CellularTransportandtheCellCycle

** Cellular Transport and the Cell Cycle **

** @https://eapbiofield.wikispaces.com/file/view/cellcycle_eng.jpg ** What you’ll learn:  You will discover how molecules are transported across the plasma membrane.  You will sequence the stages of cell division.  You will identify the relationship between the cell cycle and cancer.

** Section 1-Cellular Transport ** ** Review Vocabulary: ** Plasma membrane-the boundary between the cell and its environment ** New Vocabulary: ** Osmosis  Isotonic solution  Hypotonic solution  Hypertonic solution  Passive transport  Facilitated diffusion <span style="font-family: Arial,Helvetica,sans-serif; font-size: 14pt;"> Active transport <span style="font-family: Arial,Helvetica,sans-serif; font-size: 14pt;"> Endocytosis <span style="font-family: Arial,Helvetica,sans-serif; font-size: 14pt;"> Exocytosis

<span style="font-family: Arial,Helvetica,sans-serif;">__ Osmosis: Diffusion of water- __ Osmosis is the diffusion of water across a selectively permeable membrane. It maintains the homeostasis of the plasma membrane within the cell and regulates the water flow. This means that it makes sure the water does not flow like a waterfall but has more than a stream. <span style="font-family: Arial,Helvetica,sans-serif;">[]

<span style="font-family: Arial,Helvetica,sans-serif;">** What controls osmosis? ** A solvent is something that dissolves into a solution, like dissolving Koolaid into water. If you add too much Koolaid to the water, it will be too sweet. But if you add too much water, then it won’t be sweet enough. This means that the particles diffuse until it is in equal concentration on both sides of the membrane, creating an unequal distribution, Unequal distribution is called a concentration gradient and controls osmosis.

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<span style="font-family: Arial,Helvetica,sans-serif;">** Cells in an isotonic solution- ** In an isotonic solution, the concentration of dissolved substances in the solution is the same as the concentration of dissolved substances inside the cell. Cells in an isotonic solution do experience osmosis, but because water diffuses into and out of the cells at the same speed, the cells retain their normal shape. <span style="font-family: Arial,Helvetica,sans-serif;">Isotonic solution []

<span style="font-family: Arial,Helvetica,sans-serif;">** Cells in a hypotonic solution- ** In a hypotonic solution, the concentration of dissolved substances is lower in the solution outside the cell than the concentration inside the cell. That means there is more water outside the cell than inside the cell. These cells also experience osmosis. Water moves through the plasma membrane into the cell and the cell swells as its pressure inside goes up. <span style="font-family: Arial,Helvetica,sans-serif;">Hypotonic Solution []

<span style="font-family: Arial,Helvetica,sans-serif;">** Cells in a hypertonic solution- ** In a hypertonic solution, the concentration of dissolved substances outside the cell is greater than the concentration inside the cell. These cells experience osmosis that causes water to flow out. <span style="font-family: Arial,Helvetica,sans-serif;">Hypertonic solution []

<span style="font-family: Arial,Helvetica,sans-serif;">__ Passive transport: __ Passive transport is the movement of particles across the membrane, like when iodine and starch molecules come in contact and you get purple starch. <span style="font-family: Arial,Helvetica,sans-serif;">[]

<span style="font-family: Arial,Helvetica,sans-serif;">** Passive transport by proteins- ** Transport proteins help substances move across a plasma membrane through a process called facilitated diffusion. <span style="font-family: Arial,Helvetica,sans-serif;">[]

<span style="font-family: Arial,Helvetica,sans-serif;">__ Active Transport: __ Active transport is the movement of materials through a membrane against a concentration gradient. <span style="font-family: Arial,Helvetica,sans-serif;">** How active transport occurs: ** A carrier protein first binds with particles of the substance to be transported. Chemical energy allows the cell to be moved and release the carrier protein on the other side of the membrane. Active transport also allows particle movement into or out of the cell against a concentration gradient. <span style="font-family: Arial,Helvetica,sans-serif;">[]

<span style="font-family: Arial,Helvetica,sans-serif;">__ Transport of Large Particles __ : This process relies heavily on processes called endo and exocytosis__.__ Endocytosis is when the cell takes material in from its environment, such as a vacuum sucking in dirt. Exocytosis is excluding materials from a cell, such as ridding trash from your home. <span style="font-family: Arial,Helvetica,sans-serif;">[|http://www.emc.maricopa.edu/faculty/farabee/BIOBK/endocytosis.gif\]

<span style="font-family: Arial,Helvetica,sans-serif;">** Endocytosis **

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<span style="font-family: Arial,Helvetica,sans-serif;">** Exocytosis **

<span style="font-family: Arial,Helvetica,sans-serif;">** Section 2-Cell Growth and Reproduction **

<span style="font-family: Arial,Helvetica,sans-serif;">** Review Vocabulary: ** <span style="font-family: Arial,Helvetica,sans-serif; font-size: 14pt;">Organelle-the membrane-bound structure within eukaryotic cells. <span style="font-family: Arial,Helvetica,sans-serif;">** New Vocabulary: ** <span style="font-family: Arial,Helvetica,sans-serif; font-size: 14pt;">Chromosome <span style="font-family: Arial,Helvetica,sans-serif; font-size: 14pt;"> Chromatin <span style="font-family: Arial,Helvetica,sans-serif; font-size: 14pt;"> Cell Cycle <span style="font-family: Arial,Helvetica,sans-serif; font-size: 14pt;"> Interphase <span style="font-family: Arial,Helvetica,sans-serif; font-size: 14pt;"> Mitosis <span style="font-family: Arial,Helvetica,sans-serif; font-size: 14pt;"> Prophase <span style="font-family: Arial,Helvetica,sans-serif; font-size: 14pt;"> Sister Chromatid <span style="font-family: Arial,Helvetica,sans-serif; font-size: 14pt;"> Centromere <span style="font-family: Arial,Helvetica,sans-serif; font-size: 14pt;"> Centreole <span style="font-family: Arial,Helvetica,sans-serif; font-size: 14pt;"> Spindle <span style="font-family: Arial,Helvetica,sans-serif; font-size: 14pt;"> Metaphase <span style="font-family: Arial,Helvetica,sans-serif; font-size: 14pt;"> Anaphase <span style="font-family: Arial,Helvetica,sans-serif; font-size: 14pt;"> Telophase <span style="font-family: Arial,Helvetica,sans-serif; font-size: 14pt;"> Cytokinesis <span style="font-family: Arial,Helvetica,sans-serif; font-size: 14pt;"> Tissue <span style="font-family: Arial,Helvetica,sans-serif; font-size: 14pt;"> Organ <span style="font-family: Arial,Helvetica,sans-serif; font-size: 14pt;"> Organ system <span style="font-family: Arial,Helvetica,sans-serif;">__ Cell Size Limitations __ Cells come in various shapes and sizes. <span style="font-family: Arial,Helvetica,sans-serif;">** Diffusion Limits Cell Size: ** Nutrients and wastes are moved by diffusion in a cell. But because diffusion is a slow process, they have to wait months before receiving molecules. This causes size variation. <span style="font-family: Arial,Helvetica,sans-serif; font-size: 14pt;"> []

<span style="font-family: Arial,Helvetica,sans-serif;">** DNA Limits Cell Size ** : The cell cannot survive unless there is enough DNA to support the protein needs of the cell. Large amounts of DNA ensure that cell activities are carried out quickly and efficiently. <span style="font-family: Arial,Helvetica,sans-serif;">__ http://www.scq.ubc.ca/wp-content/dna.gif __

<span style="font-family: Arial,Helvetica,sans-serif;">** Surface Area to Volume Ratio: ** As the cell size increases, its volume increases faster than its surface area. This is another one of its limiting factors. For example: if a cell doubled in size, its volume would be eight times bigger. This is bad for a cell because it requires more nutrients and it produces more waste.

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<span style="font-family: Arial,Helvetica,sans-serif;">__ Cell Reproduction __ Cell division is when one cell divides into two identical cells. Old cells can be replaced with new cells, such as your liver. Its cells are constantly replacing each other, so eventually you end up with a new liver. This happens frequently. All organisms grow and change so old cells are repaired or replaced by new cells.

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 14pt;">[|http://mail.watertown.k12.ma.us:81/~kboudreau/Study%20Guides/wmssg/Gr7HP/Gr7SCI/SG/Gr7SGrfx/celldivision.jpg]

<span style="font-family: Arial,Helvetica,sans-serif;">** The Discovery of Chromosomes: ** Chromosomes are short stringy structures that contain DNA. Scientists first noticed that they appeared in the nucleus but then vanished after cell division. They then figured out that chromosomes carry the genetic material that is vital to the identity to the cell. <span style="font-family: Arial,Helvetica,sans-serif; font-size: 14pt;"> The Structure of Eukaryotic Chromosomes: Chromatin are long strands of DNA wrapped around specific proteins called histones. Before a cell can divide, the long strands of chromatin must be reorganized. As the nucleus divides, chromosomes take on a different structure where the chromatin becomes tightly packed.

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<span style="font-family: Arial,Helvetica,sans-serif;">__ The Cell Cycle: __ The cell cycle is the sequence of growth and division of the cell. During interphase, a cell grows in size, and carries on metabolism. Chromosomes are duplicated so they can be divided. Interphase is where the cell spends most of its life. After that, the cell undergoes mitosis which is the process by which two daughter cells are formed that have a complete set of chromosomes. After mitosis, the cytoplasm divides, which separates the daughter cells.

<span style="font-family: Arial,Helvetica,sans-serif;">__ https://eapbiofield.wikispaces.com/file/view/cellcycle_eng.jpg __ <span style="font-family: Arial,Helvetica,sans-serif;">__ Interphase: A Busy Time! __ Interphase is divided into three parts. In the first part, the cell grows, and protein production is high. Next, the cell copies its chromosomes and enters a third period of growth. This is where mitochondria and other organelles are manufactured as well as other parts needed for cell division.

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 14pt;">[] <span style="font-family: Arial,Helvetica,sans-serif;">__ The Phases of Mitosis: __ Cells go through mitosis when they are about to reach their maximum size, sort of like going on a diet. Mitosis has four phases, sort of like how a diet plan requires different steps.

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<span style="font-family: Arial,Helvetica,sans-serif;">** Prophase-The first phase of mitosis: ** In the longest phase of mitosis, the long and stringy chromatin coils up into chromosomes, which are made up of two halves. The two halves are called sister chromatids, which are held together by a centromere. Centromeres are important for chromosome movement and also help scientists study and identify chromosomes. In prophase, the nucleus disappears because the nuclear envelope and nucleolus disappear. Centrioles are small, dark, round structures outside the nucleus that move to opposite ends of the cell. While the centrioles move, the spindle forms. A spindle is a cage-like structure that is made of thin fibers and microtubules.

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<span style="font-family: Arial,Helvetica,sans-serif;">** Anaphase-The second stage of mitosis: ** In prophase, the chromosomes doubled. In metaphase, these chromosomes attach to the spindle by their centromeres. The chromosomes then line up at the center of the cell, and each sister chromatid gets its own spindle fiber to attach to. The spindle fibers extend to opposite sides of the center pole, which insures that each new cell has a full set of chromosomes.

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 14pt;">[] <span style="font-family: Arial,Helvetica,sans-serif;">** Metaphase-The third phase of mitosis: ** During metaphase, the sister chromatids then separate by shortening the spindle fibers as the centromeres split apart.

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 14pt;">[] <span style="font-family: Arial,Helvetica,sans-serif;">** Telophase-The fourth stage of mitosis: ** During telophase, the last phase of mitosis, the chromatids reach the opposite poles of the cell. The coiled chromosomes then begin to unwind so they can help out the new cells with activities. As the spindle disappears, the nucleus reappears. Each chromosome gets a new nuclear envelope that is formed around it. A double membrane forms in between these new nuclear envelopes.

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 14pt;">[] <span style="font-family: Arial,Helvetica,sans-serif;">__ Cytokinesis: __ The cell’s cytoplasm then divides in a process called cytokinesis. In animals, the plasma membrane pinches in along the equator and the two new cells are separated. But in plant cells, the plasma membrane does not pinch because there is cell plate, which causes the two new cells to grow on both sides of the cell plate.

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<span style="font-family: Arial,Helvetica,sans-serif;">__ Results of Mitosis: __ When mitosis is complete, unicellular organisms remain as single cells because the organism multiplied. Cell growth results in groups of tissue that organize in various combinations and carry out specific functions. Tissue form organs that perform a complex role for the body, like the heart or lungs. Multiple organs made of multiple tissues make a organ system, like the respiratory system that helps you breathe,

<span style="font-family: Arial,Helvetica,sans-serif;">Section 3-Control of the Cell Cycle <span style="font-family: Arial,Helvetica,sans-serif;">** Review Vocabulary: ** <span style="font-family: Arial,Helvetica,sans-serif; font-size: 14pt;">Protein-a large complex polymer composed of carbon, hydrogen, oxygen, nitrogen, and sometimes sulfur. <span style="font-family: Arial,Helvetica,sans-serif;">** New Vocabulary: ** <span style="font-family: Arial,Helvetica,sans-serif; font-size: 14pt;">Cancer <span style="font-family: Arial,Helvetica,sans-serif; font-size: 14pt;"> Gene <span style="font-family: Arial,Helvetica,sans-serif;">__ Normal Control of the Cell Cycle: __ <span style="font-family: Arial,Helvetica,sans-serif; font-size: 14pt;">In this section, we will explore why cell divide at different speeds and what tells a cell when it is time to begin the next stage of the cell cycle. <span style="font-family: Arial,Helvetica,sans-serif;">** Proteins and enzymes control the cell cycle: ** The cell cycle is controlled by proteins called cyclins and a set of enzymes that attach to the cyclins activate. Cell can lose control of the cell cycle, like an unruly child, and result in cancer. Cancer is malignant growth resulting from uncontrolled cell division. This means that the cell is dividing quickly and uncontrollably due to the changes in enzyme production. This is why cancer is hard to stop and treat (because it spreads quickly). Genes are a segment of DNA that controls the production of a protein, and they direct enzyme production. <span style="font-family: Arial,Helvetica,sans-serif; font-size: 14pt;"> enzymes: http://isbibbio.wikispaces.com/file/view/enzymes.gif

<span style="font-family: Arial,Helvetica,sans-serif;">__ Cancer: Mistake in the Cell Cycle- __ Cancer happens from mistakes or changes in the cell cycle. These changes are expressed as cancer when something prompts the damaged genes into action. Cancer cells that form massive tissue are called tumors, like a brain tumor, and deprive normal cells of nutrients. <span style="font-family: Arial,Helvetica,sans-serif;">** The causes of cancer: ** Cancer can be caused by mainly environmental factors and genetic factors. An environmental factor would be secondhand smoke. A genetic factor would be that maybe your mom or dad had cancer. <span style="font-family: Arial,Helvetica,sans-serif; font-size: 14pt;"> 1 2 <span style="font-family: Arial,Helvetica,sans-serif; font-size: 14pt;"> 1[] <span style="font-family: Arial,Helvetica,sans-serif; font-size: 14pt;"> 2[]

<span style="font-family: Arial,Helvetica,sans-serif;">** Cancer Prevention: ** To help prevent cancer, make healthy choices like avoiding alcohol, smoke, and other toxins as well as excessive exposure to the sun. Make sure to wear sunscreen! Eating healthy and exercising can also help. Vitamins and minerals are keys to preventing cancer.

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<span style="font-family: Arial,Helvetica,sans-serif; font-size: 14pt;">Quiz: <span style="font-family: Arial,Helvetica,sans-serif; font-size: 14pt;"> 1. What is the result of uncontrolled division of cells? <span style="font-family: Arial,Helvetica,sans-serif; font-size: 14pt;"> 2. Small dark structures that are made of microtubules and located outside the nucleus are called ___?__ <span style="font-family: Arial,Helvetica,sans-serif;">__ 3. Diffusion of water across a semi-permeable membrane is called ____?__ <span style="font-family: Arial,Helvetica,sans-serif;"> __ 4. ___ is the period of nuclear division in a cell. <span style="font-family: Arial,Helvetica,sans-serif; font-size: 14pt;">5. What kind of environment is described when the concentration of dissolved substances is greater outside than inside the cell? <span style="font-family: Arial,Helvetica,sans-serif; font-size: 14pt;"> a. Hypotonic <span style="font-family: Arial,Helvetica,sans-serif; font-size: 14pt;"> b. Hypertonic <span style="font-family: Arial,Helvetica,sans-serif; font-size: 14pt;"> c. Isotonic <span style="font-family: Arial,Helvetica,sans-serif; font-size: 14pt;"> d. Saline <span style="font-family: Arial,Helvetica,sans-serif; font-size: 14pt;"> 6. What is osmosis? <span style="font-family: Arial,Helvetica,sans-serif; font-size: 14pt;"> 7. What are chromosomes made of? <span style="font-family: Arial,Helvetica,sans-serif; font-size: 14pt;"> a. Cytoplasm <span style="font-family: Arial,Helvetica,sans-serif; font-size: 14pt;"> b. Diffusion <span style="font-family: Arial,Helvetica,sans-serif; font-size: 14pt;"> c. Endocytosis <span style="font-family: Arial,Helvetica,sans-serif; font-size: 14pt;"> d. Exocytosis

<span style="font-family: Arial,Helvetica,sans-serif;">[|Cellular Transport through Prot]

<span style="font-family: Arial,Helvetica,sans-serif;">[|Passive and Active Transport]

<span style="font-family: Arial,Helvetica,sans-serif;">[|Active Transport]

<span style="font-family: Arial,Helvetica,sans-serif;">[|Passive Transport]

<span style="font-family: Arial,Helvetica,sans-serif;">[|Endocytosis and Exocytosis]

<span style="font-family: Arial,Helvetica,sans-serif;">[|Fluid Mosiac Model]

<span style="font-family: Arial,Helvetica,sans-serif;">[|Cell Cycle]

<span style="font-family: Arial,Helvetica,sans-serif;">[|Mitosis: An Interactive Animation]

<span style="font-family: Arial,Helvetica,sans-serif;">[|Animation: Stages of Meiosis]

<span style="font-family: Arial,Helvetica,sans-serif;">[|Meiosis Animation]