Catalyst: 1. Which of the cells below is the BEST example of what the celery cells in salt water look like? Explain why. 2. What type of cells are our bodies made of? a. Eukaryotic animal cells c. prokaryotic cells b. Eukaryotic plant cellsd. fungi cells 3. _________ are proteins that speed up chemical reactions. a.b. c.

Objective: #1 Describe the cell cycle and the steps of mitosis.

Cell Cycle: The sequence of growth and division of a cell.

During the cell cycle… Cell goes through 2 periods  Growth period  Division period

Growth Period Interphase: period of growth and copying of DNA for the cell, most of a cell’s life is spent in interphase.

Division Period Mitosis: period of nuclear division, 2 daughter cells are formed each containing a complete set of chromosomes What are chromosomes? The carriers of genetic information that are passed from one generation to the next.

Chromosome Structure

Mitosis: 4 phases Prophase Metaphase Anaphase Telophase

Prophase Longest phase of mitosis Visible chromosomes form Nucleus begins to disappear

Metaphase: Chromosomes are pulled by spindle fibers They line up on the midline of the spindle

Anaphase: Centomeres split apart Sister chromatids pulled to opposite poles

Telophase 2 distinct daughter cells formed After telophase,cells separate and cytoplasm is divided in a process called cytokinesis

Objective:#2 Determine how control of the cell cycle is related to the formation of cancer cells.

Normal Cell Cycle Control Proteinsenzymes Proteins and enzymes control the cell cycle. They control the movement from interphase to mitosis.

What would happen if the cell cycle got out of control? Cancer Cancer: a malignant growth of abnormal cells resulting from uncontrolled cell division

Where in the cell cycle do things go wrong? Enzyme genes Enzyme production is directed by genes located on the chromosomes. gene A gene is a segment of DNA that controls protein production.

Where in the cell cycle do things go wrong? (continued) Scientist believe that the portion of interphase just before DNA replication is the key control period in the cell cycle.