Vocab Word list 11. Passive Transport 12. Active Transport Know all of these words for the test Diffusion Osmosis Selectively permeable Equilibrium Solution Facilitated Diffusion Hypertonic Hypotonic Isotonic Contractile Vacuole 11. Passive Transport 12. Active Transport 13. Endocytosis 14. Phagocytosis 15. Pinocytosis 16. Exocytosis 17. Protein Pump

Transport Across the Cell Membrane Fluid Mosaic Model Video clip https://www.youtube.com/watch?v=Qqsf_UJcfBc http://www.youtube.com/watch?v=moPJkCbKjBs&feature=relmfu Silent video- cell membrane and how it works https://www.youtube.com/watch?v=QQgXfuFyKM4

Cell Membrane Structure Bi-layer of phospholipids with proteins imbedded Philic heads = water loving Phobic tails= water fearing This helps the cell interact in its aqueous environment. 3

FUNCTIONS 1. Gatekeeper 2. Protects and controls the substances going in and out of the cell 3. Selectively permeable - Only certain substances can pass through the membrane.

Think …..How does this picture show selective permeability?

Think…..How does the gate act like a cell membrane?

Things they want to let in: Things they want to let out: Things they DO NOT want to let in: The cell tries to let in good things and keep out bad things. Often based on size…small things are allowed in and larger things are kept out or have to be pumped in. sugar, oxygen, water carbon dioxide, waste viruses, bacteria

Question 1. Which statement regarding the functioning of the cell membrane of all organisms is not correct? The cell membrane forms a boundary that separates the cellular contents from the outside environment. The cell membrane forms a barrier that keeps all substances that might harm the cell from entering the cell. The cell membrane controls the movement of molecules into and out of the cell. The cell membrane is capable of receiving and recognizing chemical signals.

Question 2. In the given diagram of a single-celled organism, that arrows indicate various activities taking place. Which systems perform these same activities in humans? Respiratory, nervous and endocrine Excretory, respiratory, and reproductive Digestive, circulatory, and immune Respiratory, excretory, and digestive

4. Recognize and respond to signals by using cell receptors (receptor molecules) Allows cell to communicate and maintain homeostasis Are protein molecules on the surface of the membrane with a specific shape. Advanced video Click on image

Protein (cell) Receptor Cell receptors receive information from chemical messengers (i.e. hormone) by matching up with its shape signaling the target cell to respond and produce a desired product Insulin Protein (cell) Receptor Cell Membrane

Question 3. Cellular communication is illustrated in the diagram below Information can be sent from Cell A to Cell B because cell B is able to recognize signal 1 Cell B to Cell A because cell B is able to recognize signal 2 Cell B to Cell A because cell A is able to recognize signal 1 Cell A to Cell B because cell A is able to recognize signal 2

Question 4. Which substance are found on cell surfaces and respond to nerve and hormone signals? Vitamins and minerals Subunits of DNA Receptor molecules Starches and simple sugars

Question 5. Hormones and secretions of the nervous system are chemical messengers that Store genetic information Extract energy from nutrients Coordinate system interactions Carry out the circulation of materials

Question 6. In multicelluar organisms, cells must be able to communicate with each other. Structures that enable most cells to communicate with each other are known as Chloroplasts Pathogenic agents Receptor molecules Antibiotics

TYPES OF TRANSPORT http://www.youtube.com/watch?v=kfy92hdaAH0 No energy required Energy required

1. Passive Transport Requires NO energy http://www.brainpop.com/science/cellularlifeandgenetics/passivetransport/zoom.weml Requires NO energy Diffusion & Osmosis and Facilitated Diffusion – carrier proteins “help” molecules across the membrane

Diffusion molecules move from an area of high concentration to an area of low concentration Molecules tend to “spread out” Requires NO energy Substances that may diffuse: Oxygen, carbon dioxide, glucose, amino acids, water Click on image

Equilibrium When molecules are evenly spread throughout a space

Osmosis Diffusion of water molecules.

Cells in different osmotic solutions Cells behave differently when placed in different solutions! This is due to OSMOSIS! Most cells are ~ 98% water! Three types of osmotic pressure: Isotonic Hypotonic Hypertonic Watch How osmosis works: https://www.youtube.com/watch?v=w3_8FSrqc-I http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter2/animation__how_osmosis_works.html

Basic Rule for Determining types of Osmostic conditions….. Salt “SUCKS" If the area outside the cell has more salt – then water will be “pulled” out of the cell Watch the animation

U - Tubes

Isotonic - "ISO" means the same

Let’s see….Isotonic Condition Cell is placed in 98% water Solution outside of cell has SAME water, same amount of other materials (i.e., salt) Therefore, solution is equal strength (iso) Water moves equally; Equilibrium exists 98% CELL STAYS THE SAME! 98%

Hypotonic (Hypo = less) Water moves in the cell Cell may burst, or organelles called “contractile vacuoles” remove excess water

Let’s see…Hypotonic Condition Cell is placed in 100% water Solution outside of cell has MORE water, less of other materials (i.e., salt) Therefore, solution is below strength (hypo) 100% Water ENTERS cell 98% CELL SWELLS!

HYPERTONIC – “Hyper = above” Water moves out of cell Cell will shrink (Plasmolysis) or die, plants wilt Why is it dangerous to drink sea water? Why does pouring salt on a slug kill it?

Let’s see… Hypertonic Condition Cell is placed in 95% water Solution outside of cell has LESS water, more of other materials (i.e., salt) Therefore, solution is above strength (hyper) Water LEAVES cell 95% 98% CELL SHRINKS!

Gummy Bear Osmosis Lab

Water relations and Cell shape in cells Animal cell: RBC Plant Cell HYPERTONIC HYPERTONIC HYPOTONIC HYPOTONIC

Egg Osmosis http://www.youtube.com/watch?v=SSS3EtKAzYc

Facilitated Diffusion Facilitate- to guide or help. Protein channels help guide some molecules through the cell membrane. Watch animation Let’s see!

2. Active Transport Watch video: https://www.youtube.com/watch?v=2-icEADP0J4 Movement of molecules from areas of low concentration to areas of high concentration. Requires ATP (energy). Against the concentration gradient http://www.brainpop.com/science/cellularlifeandgenetics/activetransport/

Active Transport Figure7-20 Active Transport Molecule to be carried Low Concentration Cell Membrane High Concentration Molecule being carried Low Concentration Cell Membrane High Concentration Energy Energy Go to Section:

Examples of Active Transport : 1. Endocytosis- bring into the cell. 2. Exocytosis- move out of the cell. endo=within exo=outside cyt=cell osis = process of

Endocytosis and Exocytosis

Phagocytosis Cytoplasm extends out and engulfs material to be brought into the cell. White blood cells and amoeba. Watch animation: http://www2.sluh.org/bioweb/bi100/tutorials/thecell/phago_4.html

Watch Summary video Active & passive transport -http://www.youtube.com/watch?v=kfy92hdaAH0