228-232P.232 # 2,3,5

Jan 27­10:41 AM

Aim: Lab- Introduction to the cell cycle

Do Now: Read through the Cell Cycle Lab on your desk

Homework

Complete the Cell Cycle Lab. Please label the parts of the cell. Use colored pencils if you have them

Jan 25­10:59 AM

MitosisDefinition:Nucleus of the cell divides & forms 2 nucleiEach nucleus contains a complete se of chromosomesOccurs in Eukaryotic Cells Stages of Mitosis

Prophase- spindle fibers form -Centrosomes help form the spindles, Centrosomes move to the poles - Nuclear envelope disappearsMetaphase-Chromosomes line up along equator (middle) of cell - spindle fibers connect to centromere of each pair of chromatids to the centrosome at the pole of the cellAnaphase- Spindle fibers shorten - chromatids are pulled apart & to opposite sides of the cellTelophase- nucleus reforms, 1 at each pole, spindle fibers break down & disappear - Chromosomes return to their original uncondensed form

Cytokinesis- cytoplasm increases, cell divides into 2 daughter cells

IPMAT

How to remember Mitosis!

Jan 25­12:08 PM

LE 3 3/7/2011

Jan 27­10:38 AM

Aim: Lab Intro to the cell cycle

Do Now: Read through the lab introduction

Homework: Complete & hand in Lab tomorrow

Jan 25­12:08 PM

CellCycle_2011.notebook

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March 21, 2011

Jan 26­6:54 AM Jan 25­9:44 AM

Practice! Do Now: Complete the phases of mitosis

Jan 25­9:44 AM

Practice! Do Now: Complete the phases of mitosis

Jan 28­8:27 PM

Aim: What regulates cell reproduction?

Do Now: Prepare for a quiz on mitosis.

Homework

Vocabulary: Cancer, tumor, feedbackRead pp. 232- 234P. 234 # 1, 2.3

Jan 29­11:10 AM

Do Now: Copy LE 3 1/29/10

Jan 29­11:06 AM

CellCycle_2011.notebook

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March 21, 2011

Jan 28­10:19 PM

Controls • An injury that requires repair signals cell division• When new cells come in contact with other cells,a negative feedback signal tells the cells to slow down or stop dividing• Proteins & the environment signal the cells

Checkpoints during MitosisFeedback mechanisms at key checkpoints during the cell cycle can delay or trigger the next phase of cell cycle

Checkpoints:G1 -if conditions are healthy cell enters the S phase; if not, cell stays in rest phaseG2 - before mitosis begins, copied DNA checked for mistakes. - Enzymes try to correct any DNA mistakes - Proteins check to make sure cell is large enough to divide - Cell enters mitosis if it passes checkpointMitosis- in metaphase,cell insures that Chromosomes are attached to spindle fibers & checks that genetic material is evenly divided

Jan 28­11:49 PM

cyclin­dependent kinases (CDKs),

Jan 28­11:53 PM Jan 28­10:51 PM

Cancer

Uncontrolled cell growth that can result in masses of cells thatinvade & destroy healthy tissue

A. Causes• being researched• damaged DNA, environmental conditions/ exposures, genetic B. Tumors- masses of cells• Benign- does not spread to other parts of body, treated w/ surgery• Malignant- can spread through body, invading healthy tissue & disrupting cell functions; can be fatal

C. Treatment• Surgery• Chemotherapy- chemicals that kill cells• Radiation therapy- uses radiation beams aimed in precise beams at tumor cellsDNA-damage response (DDR) has evolved to optimise cell survival following DNA damage; it involves the recruitment of DNA repair proteins to sites of damage and the “checkpoint” events that slow down or arrest cell-cycle progression. Importantly, DDR proteins play key roles in preventing cancer, and their activities, in part, determine the outcome of cancer radiotherapy and chemotherapy.Prevention• Avoid exposure to environmental stresses & toxins, UV-A,B rays! wear sunscreen!

Jan 29­12:10 AM Jan 29­12:26 AM

Malignant melanoma. The incidence of this form of skin cancer is increasing faster than that of any other form of cancer.

CellCycle_2011.notebook

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March 21, 2011

Jan 29­12:11 AM

Cervical Cancer (Neoplasma)

This is a squamous cell carcinoma. Note the disorderly growth of the squamous epithelial cells in these large nests with pink keratin in the centers. Neoplasms may retain characteristics of their cell of origin. Benign neoplasms mimic the cell of origin very well, but malignant neoplasms less so.

Benign Tumor of Small Intestine

Jan 29­12:19 AM

This schwannoma was resected from a nerve. This neoplasm arises from the Schwann cells that myelinate peripheral nerve fibers. Note the circumscribed nature of this benign neoplasm. Though benign, this neoplasm could cause dysfunction of the nerve by mass effect.