CH05: Fats: Essential Energy-Supplying Nutrients

The enzyme gastric lipase, secreted in the stomach, begins the digestion of some triglycerides.

gastric lipase

Our bodies synthesize cholesterol in the liver and __________.

intestines

This enzyme, which breaks down triglycerides into monoglycerides and free fatty acids, is called pancreatic lipase.

pancreatic lipase

Which enzyme is responsible for the majority of the digestions of lipids?

pancreatic lipase

Which group of foods is a good source of polyunsaturated fats?

walnuts, corn oil, and sesame oil

Cholesterol is a lipid with a multiple-ring structure, and is an important component of cell membranes.

Cholesterol

Micelles are carriers made up of bile and phospholipids that can trap monoglycerides and fatty acids and transport digested fats from food to the enterocytes.

Micelles

Pancreas

Pancreatic lipase

When fat enters the small intestine, the gallbladder releases an emulsifier called bile to break up the large fat globules into smaller fat droplets.

bile

Which of the following foods contains primarily saturated fats?

butter

What are micelles?

clusters of fatty acids, monoglycerides, and other lipids surrounded by bile salts that transport lipids across the cell membrane of the villi

Which of the following foods is the best source of polyunsaturated fatty acid?

corn oil

The most common fat in foods are made up of three fatty acids attached to a three-carbon glycerol backbone and are called triglycerides.

triglycerides

Which of the following foods is the best source of monounsaturated fatty acids?

olive oil

Dietary Guidelines for Americans recommends that your intake of this type of fat is kept to an absolute minimum.

trans fat

Mouth

Lingual lipase

Fat is stored in __________ for later use.

adipose tissue

The gallbladder releases bile into the small intestine.

gallbladder

Stomach

1. Gastric lipase 2. Gastrin

Take a bite of pizza. -> Lipids are transported throughout the body.

1. Mechanical digestion by chewing breaks food down. 2. Lingual lipase begins chemical digestion of food. 3. Gastric lipase digests some triglycerides. 4. The gall-bladder secretes bile into the small intestine where it emulsifies fat into smaller globules. 5. With aid of pancreatic lipase, fats are further broken down into free fatty acids and monoglycerides. 6. Products of fat digestion are packaged into micelles and transported to the enterocytes. 7. Shorter fatty acids enter the bloodstream for transport, and chylomicrons are released into lymph vessels.

Small intestine

1. Micelles 2. Cholecystokinin

Gallbladder

Bile

Which of the following statements describes the nature of emulsification?

Bile salts act to emulsify lipids in the small intestine, which helps pancreatic lipase access fats for further digestion.

Most of the triglycerides in food reach the stomach without being chemically digested.

True

An example of a compound synthesized from cholesterol is __________.

vitamin D

The recommended intake of saturated fats is less than __________ of total energy intake.

10%

Triglycerides consist of __________ fatty acids attached to a glycerol backbone.

3

Fat provides __________ kcals of energy per gram.

9

A meal containing 10 g of fat provides __________ kcal from fat.

90

Chylomicrons are lipoproteins produced in the enterocyte that carry fats and cholesterol from the intestine through the lymph system and to the bloodstream.

Chylomicrons

Fat is digested and absorbed by the same process that digests and absorbs carbohydrates and proteins.

False

Foods contain only one type of fatty acid, either saturated or unsaturated, but never both.

False

Lipids enter the bloodstream directly after digestion.

False

Which of the following statements is false?

Fats are nonessential nutrients.

Which type of fatty acid is most common in animal-based foods, such as steak, butter, and milk?

saturated fat

Lecithins are phospholipids that are used to make bile.

Lecithins

In a saturated fatty acid, every carbon atom is saturated with __________.

hydrogen

To increase intake of omega-3 fatty acids, include fish, canola oil, ground flax seeds, or __________ in your diet.

walnuts