STARTER: 10/22/2013 answer 3-5 complete sentences. Define the following in your own words using complete sentences. Use the words in parenthesis as part of the sentence. Protein (polymer) Glucose (monomer) Fatty acids (monomer) Nucleic acid (polymer)

Table of Contents Date Lecture/ Activity/ Lab Page Grade 9/9 Practice: Food Webs & Food Chains 9/10 Practice: Ecological Pyramids 9/16 Practice: Carbon Cycle Notes 9/16 Application: Carbon Cycle Activity 9/17 Application: Nitrogen Cycle Activity 9/23 Practice: Biomolecule notes 10/1 Practice: Enzyme Notes 10/8 Practice: Basic Cell Structure: Prokaryote vs. Eukaryote 10/21 Diffusion Intro and Notes

Diffusion & Osmosis

Diffusion The movement of molecules from an area of high concentrated to a area of low concentration No energy required

Osmosis  The diffusion of water across a selectively permeable membrane – no energy required –Movement of water molecules from high concentration to low concentration.

Selectively Permeable Membrane  A membrane that allows only certain materials to cross it  Materials pass through pores in the membrane  Our cell membranes are selectively permeable

Osmosis hill.com/sites/ /student_view0/chapter2/animation__how_osmosi s_works.html

Facilitated Diffusion  Movement of specific molecules across cell membranes through protein channels – no energy required

Why are osmosis & diffusion important?

 All living things have certain requirements they must satisfy in order to remain alive. These include exchanging gases (usually CO 2 and O 2 ), taking in water, minerals, and food, and eliminating wastes. These tasks ultimately occur at the cellular level, and require that molecules move through the membrane that surrounds the cell.

Why are osmosis & diffusion important?  The cell membrane is a complex structure that is responsible for separating the contents of the cell from its surroundings, for controlling the movement of materials into and out of the cell, and for interacting with the environment surrounding the cell.

Endocytosis  Process by which a cell takes material into the cell by “infolding” of the cell membrane  Endo meansIn  Requires energy

Exocytosis  Process by which a cell releases large amounts of material  Exo means exit  Requires energy

Active Transport  Movement of materials across a membrane from low to high concentration using energy  Aka ion-protein Pump  Requires energy

Homeostasis  Maintenance of a relatively stable internal environment –[homeo]=same; [stasis]=stay –The internal environment of a cell is everything on the inside of the plasma membrane

Maintaining Homeostasis  Essential for the survival of each cell  Every cell contributes to the goal of maintaining homeostasis  Every organ system(remember there are 11) contributes to the maintenance of homeostasis in your body

Tonicity

Isotonic  when the concentration of solutes is the same on each side of the cell membrane –homeostasis

Hypertonic  greater concentration of solutes outside of a cell –This causes water to leave the cell (cell shrinks)

Hypotonic  lesser concentration of solutes outside the cell –This causes water to flood the cell (cell swells)

Vocabulary Flash Cards Grading Rubric 20 points: The word (spelled correctly) 50 points: A simplified definition 30 points: A picture associated with the word to help you remember what it means

Cellular Homeostasis Vocabulary  Diffusion  Osmosis  Facilitated diffusion  Active transport  Hypertonic  Hypotonic  Isotonic  Endocytosis  Exocytosis  Semi-permeable membrane

Example  Lipid bilayer  The two layers of phospholipids that make up the cell membrane

Exit: 10/22  Use a Venn Diagram or a T-chart to list the similarities and differences between osmosis and diffusion