Lipids Lipids like carbohydrates contain only carbon, hydrogen and oxygen.

Lipids again… We called carbohydrates sugars…what is a more common name for lipids? Fat!!! Oil!!! Wax!!!

The Power of Lard… Fats and oils are chemically similar (we’ll see how soon). How do they differ? At room temp: Fats =Solid Oils =Liquid

Important component of our diet. 1 gram of fat = 2x as much energy as 1 gram of carbohydrate.

McDonalds, here I come…nope! If fats give more energy, why not use them as our main source? There are some health implications (which we’ll get to…), though some people would argue it’s not a bad thing.

I’m getting hungry… Extra calories are stored as fat. All organisms use fats as a means to store energy. Plants store oils in seeds. Humans store fat under their skin (deposition varies).

Forming Lipids Most lipids are composed of 2 different molecules: 1) A glycerol molecule 2) 3 fatty acid molecules

Glycerol? Ok, so what’s glycerol? C C C H H H H H OH

Are you calling me fatty? Let’s look at the fatty acid now: CCC H H H H H HO O Hydro- carbon

Are you calling me fatty? Let’s look at the fatty acid now: CCC H H H H H HO O Carboxyl Group

Fats, not phat… How do we get them to combine? Our old friend dehydration synthesis!!!

Dehyrdation Synthesis of Lipids C C C H H H H H OH Glycerol HO—C—C 10 H 18 O O O + 3 Fatty Acids

Dehyrdation Synthesis of Lipids C C C H H H H H O O O —C—C 10 H 18 O O O + H2OH2OH2OH2OH2OH2O 1 Fat Molecule+ 3 Water Molecules

Good fat or a bad fat? There are two main types of fats. Both appear in the foods we eat. One is said to be good, one bad… Saturated Fat Unsaturated Fat = bad = good

Saturated Vs. Unsaturated What does saturated mean? Saturated = unable to hold more; full What are fats “saturated” with? Hydrogens!!!

More sat. vs. unsat. How can you tell sat fats from unsaturated fats? At room temperature: Saturated fats are solid. Unsaturated fats are liquid.

Animals vs. Plants… Plants tend to store their lipids as oils… Saturated or Unsaturated? Unsaturated!!! Animals store their lipids as fat… Saturated!!!

Butter vs. Margarine Where does butter come from? Milk (animal) fat. How about margarine? Vegetable oil.

Butter vs. Margarine If margarine comes from vegetable oil, why is it a solid at room temp? Hydrogenation!!! What’s that you say? Hydrogenation is the process of adding hydrogen to an unsaturated lipid.

Why hydrogenate? Well, unsaturated fats are better for you… …but if we hydrogenate them, they’re now saturated fats… So what’s wrong with saturated fats?

Popeye was right to love Olive Oil… Saturated fats like meats and butter tend to increase your level of cholesterol… Cholesterol is a steroid that is essential in our bodies. However, too much cholesterol can clog your arteries…

Triple bypass please…

Should I hydrogenate then? In a word, no. Hydrogenating oils not only produces a saturated fat, which we’ve already said is bad, but it also slightly alters the bonds in our lipid… These altered bonds can cause colon-rectal cancer in people predisposed to cancer.

What can I eat then? Try to stick to the unsaturated lipids, the oils…they’re relatively good for you. Otherwise, everything in moderation

Fats: the 2 minute drill What are the two components of a lipid? Glycerol and 3 fatty acids. What are the two main categories of lipids? Saturated and Unsaturated

Fats in focus Saturated fats at room temperature are… solids. Unsaturated fats are…liquids. Glycerol combines with 3 fatty acids through the process of… dehydration synthesis.