Deck 6: Lipids

Question 1

Trans fatty acids are naturally abundant in avocados.

Answer 1

False

Question 2

In general, animal foods supply the majority of dietary saturated fatty acids and plant-based foods supply the majority of polyunsaturated fatty acids.

Answer 2

True

Question 3

Dietary recommendations for reducing cardiovascular disease risk include lowering saturated and trans fatty acid intake to as minimal an amount as possible.

Answer 3

False

Question 4

A fatty acid that contains only carbon-carbon single bonds is called

A) a saturated fatty acid.
B) an unsaturated fatty acid.
C) a monounsaturated fatty acid.
D) a polyunsaturated fatty acid.

Question 5

Good food sources of both essential fatty acids are

A) meats.
B) eggs.
C) vegetable oils.
D) milk products.

Question 6

Lipoprotein lipase only releases free fatty acids from chylomicrons.

Question 7

The most abundant sterol in the body is cholesterol.

Question 8

Linoleic and linolenic acid

A) are both 16 carbons long.
B) are both omega-3 fatty acids.
C) are both essential fatty acids.
D) contain 2 double bonds each.

Question 9

All lipoproteins have similar structural components but differ in size and density.

Question 10

The formation of triglycerides is called

A) lipolysis.
B) lipogenesis.
C) β-oxidation.
D) fatty acid synthesis.

Question 11

Eicosanoids are hormone-like compounds produced from

A) saturated fatty acids.
B) the essential fatty acids.
C) omega-3 fatty acids.
D) omega-6 fatty acids.

Question 12

Fatty acids are the most abundant lipid molecules in the body.

Question 13

The essential fatty acids are linoleic acid and linolenic acid.

Question 14

Trans fatty acids are produced commercially through the process of

A) hydrogenation.
B) partial hydrogenation.
C) transesterification.
D) transamination.

Question 15

A fatty acid with the name: cis9, cis12, cis15-18:3 has

A) 18 carbons and 3 cis double bonds.
B) 18 carbons and 9 cis double bonds between carbons 15 and 18.
C) 15 carbons and 3 cis double bonds.
D) Cis double bonds at every third carbon.

Question 16

The most abundant lipids in the human body are

A) fatty acids.
B) triglycerides.
C) cholesterol molecules.
D) phospholipids.

Question 17

Triglycerides and phospholipids are structurally similar.

Question 18

Omega-6 eicosanoids are associated with

A) increased inflammation.
B) relaxation of blood vessels.
C) inhibition of blood clotting.

Question 19

Cardiovascular disease risk is solely attributable to dietary fat intake.

Question 20

The removal of fatty acids from the glycerol backbone is called

A) lipolysis.
B) lipogenesis.
C) β-oxidation.
D) fatty acid removal.

Question 21

Unsaturated fatty acids tend to be liquid at room temperature, while saturated fatty acids are usually solid at room temperature. The explanation for this difference is that

A) saturated fatty acids have a rigid structure that allows them to pack densely, making them solid at room temperature.
B) unsaturated fatty acids are usually short-chain fatty acids and therefore are usually oils.
C) double bonds are stabilized at room temperature, resulting in oil formation.
D) double bonds are destabilized at room temperature, resulting in more random movement of fatty acids in oils.

Question 22

Concerns about the health effects of trans fatty acid consumption have led to

A) the requirement for trans fat content to be listed on the Nutrition Facts panel of packaged foods.
B) a ban on partial hydrogenation in the food industry.
C) recalls of many trans fatty acid-containing foods such as crackers.
D) no changes in the food or health care industries.

Question 23

The primary function of HDL particles is to

A) deliver fatty acids to cells.
B) deliver cholesterol to cells.
C) deliver fatty acids to the liver.
D) pick up cholesterol from nonliver cells and deliver it to the liver.

Question 24

Cells take up LDL particles

A) using lipoprotein lipase.
B) using the LDL receptor.
C) by simple diffusion.
D) using the insulin receptor.

Question 25

Lipoproteins all have similar structures. The outer surface of all lipoproteins consists of phospholipids, cholesterol, and at least one special protein called

A) an apolipoprotein.
B) a lipid transport protein.
C) a lipo-protein.
D) an activating protein.

Question 26

The 2010 Dietary Guidelines for Americans and the American Heart Association both recommended that adults consume less than _____ mg of cholesterol each day.

A) 100
B) 200
C) 300
D) 500

Question 27

The primary function of LDL particles is to

A) deliver fatty acids to cells.
B) deliver cholesterol to cells.
C) deliver fatty acids to the liver.
D) pick up cholesterol from nonliver cells and deliver it to the liver.

Question 28

The metabolic breakdown of fatty acids to produce ATP is called

A) lipolysis.
B) lipogenesis.
C) β-oxidation.
D) fatty acid burning.

Question 29

The Acceptable Macronutrient Distribution Range (AMDR) for lipids is

A) <30% of total energy intake.
B) 10-35% of total energy intake.
C) 20-35% of total energy intake.
D) 45-65% of total energy intake.

Question 30

Micelles are

A) small droplets of bile released into the duodenum from the gallbladder.
B) small droplets of dietary cholesterol that move rapidly through the intestinal tract.
C) small droplets of fat resulting from emulsification of large droplets that come from the stomach.
D) small droplets of triglycerides that have reformed from the fatty acids and diglycerides produced by lipase activity.

Question 31

Chylomicrons are released into the _____ for transport.

A) blood
B) lymphatic circulation
C) lumen of the intestine
D) cytoplasm of the cell

Question 32

What hormone instructs the gallbladder to release bile into the duodenum?

A) Gastrin
B) Cholecystokinin
C) Secretin
D) Bile-releasing hormone

Question 33

The enzyme lipoprotein lipase releases fatty acids from chylomicrons, so they can be taken up by surrounding cells. What remains of the chylomicron is called

A) a low-density lipoprotein.
B) a high-density lipoprotein.
C) an intermediate-density lipoprotein.
D) a chylomicron remnant.

Question 34

Short-chain fatty acids are usually liquid at room temperature while long-chain fatty acids are usually solid at room temperature. The explanation for this difference is that

A) chain length affects the temperature at which a fatty acid melts.
B) chain length affects water solubility.
C) chain length is modified by room temperature.
D) short-chain fatty acids generally have more double bonds than long-chain fatty acids.

Question 35

Cholesterol-rich low-density lipoproteins (LDL) are produced

A) in the liver.
B) in the small intestine.
C) in the blood by continued removal of fatty acids from IDL particles.
D) in the blood by continued cholesterol pick-up by HDL particles.

Question 36

The organization of hydrogen atoms around the double bond is called _____ when they are on the same side as the double bond, and _____ when they are on opposite sides of the double bond.

A) same, opposite
B) cis, trans
C) trans, cis
D) sister, brother

Question 37

Triglyceride digestion begins in the mouth because of the activity of

A) salivary amylase.
B) lingual lipase.
C) gastric lipase.
D) pancreatic lipase.

Question 38

Chylomicron remnants are taken up into the _____, where their contents are reused or recycled.

A) liver
B) kidneys
C) pancreas
D) adipose tissue

Question 39

Phospholipids and sterols

A) are essential nutrients.
B) are important component of cell membranes.
C) block transport of lipids in the blood.
D) are derived from steroid hormones.

Question 40

Fatty acids are distinguished from one another by their chain length and

A) the presence of an alpha end with a carboxylic acid group.
B) the presence of an omega end with a methyl group.
C) the number and positions of double bonds within the molecule.
D) the presence of nitrogen in the carbon chain.

Question 41

The density of lipoproteins is determined by the relative amounts of

A) long-chain and short-chain fatty acids.
B) phospholipids and triglycerides.
C) triglycerides and cholesterol.
D) lipids and proteins.

Question 42

Functions of cholesterol include all of the following except:

A) It is a precursor for bile acids, which are important in lipid digestion.
B) It is used to synthesize reproductive hormones such as testosterone and estrogen.
C) It is incorporated into cell membranes, where it helps maintain flexibility.
D) It is used for energy production when fatty acids are in short supply.

Question 43

In an omega-3 fatty acid of any chain length the first double bond is

A) between the third and fourth carbons counting from the omega (methyl) end of the molecule.
B) between the third and fourth carbons counting from the alpha (carboxylic acid) end of the molecule.
C) between the sixth and seventh carbons counting from the omega (methyl) end of the molecule.
D) in a trans configuration.

Question 44

Lipids in micelles are taken up by intestinal cells, where

A) the long-chain fatty acids are released into the bloodstream to bind to albumin for transport.
B) the fatty acids and monoglycerides are reassembled into triglycerides and incorporated into chylomicrons for transport.
C) the fatty acids and monoglycerides are reassembled into triglycerides and incorporated into VLDL particles for transport.
D) the cholesterol and phospholipids are converted to triglycerides and incorporated into chylomicrons for transport.

Question 45

In addition to promoting glucose uptake into cells, insulin

A) promotes triglyceride storage during times of energy excess.
B) promotes lipolysis.
C) promotes β-oxidation.
D) promotes ketogenesis.

Question 46

High intakes of saturated fatty acids, trans fatty acids, and _____ are associated with increased risk of cardiovascular disease in certain people.

A) monounsaturated fatty acids
B) cholesterol
C) phytosterols
D) lecithin

Question 47

One advantage of storing excess energy as triglycerides as compared to storing it as glycogen is that

A) triglycerides are stored with water, creating the perfect environment for chemical reactions to release energy.
B) one gram of triglycerides contains over twice the amount of energy as one gram of carbohydrate.
C) one gram of triglycerides contains over twice the amount of energy as one gram of protein.
D) triglyceride storage in the liver makes energy readily available for this highly active organ.

Question 48

Rather than cholesterol, plants produce cholesterol-like compounds called phytosterols. Phytosterols have been shown to

A) substitute for cholesterol in the human body.
B) be readily absorbed in the human body.
C) lower blood cholesterol levels through unknown mechanisms.
D) be readily incorporated into cell membranes in the human body.

Question 49

Short- and medium-chain fatty acids

A) are taken up by intestinal cells without the aid of micelles.
B) are incorporated into micelles in order to be taken up by intestinal cells.
C) must be incorporated into chylomicrons to leave the intestinal cell.
D) are used by the intestinal cells and then excreted.

Question 50

Monoglycerides, diglycerides, and triglycerides are distinguished from one another by

A) the number of fatty acids attached to the glycerol backbone.
B) the types of fatty acids attached to the glycerol backbone.
C) the length of the fatty acids attached to the glycerol backbone.
D) the saturation of the fatty acids attached to the glycerol backbone.

Question 51

Excess dietary fatty acids that are not required for energy production or other functions are

A) converted to amino acids for protein synthesis.
B) stored as triglycerides in adipose tissue.
C) transported in the blood as free fatty acids until they are needed.
D) excreted in the feces.

Question 52

Adipose tissue plays an important insulating role in the body. People with minimal adipose tissue

A) have difficulty regulating body temperature and therefore have difficulty staying warm.
B) do not benefit from the cooling effects of adipose tissue.
C) cannot mount any physiological responses to compensate for their lack of adipose tissue.
D) rely on natural day-to-day fluctuations in the amount of adipose tissue to provide insulation.

Question 53

Under certain conditions, such as starvation, fatty acids can be used to form

A) ketones, an alternative energy source for some tissues.
B) amino acids so that protein synthesis can continue to occur.
C) glucose so that the brain can function normally.

Question 54

During infancy, the ability to process the essential fatty acids to other fatty acids such as arachidonic acid and DHA may be impaired due to immature production of the required enzymes. In this situation, arachidonic acid and DHA are considered

A) dispensable.
B) nonessential.
C) conditionally essential.
D) provisionally essential.

Question 55

The products of pancreatic lipase acting on a triglyceride molecule are

A) a monoglyceride and two free fatty acids.
B) a diglyceride and one free fatty acid.
C) a glycerol backbone and three free fatty acids.
D) None of the above; pancreatic lipase only acts on diglycerides.