Lipids

A fatty acid is a chain of carbon atoms flanked by hydrogen atoms.

A fatty acid is a ____ of carbon atoms flanked by _____ atoms.

hydrogenation

Chemically changing unsaturated fatty acids into saturated fatty acids by adding hydrogen to double bonds. It changes a liquid oil into a more solid fat. Sometimes forms trans fatty acids

LDL

Cholesterol. Carries cholesterol made by the liver and from other sources to cells

Sterols

Component of cell membranes Component of nervous tissue Synthesis of hormones (e.g., testosterone) Precursor to bile acids (participate in fat digestion)

Many flavors dissolve in fat Smooth, creamy texture

Describe the roles of fat in foods.

Each carbon atom can form a maximum of four chemical bonds. In fatty acids, the carbon atoms are bonded to other carbon atoms, hydrogen atoms, or oxygen atoms.

Each carbon atom can form a maximum of _____ chemical bonds. In fatty acids, the carbon atoms are bonded to other ______ atoms, ______ atoms, or ______ atoms.

omega-3 fatty acids

Examples EPA and DHA

Omega-6 fatty acids

Examples: linoleic acid (essential), arachidonic acid

Reducing fat content may alter the flavor and texture of foods, so food manufacturers may add sugar and salt to compensate.

Explain why "fat-free" is not necessarily the same as "healthy."

Rancidity

Exposure to light, heat, and oxygen causes fatty acids to decompose, resulting in unpleasant tastes and odors. It limits the shelf-life of foods that contain unsaturated fats.

Fat-free: <0.5 g of fat per serving Low-fat: ≤3 g of fat per serving Reduced-fat: at least 25% less fat than reference food

Fat-free: _____ of fat per serving Low-fat: _____ of fat per serving Reduced-fat: at least ____ less fat than reference food

Fruits Grains Vegetables Proteins Dairy

Food pie chart

The terms omega-3 and omega-6 simply refer to the location of the double bonds in an unsaturated fatty acid. The specific structure of a fatty acid determines its functions in the body.

The terms ______ and _______simply refer to the location of the double bonds in an unsaturated fatty acid. The specific structure of a fatty acid determines its functions in the body.

Alpha-linolenic acid (an omega-3 fatty acid) Linoleic acid (an omega-6 fatty acid)

The two essential fatty acids

Phospholipids

They are a component of all cell membranes

Phospholipids

They are a component of lipoproteins, which transport fat in the blood

Phospholipids

They are emulsifiers (help to suspend fats in a watery environment)

Chylomicron

Triglyceride. Carries dietary fat from the small intestine to cells

VLDL

Triglyceride. Carries lipids made and taken up by the liver to cells.

Liquid

Unsaturated is _____ at room temperature

Omega 3 Alpha-linolenic acid

Walnuts Canola oil Chia seeds Flax seeds Perilla oil Hempseed oil

The terms cis and trans refer to the specific shape of an unsaturated fatty acid. When a fatty acid is unsaturated, the carbon chain is bent.

The terms _____ and _____ refer to the specific shape of an ______ fatty acid. When a fatty acid is ______, the carbon chain is bent.

Omega 6 Linoleic acid

Beef Poultry Safflower oil Sunflower oil Corn oil

For adults, fat should make up 20% to 35% of total kcal. DGAs recommend limiting saturated fat intake to 10% of total kcal. To reduce risk of cardiovascular disease, AHA recommends limiting saturated fat intake to 5% to 6% of total kcal.

For adults, fat should make up ___% to ___% of total kcal. DGAs recommend limiting saturated fat intake to ____% of total kcal. To reduce risk of cardiovascular disease, AHA recommends limiting saturated fat intake to __% to ___% of total kcal.

Because it removes lipids from the blood, HDL is called the "good" cholesterol.

High-density lipoproteins remove cholesterol from the blood vessels and return it to the liver, where it can be recycled into other lipoproteins or made into bile. Because it removes lipids from the blood, ______ is called the "good" cholesterol.

Cholesterol (produced by animals) Phytosterols (produced by plants)

Identify examples of sterols.

In cis unsaturated fatty acids, the ends of the carbon chain lie on the same side of the double bond. In nature, most unsaturated fatty acids exist in the cis form.

In ______ __________ acids, the ends of the carbon chain lie on the same side of the double bond In nature, ________ _______ fatty acids exist in the _______ form.

In trans fatty acids, the ends of the carbon chain lie on different sides of the double bond.

In _______ fatty acids, the ends of the carbon chain lie on different sides of the double bond.

In nutrition, a nutrient is essential if it cannot be made in the body; it must be consumed in the diet

In nutrition, a nutrient is _______ if it cannot be made in the body; it must be consumed in the diet

Organ meats Egg yolks Shellfish

List food sources of cholesterol. (3)

Eggs Peanuts Wheat germ Organ meats Lecithin is often added to foods (e.g., salad dressing) as an emulsifier

List food sources of phospholipids. (5)

Low-density lipoproteins deliver cholesterol to the tissues. LDLs contribute to the formation of plaque in the blood vessels, so LDL is called the "bad" cholesterol

Low-density lipoproteins deliver cholesterol to the tissues. _____ contribute to the formation of plaque in the blood vessels, so ______ is called the "bad" cholesterol

The individual fatty acids in the triglyceride may be saturated or unsaturated and may vary in length.

The individual fatty acids in the __________ may be saturated or unsaturated and may vary in length.

Lecithin

One example of phospholipids, the most common phospholipid found in the diet and in the body

HDL

Protein. Contributes to cholesterol removal from cells and, in turn, excretion of it from the body

1.) Large fat droplet 2.) Bile acid from gallbladder 3.) Lipase from pancreas 4.) Monoglycerids and long chain fatty acids turn into triglycerides 5.) Short and medium chain fatty acids enter the blood stream 6.) Triglycerides combine with cholesterol, protein, and phospholipids to make chylomicron which enter the lymphatic system

Read 5x: 1.) Large fat droplet 2.) Bile acid from gallbladder 3.) Lipase from pancreas 4.) Monoglycerids and long chain fatty acids turn into triglycerides 5.) Short and medium chain fatty acids enter the blood stream 6.) Triglycerides combine with cholesterol, protein, and phospholipids to make chylomicron which enter the lymphatic system

lipoproteins

Recall that fats are not soluble in water; ______ are the solution for transporting lipids in the watery environment of the blood.

Recognize that chylomicrons arise from the GI tract, while VLDLs, LDLs, and HDLs arise from the liver.

Recognize that chylomicrons arise from the ____, while VLDLs, LDLs, and HDLs arise from the ______.

omega-3 fatty acids

Rich food sources: fish, walnuts, canola oil, chia seeds

Omega-6 fatty acids

Rich food sources: safflower oil, sunflower oil, corn oil, beef, poultry

solid

Saturated is _____ at room temperature

omega 3, omega 6

Some people don't get enough ______ most people don't get _______

Stomach, liver, pancreas, small intestine, large intestine

Summarize the process of digestion. ______: only minor digestion of fat takes place through the action of lipase enzymes. ______: produces bile stored in the gallbladder and released through the bile duct into the small intestine. Bile acids in fat digestion and absorption by emulsifying lipids in there digestive juices. ______: secretes a mixture of enzymes, including lipase, into the small intestine. _____: the primary site for digestion and absorption of lipids. Once absorbed, long chain fatty acids are packaged for transport through the lymph and bloodstream. _____: less than 5% of indigested fat is normally excreted in the feces

Sterols are multiring structures. Some sterols have a fatty acid tail.

_____ are multiring structures. Some of them have a fatty acid tail.

Trans fatty acids are formed during food processing (e.g., hydrogenation of oils or deep frying). Trans fats are not good for heart health because they worsen blood cholesterol levels.

_____ fatty acids are formed during food processing (e.g., hydrogenation of oils or deep frying). ______ fats are not good for heart health because they worsen _____ _________ levels.

omega-3 fatty acids

________ acids: tend to decrease blood clotting, decrease inflammation, and decrease triglycerides in the blood

Triglycerides are composed of three fatty acids attached to a glycerol backbone.

________ are composed of ______ fatty acids attached to a _______ backbone.

Triglycerides are the main form of lipids in foods and in the body. The purpose of a triglyceride is to store energy.

________ are the main form of lipids in foods and in the body. The purpose of a __________ is to store energy.

Phospholipids have the unique quality of being simultaneously soluble in fat and water

________ have the unique quality of being simultaneously soluble in ____ and _____.

Saturated: contains no carbon-carbon double bonds; the fatty acid chain is fully saturated with hydrogen atoms

________: contains no carbon-carbon double bonds; the fatty acid chain is fully saturated with hydrogen atoms

Omega-6 fatty acids

_________ acids: tend to increase blood clotting and promote the inflammatory response; they also are involved in regulation of blood pressure.

Polyunsaturated

_________ fatty acids are most susceptible to rancidity.

Unsaturated: contains at least one carbon-carbon double bond (i.e., the fatty acid chain is not fully saturated with hydrogen atoms);

_________: contains at LEAST one carbon-carbon double bond (i.e., the fatty acid chain is not fully saturated with hydrogen atoms);

Polyunsaturated: contains more than one carbon-carbon double bond

_________: contains more than one carbon-carbon double bond

Monounsaturated: contains one carbon-carbon double bond

_________: contains one carbon-carbon double bond

Phospholipids are composed of two fatty acids and one phosphate-containing group bound to a glycerol backbone.

__________ are composed of two fatty acids and one phosphate-containing group bound to a glycerol backbone.

The two essential fatty acids are precursors for the synthesis of other fatty acids and important chemicals in the body that form cell membranes and function as regulators of neurological development, vision, immune function, blood clotting, and inflammation.

______________ fatty acids are precursors for the synthesis of other fatty acids and important chemicals in the body that form cell membranes and function as regulators of neurological development, vision, immune function, blood clotting, and inflammation.