1.3 Lipids Completed PDF

1.3 – Macromolecules: Lipids 2. LIPIDS Properties: mainly _____________ hydrocarbons, and they group together because they non polar are largely _________________. hydrophobic Examples: includes fats (i), phospholipid...

1.3 – Macromolecules: Lipids 2. LIPIDS Properties: mainly _____________ hydrocarbons, and they group together because they non polar are largely _________________. hydrophobic Examples: includes fats (i), phospholipids (ii), steroids (iii), and wax (iv) i. Fats Called _______________________ triglyceride Structure: Made of _____ 3 fatty acid chains (usually 16-18 carbons long) bonded to ___ 1 glycerol molecule via 3 ______________________ formed by 3 condensation reactions. ester bonds Function: Efficient energy storage! They are very light and compact, one gram of fat stores more than twice as much energy as one gram of carbohydrates, this is why our body turns excess carbs into fat for long-term storage. Also, because their energy is less accessible our bodies will only process fats after it has depleted the carbohydrate stores. Glycerol fatty acids g eyterbond dehydration H2O H2o 12 Question: why are some fats healthier (fish oil) and others less healthy (french fries)? Types of fats: syntheticallyproduced Unsaturated Saturated Monounsaturated Polyunsaturated Trans-fats Structure all one double more than one one or more single bond in cis doublebond doublebonds bonds formation in cis in transformation saturated t formation ay c c with H creates kink in the chain A straightchains straightchain f Properties packtogether bends in fatty acid chain fffada fffgenating tightly prevent tightpacking them andheating at roomtemp solid room liquid changecisbonds to transbond temperature source plant fats moresolid room source animal temp fat risk ofheart disease Sources e Fat on meat ive oil FIstfood butter avocado oil shortening lard canola oil friedfoods 13  ii. Phospholipids amphipathic Structure: Similar to a triglyceride but one of the fatty acid chains is replaced by a _________________ functional group. This give the lipids a ______________________ 0 p o phosphate head and a ___________________ non polar hydrophobic tail. polarhydrophilic 0 Function: The main component of cell membranes, knowns as the phospholipidbilayer hydrophilic hydrophobic Phosggolipid tail iii. Steroids Structure: Basically a 4 ringed carbon skeleton with various attached functional groups Examples: Cholesterol, a component of cell membranes, and sex hormones like estrogen and progesterone. 14 iv. Wax Structure: Long hydrocarbon chains that are solid at room temperature, non-polar and hydrophobic. Examples and Functions: In plants, wax coats the leaves and some fruits to prevent water getting in and for protection against insects (ex. skins of apples). In animals, waxes coat my animals’ fur, feathers and skin for protection from water (“water off a duck’s back”), other examples include earwax, beeswax, and spermaceti wax (think of the story of Moby-Dick). LIPID PRACTICE QUESTIONS 1. Why are some fats healthy and other unhealthy? Give an example of each. Healthyfats naturallyoccurringenergysource Transfats unhealthyhigherrisk of heartdisease 2. Explain why fat is more efficient energy storage than carbohydrates. Onegram of fat stores 2x theenergyof carbohydrates while remainingverylight 15 3. The enzyme lipase, produced by the pancreas, digests triglycerides, draw a diagram to predict how it might break down a triglyceride molecule through hydrolysis. of 420 H2o H2o Textbook Questions: pg.25 #13, 16, 18 16