Cellular Growth Chapter 9

Do Now 1. How big is a cell? 2. What happens if a cell gets too big?

DO NOW Create a model of what happens when you get a cut. Use picture, words, symbols, etc. Be ready to present.

Objectives 1. SWBAT review what happens when you get a cut. 2. SWBAT calculate surface area to volume ratio and relate it to the cell. 3. SWBAT draw and label the cell cycle. 4. SWBAT create 4 sample cells and calculate out their surface area to volume ratio and answer questions on it

9.1 Cellular Growth Ratio of Surface Area to Volume Area Volume

Equations Surface Area: (2 x L x W) + (2 x L x H) + (2 x H x W) Area: L x W x H

Cell Size Limitations Key factor that limits cell growth is ratio of surface area to volume As the cell grows, its volume increases much more rapidly than the surface area. Cell can have difficulty supplying nutrients and expelling waste products.

Transport of Substances Plasma Membrane: Substances move by diffusion or by motor proteins. Diffusion over large distances is slow and inefficient. Small cells maintain more efficient transport systems.

Think – Pair - Share If you had three cells: 3 X 2 X 2 6 x 1 X 1 3 X 6 X 1 Which cell has the largest surface area to volume ratio? What benefit does this cell have?

Cellular Communications The need for signaling proteins to move throughout the cell also limits cell size. Cell size affects the ability of the cell to communicate instructions for cellular functions.

DO NOW Surface area : Volume :: _________ : _______ (Cell Parts) Which cell has a bigger surface area to volume ratio? 2 x 3 x 2 OR 4 x 1 x 1 What benefit does this cell have?

The Cell Cycle Cell division prevents the cell from becoming too large. It also is the way the cell reproduces so that you grow and heal certain injuries. Cells reproduce by a cycle of growing and dividing called the cell cycle

Cell Cycle Varies between 8 minutes and one year Average 12-24 hours

Cell Cycle 1. Interphase (G1, S, G2) 2. Mitosis & Cytokinesis – Cell division

Do Now 1. Which stage of the cell cycle takes the longest time? 2. Which stage of mitosis takes the longest time? 3. Which stage of mitosis takes the least amount of time?

Interphase A. G1 Phase: B. S Phase: C. G2 Phase: First growth phase The cell is growing, carrying out normal cell functions, and preparing to replicate DNA. B. S Phase: DNA is copied (DNA Replication) C. G2 Phase: Second Growth Phase Proteins needed for cell division are produced The cell prepares for the division of its nucleus.

Do Now List three reasons why a cell divides.

Mitosis and Cytokinesis Mitosis: Nuclear Division Cytokinesis: Cell Division

9.2 Mitotic Phase (Cell Division) A. Prophase B. Metaphase C. Anaphase D. Telophase

Label and order the cells from 1 – 5 What are the differences between plant and animal cells during division?

http://www.cellsalive.com/mitosis.htm

Chromosomes

Objectives 1. SWBAT draw and label the stages of mitosis. 2. SWBAT draw and label a chromosome. 3. SWBAT practice labeling diagrams of mitosis in partners.

Chromosomes Chromosome- Chromatid- Chromatin- Centromere- Centriole- Tightly coiled DNA Chromatid- Half a replicated Chromosome Chromatin- loosely coiled DNA Centromere- Center of a chromosome- where the sister chromatids attach Centriole- Organize the microtubules Attach to the spindle fibers

Do Now – Label the Cell Cycle

Prophase The cell’s chromatin tightens Sister chromatids are attached at the centromere. Spindle fibers form in the cytoplasm. The nuclear envelope seems to disappear. Spindle fibers attach to the sister chromatids.

Metaphase Sister chromatids are pulled along the spindle apparatus toward the center of the cell. They line up in the middle of the cell.

Anaphase The microtubules of the spindle apparatus begin to shorten. The sister chromatids separate. The chromosomes move toward the poles of the cell.

Telophase The chromosomes arrive at the poles and begin to relax. Two new nuclear membranes begin to form and the nucleoli reappear. The spindle apparatus disassembles.

Cytokinesis In animal cells, microfilaments constrict, or pinch, the cytoplasm. In plant cells, a new structure, called a cell plate, forms.

Let’s review mitosis… http://highered.mcgraw-hill.com/sites/0072437316/student_view0/chapter11/animations.html

Think-pair-share Try to label the parts of cell division.

Do Now – Label the Cell Cycle

Objectives 1. SWBAT identify cells in prophase, metaphase, anaphase, telophase, and cytokinesis 2. SWBAT calculate the percent of time each cell spends in each phase.

Do Now Label the parts of the cell. What phases of mitosis?

Objectives 1. 1. SWBAT brainstorm why cells have check points. 2. SWBAT create a list of their preconceptions about cancer. 3. SWBAT discuss treatments, causes, and cancer. 4. SWBAT compare and contrast the types of stem cells and apply how they can be useful in science.

9.3 Cell Cycle Regulation Normal Cell Cycle: Different cyclin / CDK (cyclin dependent kinases) combinations signal other activities These including DNA replication Protein synthesis Nuclear division

Quality Control Checkpoints The cell cycle has built-in checkpoints These monitor the cycle and can stop it if something goes wrong. Spindle checkpoints also have been identified in mitosis. Ex. If not spindle fibers – will stop before cytokinesis

What can happen if there was a mutation in the cell cycle?

Write down 5 things you know about cancer. http://www.who.int/features/factfiles/cancer/01_en.html

Abnormal Cell Cycle: Cancer Cancer is the uncontrolled growth and division of cells. Cancer cells can kill an organism by crowding out normal cells, resulting in the loss of tissue function.

Causes of Cancer Changes that alter growth and division of cells are due to mutations. Changes in DNA lead to changes in ____________. Carcinogen is a substance or agent that is known to cause cancer

Types of Carcinogens Tobacco Radiation (UV and X Rays) Asbestos FDA regulates what you eat and drink is safe and makes sure there are warning on carcinogen products

Do Now Explain the purpose of spindle checkpoints in the cell.

Objectives 1. SWBAT define apoptosis and stem cells. 2. SWBAT identify cells in prophase, metaphase, anaphase, telophase, and cytokinesis 3. SWBAT calculate the percent of time each cell spends in each phase.

Cancer Genetics Multiple changes in DNA are needed to cause cancer Cancer increase with age Certain cancers are inherited in certain families (chances to have it)

Apoptosis Programmed cell death Cells going through apoptosis actually shrink and shrivel in a controlled process. Ex. Leave in Fall Ex. Webbed Fingers/Toes DNA Damaged Cells http://www.youtube.com/watch?v=qjjHKDn12qI

Stem Cells Unspecialized cells that can develop into specialized cells when under the right conditions

Stem Cells (Cont.) Embryonic Stem Cells Adult Stem Cells After fertilization, the resulting mass of cells divides repeatedly until there are about 100–150 cells. Found in various tissues in the body and might be used to maintain and repair the same kind of tissue These cells have not become specialized. Less controversial because the adult stem cells can be obtained with the consent of their donor http://www.stemcellresearchfacts.com/definition.html

Video http://www.youtube.com/watch?v=27skh7prkN0&feature=related

Think – Pair - Share Why do we care about stem cells? How are they used in the field of scientific research? As tax payers in NJ, do we allocate our tax money for this research?? (What do you think?)

Quiz is on… Cell Cycle Phases of Mitosis Interphase (G1, S, G2) Mitosis (PMAT) Cytokinesis Phases of Mitosis Cell Regulation (CDK, Checkpoints, and cyclins) Cancer Stem Cells Apoptosis Cell Volume VS. Surface Area Ratio

As a review…. Draw out the stages of mitosis using colored pencils of a cell with 6 chromosomes.