Chapter 6: Fats/Lipids
What is a triglyceride?
A molecule consisting of three fatty acids bonded to a glycerol.
The hormones that stimulate the gallbladder to release bile and the pancreas to release digestive enzymes is called:
cholecstoskinin
A lipid found only in foods that contain animal products is:
cholesterol
Although _______ is not metabolized for energy, cells use the lipid to synthesize a variety of substances, including vitamin D, and steroid hormones such as estrogen and testosterone
cholesterol
how many kilocalories are in one gram of fat?
9
Primarily, fatty acids are transported through the bloodstream . . .
as part of lipoproteins
Most cases of heart disease and stroke result from:
atherosclerosis
Phospholipids contain a ______ portion, which attracts water, and a ____ portion, which repels water.
hydrophilic , hydrophobic
True or false: Phospholipids are only found in fat cells
False
Chylomicrons are too large to be absorbed directly into the bloodstream and must pass through the larger opening of _____, which are lymphatic system vessels in each villus.
lacteals
_____ is a common example of a phospholipid
Lecithin
Glycerol and fatty acids are both by-products of ________ digestion
lipid
Where is bile made?
Liver
What enzyme breaks down triglycerides into free fatty acids and glycerol in the bloodstream?
lipoprotein lipase
Manufactures add plant sterols to certain foods because they may:
lower blood cholesterol
____________ is a digestive enzyme that removes fatty acids from each triglyceride molecule.
Pancreatic Lipase
A lipid compound containing a multi-ring structure is a(n):
Sterols
Which of the following substance are types of lipids?
Triglycerides and cholesterol
The main product of lipid digestion is:
monoglycerides
Which of the following are leading sources of fat in the Mediterranean diet?
olive oil and fish
Saturated and trans fatty acids tend not to fo rancid because they are less likely to undergo ____ chemical process that alters the compounds structure.
oxidation
Glycerol, fatty acids, monoglycerides, cholesterol, and phospholipid fragments are all products of lipid digestion that occurs in the
small intestine
Cholesterol lowering margarines contain plant ____, which may lower cholesterol in people with mildly elevated cholesterol levels.
sterols
Glycerol, fatty acids, monoglycerides, cholesterol and phospholid fragments are all end products of lipid digestion that occurs in the:
small intestine
_________ are a type of prescription drug that reduces a persons elevated blood lipid levels.
statins
What are the functions of cholesterol?
- Synthesis of certain bile acids - Incorporation into cell structures - Synthesis of certain hormones
What are the functions of phospholipids in the body?
- form lipid bilayer of cell membranes - necessary for normal nerve function
What are the products of fat digestion in the small intestine?
- monoglycerides - glycerol - fatty acids
Soluble fibers lowers blood cholesterol by:
- reducing cholesterol absorption - interfering with bile absorption - disrupting enterohepatic circulation
What are some good food sources of phospholipids?
- wheat germ - peanut butter - soy beans
_______ cells, which remove fatty acids and glycerol form the blood and resemble them as triglycerides for storage, are commonly called fat cells.
Adipose
What is one characteristic that lipids found in foods and in the body have in common?
They are mostly in the form of triglycerides.
Manufacturers often add _____ to foods to keep oily and watery ingredients from separating during storage. Salad dressings and ice cream are two types of food that contain these agents.
emulsifiers
What are the by-products of phospholipid digestion?
glycerol, fatty acids, and phosphorous compounds
Chylomicrons are transported in the lymphatic system to the _____ duct, where they enter the bloodstream through the left ______ ______ in the chest.
thoracic, subclavian vein
hydrogenation process produces . . .
trans fats
A _____ has three fatty acids attached to glycerol.
triglyceride
Excess protein, carbohydrates, and alcohol can all stimulate the production of _____ which leads to excess body fat accumulation.
triglycerides
Fats are not soluble in:
water
True or false: cholesterol cannot be synthesized by the body.
False
__________, a commonly prescribed class of drug, interfere with the livers metabolism of cholesterol, effectively reducing LDL cholesterol and triglyceride levels.
Statins
Which of the following can enter the bloodstream directly after being absorbed?
short and medium fatty acid chains
_______ transport lipids from the small intestine and liver to body tissues.
Lipoproteins
Where are the small cholestrol-rich remnants of chylomicrons cleared form the bloodstream and used to synthesize new lipids and other lipoproteins?
Liver
What helps enhance the digestion and absorption of lipid by keeping lipids dispersed in small particles, increasing their surface area?
Bile salts
Enterohepatic circulation is responsible for:
recycling bile from the intestinal tract
Interfering with enterohepatic circulation can __________ blood cholesterol levels because the liver muse use cholesterol to make new bile salts.
reduce