Bellwork: Oct. 3, 2016 look on page 200 of your book 1. What is the smooth ER and what does it do? 2. What is the rough ER and what does it do? http://cellsalive.com/cells/cell_model.htm

Bellwork: please label the parts if you did not! 2

7-3  Cell Boundaries Photo Credit: © Quest/Science Photo Library/Photo Researchers, Inc.

Cell membrane a thin, flexible barrier that surrounds cells. Cell wall: a strong supporting layer around the membrane.

Cell Membrane : regulates what enters & leaves the cell & provides protection and support.

Cell Membrane Outside of cell Carbohydrate chains Proteins The cell membrane regulates what enters and leaves the cell. Inside of cell (cytoplasm) Protein channel Lipid bilayer

What is the main function of the cell wall? support

Cell walls are found in plants, algae, fungi, and many prokaryotes.

Measuring Concentration A solution is a mixture of two or more substances. solutes are the substances dissolved in the solution The concentration of a solution is the mass of solute in a given volume of solution, or mass_ volume.

What happens during diffusion? Substances move from high to low concentration

Diffusion Through Cell Boundaries Diffusion: particles in a solution tend to move from an area where they are more concentrated to an area where they are less concentrated. Equilibrium: When the concentration of the solute is the same throughout a system, http://How Diffusion Works__how_diffusion_works.html

Diffusion Through Cell Boundaries Diffusion is the process by which molecules of a substance move from areas of higher concentration to areas of lower concentration. Diffusion does not require the cell to use energy.

What is osmosis? When H20 diffuses through a cell membrane from H to L [ ]

Osmosis: the diffusion of water through a selectively permeable membrane.

Selectively permeable membrane How Osmosis Works Dilute sugar solution (Water more concentrated) Concentrated sugar solution (Water less concentrated) Sugar molecules Osmosis is the diffusion of water through a selectively permeable membrane. In the first beaker, water is more concentrated on the right side of the membrane. As a result, the water diffuses (as shown in the second beaker) to the area of lower concentration. Movement of water Selectively permeable membrane

How osmosis works: http://highered.mheducation.com/sites/0072495855/student_view0/chapter2/animation__how_osmosis_works.html

Water tends to diffuse from a highly concentrated region to a less concentrated region. If you compare two solutions, three terms can be used to describe the concentrations: hypertonic (“above strength”). hypotonic (“below strength”). isotonic (“same strength”)

Osmotic Pressure  Osmosis exerts a pressure known as osmotic pressure on the hypertonic side of a selectively permeable membrane.

http://www.youtube.com/watch?v=7-QJ-UUX0iY

Facilitated Diffusion Glucose molecules Facilitated Diffusion During facilitated diffusion, molecules, such as glucose, that cannot diffuse across the cell membrane’s lipid bilayer on their own move through protein channels instead. Protein channel

Flip your paper over and write this on the back…………..

Facilitated diffusion: process of diffusion, aided by transport proteins -the spontaneous passage of molecules or ions across a cell membrane form of passive transport = no energy required.

Now….. required

Active Transport: when cells move materials in the opposite direction from which the materials would normally move—that is against a concentration difference. Active transport requires energy.

Molecular Transport In active transport, small molecules and ions are carried across membranes by proteins in the membrane. Energy use in these systems enables cells to concentrate substances in a particular location, even when diffusion might move them in the opposite direction.

Molecular Transport Active Transport Molecule to be carried Active transport of particles against a concentration difference requires transport proteins and energy.

Endocytosis and Exocytosis Active Transport Endocytosis and Exocytosis  Endocytosis is the process of taking material into the cell. Two examples of endocytosis are: phagocytosis pinocytosis

Phagocytosis: A process destroying dead or foreign cells by engulfing or “eating” them. Macrophages are the scavenger cells that are part of this process. phagocytosis in action

Copyright Pearson Prentice Hall

Pinocytosis: when a cell takes in extracellular fluid by a folding of the cell membrane – a droplet becomes bound to the membrane and a pocket forms and pinches off to form a vesicle, which then ruptures, releasing its contents into the cytosol. Pinocytosis – is sometimes called "cell drinking"

During exocytosis, materials are forced out of the cell.

Membrane Transport

Unlike a cell wall, a cell membrane is composed of a lipid bilayer. 7-3 Unlike a cell wall, a cell membrane is composed of a lipid bilayer. provides rigid support for the surrounding cell. allows most small molecules and ions to pass through easily. is found only in plants, fungi, algae, and many prokaryotes.

The concentration of a solution is defined as the 7-3 The concentration of a solution is defined as the volume of solute in a given mass of solution. mass of solute in a given volume of solution. mass of solution in a given volume of solute. volume of solution in a given mass of solute.

move by diffusion from inside the cell to outside. 7-3 If a substance is more highly concentrated outside the cell than inside the cell and the substance can move through the cell membrane, the substance will move by diffusion from inside the cell to outside. remain in high concentration outside the cell. move by diffusion from outside to inside the cell. cause water to enter the cell by osmosis.

facilitated diffusion. active transport. osmosis. diffusion. 7-3 The movement of materials in a cell against a concentration difference is called facilitated diffusion. active transport. osmosis. diffusion.

facilitated diffusion. osmosis. 7-3 The process by which molecules diffuse across a membrane through protein channels is called active transport. endocytosis. facilitated diffusion. osmosis.

Bellwork: Tues. Sept. 23, 2014 Write the organelle: 1. powerhouse = suicide sac = canal system = protein factory = “brain” = packaging center = What 3 things do plant cells have that animal cells lack? 1. 2. 3.

Bellwork: Tues. Sept. 23, 2014 suicide sac = canal system = Write the organelle: 1. powerhouse = suicide sac = canal system = protein factory = “brain” = packaging center = mitochodria lysosome Endoplasmic reticulum ribosome nucleus Golgi body