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Lipids Homework Read p. 62-64, “Lipids” Questions to Ponder Why do grocery store owners constantly spray their fruits and vegetables with water? We have “reduced salt areas” on our highways to preserve the plants that grow along the highway. Why would salted roads be bad for them? Why would shipmen and pirates have died if they’d drunk ocean water while sailing at sea? Objectives Understand what a fat is, the different kinds of fats, which ones are less healthy to consume and why? Check out a nutrition panel… – – – – – – Saturated fat? Unsaturated fat? Polyunsaturated fat? Monounsaturated fat? Trans fats? Hydrogenated fat? What do you know about… Why are we told that saturated fats are bad for us and hydrogenated fats are REALLY bad for us, while unsaturated fats aren’t so bad? QuickTime™ and a decompressor are needed to see this picture. QuickTime™ and a decompressor are needed to see this picture. Macromolecules QuickTime™ and a decompressor are needed to see this picture. All matter is made of atoms, so understanding living things = understanding basic chemistry. A molecule is a unit of atoms bonded together. A macromolecule is a very large and complex molecule. Biochemistry! An organic compound = in at least one place, two carbons are bonded to each other. (think organic = organism) – Organic compounds are the chemical basis of living things. Macromolecules Lipids Nucleic acids Amino acids Carbohydrates We’ll learn about them one by one over the semester. Lipids QuickTime™ and a decompressor are needed to see this picture. There are many types of lipids, including steroids, cholesterols, sphingolipids, prenol lipids, and saccharolipids. We’re going to focus on just two types: – Fatty acids and triglycerides – Phospholipids Lipids Easy to recognize! They’re made of long chains of carbon atoms (C) with hydrogen atoms (H) attached. Here’s one example (three different ways of representing the same chemical): Palmitic acid Lipids Scientists often abbreviate that chemical diagram to something like this: Saturated vs Unsaturated Saturated means “full of something.” Saturated fats are completely full of hydrogens. Saturated vs Unsaturated Unsaturated means “not full.” Unsaturated Fats = carbons aren’t totally surrounded by hydrogens. Saturated vs Unsaturated The difference between saturated and unsaturated is being full of hydrogens. Saturated= a straight line. Unsaturated = has a kink. “Good” vs “Bad” fats Saturated = straight chains pack together to make it solid. QuickTime™ and a decompressor are needed to see this picture. Unsaturated = crooked chains can’t pack together, it stays a liquid. QuickTime™ and a decompressor are needed to see this picture. “Good” vs “Bad” Fats (By the way, a “hydrogenated fat” is a man-made saturated fat, and a “trans fat” is an especially harmful kind of hydrogenated fat.) QuickTime™ and a decompressor are needed to see this picture. Good vs. Bad fats – Saturated fats, because they’re solid, can clog up an artery like a traffic jam, preventing blood from flowing through. – Saturated fats in their rigid regular structures are also harder to break down for energy and easier to store. Phospholipids Phospholipids – Make up cell membranes. Polarity Water is polar, like a magnet. When it meets other compounds that are also polar, just like magnets, they tend to attract each other and stick together. We call compounds like that hydrophilic. Latin/Greek: Phil = Love <3 Polarity If a molecule isn’t polar, it tends to be hydrophobic. Water and a hydrophobic compound move away from each other. Latin/Greek: Phobia = Fear Polarity The phosphorus end is polar, so it’s hydrophilic. The two lipid chains are hydrophobic, they separate from water just like oil. Phosphorus head = hydrophilic Fatty acid tails = hydrophobic QuickTime™ and a decompressor are needed to see this picture. Polarity If you get more than one phospholipid in the same place, they act in a predictable way because of the attraction and repulsion from the water they’re in. Simulation http://telstar.ote.cmu.edu/biology/Membra nePage/index2.html Et voila… The inevitable chemical result is a membrane! QuickTime™ and a decompressor are needed to see this picture. We call these layers of two lipids a phospholipid bilayer. (Latin/Greek table: Bi = two.) The cell membrane of every living thing is a phospholipid bilayer. Et voila… QuickTime™ and a decompressor are needed to see this picture. Fluid Mosaic Model Proteins are embedded in a cell membrane. QuickTime™ and a decompressor are needed to see this picture. QuickTime™ and a decompressor are needed to see this picture. Fluid Mosaic Model QuickTime™ and a decompressor are needed to see this picture. The membrane = a fluid mosaic model, because the mixed parts can flow around each other. Macromolecule Table S hape Carbohydrate Amino acid Nucleic acid Lipid Name Biochemistry Types Key Locations Functions/Uses Other Check for Understanding Time to bestow some stickers! – Put your notes away and keep just a blank piece of paper. I will ask 9 questions about lipids. Confer with your tablemate and decide on the correct answer. – The table or tables that get the most questions correct, get one sticker per person. Check for Understanding 1. Which of these is not a lipid? – A. Triglyceride – B. Carbohydrate – C. Phospholipid 2. Which kind has a kink in it, saturated or unsaturated fats? 3. What are saturated fats saturated with? Check for Understanding 4. Having a kink in it makes a fat a… – A. Solid. – B. Liquid. – C. Gas 5. Which part of a phospholipid is hydrophilic? – A. The phosphorus head – B. The pholi body – C. The lipid tails 6. What is the shape or identifying feature of a lipid? Check for Understanding 7. What kind of lipid makes up a cell membrane? 8. In a phospholipid bilayer, why are the tails on the inside and the heads on the outside? 9. Which cell organelle is a described by the fluid mosaic model? Plasma Membrane Selectively permeable membrane = a membrane that some things can cross and others can’t. – The cell membrane is selectively permeable, because of its phospholipid fluid mosaic structure. Cell Membrane There are four ways that things can move in or out of a cell: Simple Diffusion, Facilitated Diffusion, Osmosis, and Active Transport. We begin with Passive Diffusion. Observe! Diffusion Dye in water Move out, troops. In a quiet and orderly fashion listening to all directions. Diffusion Diffusion = The movement of particles from a place where they are highly concentrated to a place where they are not highly concentrated. – It happens because molecules are in constant motion. Diffusion http://highered.mcgrawhill.com/sites/0072495855/student_view 0/chapter2/animation__how_diffusion_w orks.html Simple Diffusion One way for things to get in and out of a cell… Simple Diffusion = The diffusion of small molecules across the cell membrane. – Simple diffusion diffusion happens to it automatically. Simple Diffusion QuickTime™ and a decompressor are needed to see this picture. Facilitated Diffusion If a molecule is too big for simple diffusion, the cell membrane has some protein channels (like windows). QuickTime™ and a decompressor are needed to see this picture. Facilitated Diffusion Facilitated Diffusion = Diffusion helped by proteins in the cell membrane. – Just like Simple Diffusion, Facilitated Diffusion doesn’t cost the cell any energy. QuickTime™ and a decompressor are needed to see this picture. Facilitated Diffusion http://highered.mcgrawhill.com/sites/0072495855/student_view 0/chapter2/animation__how_facilitated_ diffusion_works.html Vocab Review Macromolecule Lipid Phospholipid Phospholipid Bilayer Fluid Mosaic Model Hydrophilic Hydrophobic Diffusion Simple Diffusion Facilitated Diffusion Selectively Permeable Membrane