Announcement! 10/29/13

Happy (early) Halloween Bookworms! 

I have a rather exciting announcement to make... ooh the suspense... I have created a NEW blog to post my academic-related stuff! Woot woot! So that means the Black Rose Bookcase will be used for my book reviews ONLY. Double woot woot! So if you're in need of some school-related help, check out http://www.AcademicMagick.blogspot.com. The name is great, I know.

In other news, tomorrow I am going to go listen to some really cool people speak at my library! Guess who it is? PARANORMAL INVESTIGATORS. And guess what else?! THEY WROTE A BOOK. I will definitely be posting a special Halloween post all about that experience, and also an update on what I did for Halloween. 

May the odds be ever in your favor! (I don't know, the old saying got old)

~Your One and Only Black Rose Librarian 
Sam ^_^

AP Biology: Tour of the Cell & Cell Membrane

·       

  All membranes are composed of lipids, proteins, and a little bit of carbohydrates.

·         Daveson-Danielle (1941) model proposed a lipid sandwich with a coat of proteins on either side.

·         The current Singer-Nicholson ‘fluid mosaic’ model envisions membranes as a double-lipid layer “sea” in which protein molecules float like icebergs.

·         The hydrophobic fatty acid tail ends of proteins stick into the lipid layer because they are water-hating.

·         The hydrophilic phosphate head ends stick outside the layer because they are water-loving.

·         Active transport= requires energy or ATP; helped with the use of a pump.

·         Passive transport= does not require energy to occur; random. I.e. diffusion and osmosis.

·         Diffusion=movement of substances other than water from areas of higher concentration to lower concentration.

·         Osmosis=diffusion of water.

·          Dialysis=separating larger molecules and smaller molecules from each other by means of the  membrane.

·         Integral Proteins= go through the phospholipid bilayer.

·         Peripheral Proteins=stationed on the outside of the phospholipid bilayer or on the surface.

·         Embedded in the bilayer are cholesterol and a variety of protein molecules.

o   Channel proteins-passing of certain water-soluble substances across the membrane.

o   Electron transfer proteins- transfer electrons from molecule to molecule.

o   Receptor Protein-binds to molecule it is looking for which triggers receptor to signal endocytosis.

o   Recognition Proteins-recognize and help in some cells sticking to other cells.

o   Transport Proteins-use ATP to transport materials across membrane in process called active transport (requires energy to occur).

·         Selectively Permeable Membrane-only certain substances can pass through.

·         Hypertonic-more outside of the cell.

·         Plasmolysis-water moves outside out of the cell causing it to shrivel up. Occurs in hypertonic.

·         Isotonic-equal amount inside and outside of the cell. Substances leaving and entering the cell at an equal rate.

·         Hypotonic-more inside the cell.

·         Lysis-occurs in in hypotonic cell in which the cell bursts because there is too much water inside of it.

·         Turgid-swollen cell. Occurs in hypertonic. Vacuoles are up to their maximum capacity of holding water.

·         Exocytosis-expulsion of materials from cell.

·         Endocytosis-materials entering the cell.

o   Phagocytosis-cellular eating. The cell engulfs undissolved substances that are too large to pass through the membrane.

o   Pinocytosis-cellular drinking. The cell engulfs dissolved substances that are too large to pass through the membrane.

·         Diffusion and osmosis are similar in that they involve movement across a membrane and both relate to concentration gradient. However, they differ in that osmosis deals with water only and diffusion deals with everything else.

·         The larger the molecules, the tougher a time it will be to pass through the membrane.

·         In the dialysis tubing experiment, iodine diffused into the bag because its molecules were small enough to do pass through the membrane. The starch remained inside of the bag because the molecules were too large. The solution remained an amber-yellow color and the bag turned dark blue due to the concentration of iodine that seeped into the bag.

·         Cell membrane= gives cell shape and holds the cytoplasm.

·         Chloroplast=makes food in a plant cell through process of photosynthesis.

·         Cell wall=thick outer covering that protects and supports plant cells.

·         Vacuoles=store substances.

·         Nucleus=contains genetic material/hereditary information.

·         Centrioles=help with cell division. Only found in animal cells.

·         Nuclear Envelope= allows material to move inside and outside of the nucleus. Nuclear envelope is to nucleus as cell membrane is to cell.

·         Golgi apparatus=packages and stores chemicals made by the cell.

·         Most chemical reactions in a cell take place in the cytoplasm.