Chapter 5:Lipid

Polyunsaturated Fats

Even less linear than monounsaturated Fats. Needs to be even colder to freeze. Almost always stays liquid. Corn and vegetable oils

Phospholipid Example

Lecithin

Monounsaturated Fats

Less linear. Harder to solidify in crystal. Liquid at room temperature. Olive oil and canola oil

Saturated

Linear arrangement. High melting or freezing point. Solid at room temperature. Most animal fats

Name the class of nutrients that consists of triglycerides, phospholipid, and sterols.

Lipids

Saturated Fatty Acid

Long chain of carbon atoms with each carbon bonded to two hydrogens. Carbons create single bonds.

Alpha-linolenic acid is an omega-_____ fatty acid

3

How many bonds do carbon atoms create?

4 bonds. This affects the structure.

You just ate a food item containing 5 grams of fat, which means that the food provides ________ kilocalories of fat

45; 9 calories per gram of fat

Colder Temperature and Saturation

Able to function because they are highly unsaturated. This allows things to pass through at the colder temperatures.

The main sources of saturated fat in American diets are...

Animal Fats

A diet that contains less than 10% of kcal from fat may...

Be deficient in essential fatty acids and lead to deficiencies of fat-soluble vitamins

Monounsaturated Fatty Acid

Double bond between carbons, but still four bonds. One carbon-carbon double bond

Point of Unsaturation

Double bond point. Can be broken up and attach two or more hydrogen bonds

What are some examples of foods that contain cholesterol?

Eggs, lean ground beef, turkey

Polyunsaturated Fatty Acid

More than one carbon-carbon double bond

Chemical Structure of Sterol

Multi-ringed compound with a hydroxyl group

Omega 3 and 6 Acids

Name depends on where double bonds occurs. This affects physical property. Very unsaturated

Fatty Acid Example

Omega 6 and Omega 3

3 Major Types of Lipids

Saturated, Monounsaturated, Polyunsaturated

What are the major functions of fatty acids and triglycerides in the body?

To insulate and protect the body, to aid in transport of fat-soluble vitamins, and to provide energy.

Due to their high energy density (9 kcal per gram)______ are the ideal form of energy storage for the body

Triglycerides

What is the most efficient form of stored energy for the body?

Triglycerides

Linoleic acid is an omega-____ fatty acid

6

How many calories are in one gram of fat?

9 calories per gram of fat

Trans- type of fatty acid's associated shape of carbon chain

Allows the carbon chain to remain straighter

What is the structure and function of glycerol molecules?

An alcohol containing 3 carbons; its the backbone of triglyceride molecule

Cis type of fatty acid's associated shape of carbon chain

Causes the carbon chain to bend

Cell Membranes and Saturation

Cell membranes have to permeable to let things pass through. Less saturation, the easier things can pass through the membrane

Chemical Structure of Fatty Acids

Chain of carbons flanked by hydrogens

Sterol Example

Cholesterol

Chemical Structure of Phospholipid

Glycerol backbone with fatty acids and at least one phosphorous -containing group

Fake Fats

Olestra. Non-digestible fat because lipase can't break the bonds from the backbone. Made from fatty acid on backbone of sucrose.

Compared to margarine, butter is...

Higher cholesterol, higher saturated fat

What are some of the positive attributes of fat in the diet?

Many flavors are fat soluble, so fat enhances flavor or foods. Fat is required for absorption of some vitamins. Fat improves mouth feel of foods.

List the steps of dietary fat absorption from absorption in the small intestine and ending with entrance into the lymphatic system.

1.Absorption of glycerol, monogylcerides, and fatty acids into small intestine cells. 2.Triglycerides are reassembled. 3. Triglycerides are packed into chylomicrons. 4. Chylomicrons enter the lymphatic system

Warmer Climates and Saturation

Can have higher saturation levels.

Sterols

Common type of sterol is Cholesterol. We can make our own. Found only in animal products, never in plants

The American Heart Association recommends using plant oils rather than animal fats in food preparation to...

Decrease saturated fat intake

Lipids are a diverse group of chemical compounds. Which of the following properties do all types of lipids have in common?

Do readily dissolve in water

Hydrogenated Fats

Doesn't occur in nature, but in food supply. Plant fat is made into animal fat. Double bonds are broken by bubbling hot hydrogen gas through it

Chemical Structure of Triglyceride

Glycerol backbone with 3 fatty acids

What is a Lipid?

It is soluble in organic solvents, not in water.

Which molecule contains a glycerol backbone, two fatty acids, and a phosphorous group and classified as a lipid?

Phospholipid

What are some examples of foods that are considered high in fat?

Salad oils, butter, margarine, mayo

Triglyceride Description

3 fatty acids and 1 glycerol molecule

Phospholipids

1 of the fatty acids are replaced by phosphorus containing compound. It is a part of cell signaling.

List the steps of fat digestion and absorption starting in the mouth and ending at the small intestine.

1. Some lipase is released by the salivary glands and stomach. 2. Lipase begins digesting short-chain fatty acids in the stomach 3. Bile emulsifies the fats 4. Lipase digests long-chain fatty acids and triglycerides 5. Triglycerides are broken down and absorbed in the small intestine.

Triglycerides

3 Fatty Acids on glycerol backbone. Are 98% of fats in diets are these

Problem with Fake Fats and Vitamins

Fat soluble vitamins will attach themselves and won't be absorbed by the body. The body then loses the vitamins.