Cellular Transport and the Cell Cycle Chapter 8 Cellular Transport and the Cell Cycle Section 8.1 Section 8.2 Section 8.3

Cellular Transport Section 8.1

Movements across the plasma membrane can be divided into two groups! Passive Transport Active Transport

Passive - always high to low conc. - does not require energy 1 Passive - always high to low conc. - does not require energy 1. Diffusion (simple) 2. Osmosis 3. Facilitated diffusion Active - always low to high conc. - NEEDS energy 1. Endocytosis 2. Exocytosis

Diffusion- movement of particles from an area of higher concentration (more particles) to an area of lower concentration (less particles) until an equal concentration is met

1. Simple Diffusion Diffusion of particles by using channel proteins Does not require energy Movement of small molecules like CO2 and O2 Visit www.unitedstreaming.com and search for the video titled Cells the Building Blocks of Life and view the segment called Cell Membrane: Diffusion

2. Facilitated diffusion – passive transport of material across the plasma membrane with the aid of transport proteins Diffusion with the help of carrier proteins Movement of large molecules like glucose

3. Osmosis – diffusion of water across a selective permeable membrane What’s going to happen in this picture? (Blue in water and Green in salt) http://www.biologycorner.com/resources/osmosis.jpg

Water is always trying to reach an equal concentration between a cell and its environment http://www.biologycorner.com/resources/osmosis.jpg

Osmosis – diffusion of water across a selective permeable membrane http://www.biologycorner.com/resources/osmosis.jpg

One factor that controls osmosis is a concentration gradient. Concentration Gradient – an unequal distribution of particles The greater the concentration gradient, the more likely osmosis will occur

Three types of solutions: Isotonic solution – the concentration of dissolved particles in the solution is the same as the number of dissolved particles in the cell -“ Iso” – means same, like an isosceles triangle (two sides are the same length)

2. Hypotonic solution – the concentration of dissolved particles in the solution is less than the number of dissolved particles in the cell - “hypo” means low, as in hypoglycemia (low blood sugar)

- “hyper” means high, as in hyperactive (over excited) 3. Hypertonic solution – the concentration of dissolved particles in the solution is more than the number of dissolved particles in the cell - “hyper” means high, as in hyperactive (over excited)

What’s important about osmosis? How does it affect our cells? Our cells holds 0.9% salt, NO MORE NO LESS Any solution that is = 0.9% is an isotonic solution to our cells Any solution that is > 0.9% is a hypertonic solution to our cells Any solution that is < 0.9% is a hypotonic solution to our cells

A simple rule to remember is: SALT SUCKS Salt is a solute, when it is concentrated inside or outside the cell, it will draw the water in its direction. This is also why you get thirsty after eating something salty.

www.esu7.org/~lweb/Lakeview/science/sea.htm

Active - always low to high conc. - NEEDS energy - NOT diffusion 1 Active - always low to high conc. - NEEDS energy - NOT diffusion 1. Endocytosis 2. Exocytosis Passive - always high to low conc. - does not require energy 1. Diffusion (simple) 2. Osmosis 3. Facilitated diffusion Visit www.unitedstreaming.com and search for the video titled Cells the Building Blocks of Life and view the segment called Cell Membrane: Active Transport

1. Endocytosis – process by which a cell surrounds (with vacuole) and takes in large molecules or groups of molecules ENDO – means “in” to the cell

2. Exocytosis – process in which a cell expulses or secretes materials from cell Exo – means “exit” or excrete Used when cells need to expel wastes Used when cell need to secrete hormones

http://www. biologie. uni-hamburg http://www.biologie.uni-hamburg.de/b-online/library/biology107/bi107vc/fa99/terry/images/ExocyAnA.gif

Cell Growth and Reproduction Section 8.2

The Cell Cycle - sequence of growth (interphase) and division (mitosis) of one cell START HERE http://www.emc.maricopa.edu/faculty/farabee/BIOBK/cellcycle.gif

MITOSIS The process in which cells divide and create two daughter cells with the same genetic material as the parent cell

Phases of Mitosis: Prophase Metaphase Anaphase Telophase

1. PROPHASE Longest phase Sister chromatids appear and are held together by a centromere http://www.fatherryan.org/academic/schmidtl/BioIchapt%208%20notes_files/image004.jpg

Centrioles –located outside the nucleus www.google.com/images

Nucleus starts to disappear Spindle fibers form Nucleus starts to disappear www.google.com/images

www.google.com/images

Shortest phase Chromosomes attach to spindle fibers by their centromere and line up in the middle www.google.com/images

Sister chromatids are pulled apart www.google.com/images

www.google.com/images

Spindle begins to break down New nuclei begin to form www.google.com/images

CYTOKINESIS End of telophase The division of cytoplasm to form two new cells www.google.com/images Or

Tissues Group of cells that begin to work together http://washington.uwc.edu/about/faculty/schaefer_w/TISSUES/fibrous_connective_tissue_tendon.jpg

ORGAN Group of tissues designed to perform a specific function http://www.yankeetown.org/plangley/7.html

ORGAN SYSTEMS Group of organs that work together http://www.tqnyc.org/NYC063547/urinarysystem.html

Control of the Cell Cycle Section 8.3

I. Normal Control of the Cell Cycle A. Enzymes Control the Cell Cycle Necessary to begin and drive the cell cycle, and control the cycle through it’s phases Uncontrolled dividing comes from failure in the production enzymes Cancer – one result of uncontrolled cell division

Enzymes are directed by genes located on the chromosomes Gene – segment of DNA that controls the production of a protein Several enzymes trigger DNA replication

II. Cancer: A Mistake in the Cell Cycle Damaged genes are prompt into action Tumors – mass of cancer cells Metastasis – cancer cells can be seen in the circulatory system (spreads the cancer)

Tumors can benign or malignant. Metastasis = Malignant http://blog.wired.com/photos/uncategorized/2007/05/22/metastasis.jpg

Cancer 2nd Leading cause of death in U.S.A. Most prevalent – lung, colon, breast and prostate http://mbbnet.umn.edu/icons/cancercell.jpeg

A. Causes of Cancer Genetic Environmental – cigarette smoke, air and water pollution, UV radiation Viral infections that damage genes

B. Cancer Prevention Healthy Lifestyle Low fat diets High fiber diets (fruits, vegetables, and grain products) Vitamins and Minerals (carontenoids, Vit A, C and E) Daily exercise Not using Tobacco Products