Class Notes (836,153)
Canada (509,662)
Nutrition (899)
NUTR 1010 (443)
Lecture 5

Week 5.docx

5 Pages
110 Views
Unlock Document

Department
Nutrition
Course
NUTR 1010
Professor
Jess Haines
Semester
Fall

Description
Week Four – October 1 , 2012 LIPIDS Lipids are a large group of molecules that are not soluble in water and all are non- polar molecules. LIPIDS WE EAT Triglycerides - 95% of our dietary lipid; usually what it means when we say “fat” - We eat triglycerides and store our body fat as triglycerides - Made of 1 glycerol molecule Fatty Acids - Different fatty acids give triglycerides different properties Lengths Length affects how it is digested and processed in the body; its function in the body, and its properties before/when you eat it; ex. Lauric acid – fat in chocolate that makes it feel nice in your mouth, medium length. Short chain: fewer than 6 carbon atoms Medium chain: 6-12 carbon Long chain: 14 or more carbons Saturation Saturated fats (SFA) have no double bonds, while unsaturated fats have 1 or more double bonds (which removes one of the hydrogen molecules). Monounsaturated (mufa) = 1 double bond Polyunsaturated (pufa) = 2 or more double bonds - Affects whether food is a solid or liquid at room temperature (butter is very saturated); how they are processed in the body (poly, do not stack because of the bonds, so molecules can shift around; liquid at room temp); health. Foods with Saturated Fats: all animal foods, ice cream, butter, tropical oils (coconut oil). Monounsaturated: olive oil, canola oil. Polyunsaturated: any vegetable oil, canola, safflower, corn oil, fish, and nuts; omega 3. Where is the double bond? - The bond closest to the end of the fatty acid o Omega end o This bond affects how your body uses the fat. - Omega 3 fatty acids = double bond at the third carbon from the end. th - Omega 6 fatty acids = double at the 6 carbon Shape Cis: hydrogren molecules on the same side as the double bond, creating a kink; most fats in our diet are in the Cis shape Trans: hydrogen molecules on opposite sides; even though it has double bond, acts as though it doesn’t; trans fats can pack tightly like saturated fats and are hard at room temp; is written on food labels while cis is not (assumed to be in everthing); found in milk, cheese, and beef; hydrogenated fats: Crisco, chips, margarine, fries, peanut butter. Name your fatty acid* they are given common names and numerical notations. Ex. 18:2 -3 Phospholipids Consists of a glycerol backbone with two fatty acids and a compound that contains phosphate. Sterols A large group of hydrophobic compounds; found in plant and animals; most common one in animals: cholesterol. Plant sterols are good for heart health; body absorbs sterols instead of cholesterol; functional food – helps fight disease. FAT DIGESTION Mouth: chewing and lingual lipase Stomach: churning into small droplets, gastric lipase Small intestine: bile emulsifies fats into small droplets (micelles); pancreatic lipases break fatty acids off of glycerol; free fatty acids and Mono glycerides FAT ABSORPTION Lipids are not soluble in water, so digesting them requires the help of digestive enzymes from pancreas and bile from gall bladder; cells of intestinal wall secrete hormone (CCK) which causes the gallbladder to contract and release bile into the duodenum (small intestine); it slows down the movement while enzymes break the lipids down; micelles transport the products to the enterocytes of the small intestine. broken down products, along with free chloestoral are trapped in the micelle, then they are transp
More Less

Related notes for NUTR 1010

Log In


OR

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


OR

By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.


Submit