Mod 7 Lipids

Question 1

What kind of molecule is a lipid

Answer 1

A molecule that is partly or entirely hydrophobic (hates water)

Question 2

What are the four kinds of lipids we are covering in this chapter?

Answer 2

1 triglycerides
2 sterols
3 phospholipids
4 fatty acids

Question 3

Describe the structure of phospholipids

Answer 3

phospholipids have a glycerol backbone and 3 fatty acid projections attached to it.

Question 4

What are the three main ways lipids can be catergorized?

Answer 4

1- length
2- degree of saturation
3- geometric (molecular) organization

Question 5

Describe the molecular structure of a fatty acid chain

Answer 5

long chains of carbon and hydrogen atoms –a Hydrocarbon Chain

Question 6

What is an atom?

Answer 6

A SINGLE, neutral particle (remember: molecules are two or more particles)

Question 7

What differentiates saturated vs unsaturated fatty acids?

Answer 7

UNsaturated Fatty Acids have one or more DOUBLE BONDS in their chains

Question 8

Structure dictates function: this is a fundamental rule of _____

Answer 8

Nature –applies to the structures of saturated and unsaturated fatty acids- one small difference makes all the difference

Question 9

Fatty Acids with ONE double bond are

Answer 9

MONOsaturated fatty acids (mono=1)

Question 10

Omega-3 fatty acid is also called

Answer 10

alpha-linolenic acid

Question 11

Omega-6 fatty acid is also called

Answer 11

linolenic acid

Question 12

Two fatty acids are essential for humans (and were once called “vitamin F”)

Answer 12

Omega-3 & Omega-6 (alpha-linolenic and linolenic acid)

Question 13

What two seeds have high amounts of omega-3 / alpha linolenic acid

Answer 13

chia and flax

Question 14

what foods have high amounts of docosahexaenoic acid

DHA) and eicosapentaenoic acid (EPA

Answer 14

fish, fish oil, lamb and beef.

Question 15

omega-3 can be used to synthesize two other essential fatty acids )

Answer 15

docosahexaenoic acid
(DHA) and eicosapentaenoic acid (EPA

Question 16

Eicosanoids

Answer 16

signaling molecules that omega-3 and 6 fatty acids can be used to synthesize.

Question 17

Long chain fatty acids (how many carbons)

Answer 17

14 or more

Question 18

A source of long chain fatty acids

Answer 18

meats

Question 19

A source of medium chain fatty acids

Answer 19

cooking oils, like coconut oil

Question 20

Where do short chain fatty acids come from?

Answer 20

Fiber from plant matter, it is fermented by bacteria in the large intestine.

Question 21

unsaturated fatty acids can be two types

Answer 21

CIS or TRANS

Question 22

In a CIS unsaturated fatty acid, where are the hydrogen atoms

Answer 22

Hydrogens are on the same side of the double bond –creates a small kink in the chain

Question 23

In a TRANS unsaturated fatty acid, where are the hydrogen atoms

Answer 23

Hydrogens are on the opposite side of the double bond -creates no kink in the chain, structurally they more closely resemble a saturated fatty acid

Question 24

Hydrogenation

Answer 24

the process through which food industry converts cis-unsaturated fatty acids into trans-unsaturated fatty acids (enhanced stability; longer shelf life)

Question 25

the cell membrane is primarily made up of

Answer 25

phospholipids

Question 26

To synthesize vitamin D, the body needs:

Answer 26

cholesterol

Question 27

structurally, what is the main difference between a cis and trans fatty acid ?

Answer 27

the location of the hydrogen atoms at the double bond

Question 28

What is the best source of short-chain fatty acids?

Answer 28

fiber rich foods

Question 29

Phospholipids have __ (#) of fatty acids in their structure

Answer 29

TWO

Question 30

Describe the molecular structure of Sterol group lipids

Answer 30

ring formation with a hydrocarbon chain

Question 31

What roles do sterol lipids play in the body?

Answer 31

They provide structure to cell membranes

Question 32

The most common animal-derived sterol?

Answer 32

Cholesterol

Question 33

Cholesterol is important to the body, but not considered an essential nutrient–why?

Answer 33

The liver (and other body tissues) can synthesize their own cholesterol

Question 34

What are phytosterols

Answer 34

Plant derived sterols ..cooking oils are a large source of this . also found in fruits, seeds and nuts.
–however, when oils are refined, the concentration of phytosterols lowers

Question 35

What lipids are Critical components of every human cell membrane?

Answer 35

Phospholipids! –the phospholipid bilayer

Question 36

What is so special about the phospholipid bilayer membrane of our cells?

Answer 36

Only water and non-polar substances can readily pass through the membrane, other substances need a transporter (allows for tight regulation of contents). This allows the water content inside the cell to be fully separated from the water content outside the cell.

Question 37

Why are phospholipids important in the food industry?

Answer 37

they help form emulsions

Question 38

Lipid digestion begins in the mouth with the release of

Answer 38

lingual lipase

Question 39

Describe lipid digestion in the stomach

Answer 39

The gastric acid of the stomach deactivates lingual lipase, but lipid digestion continues here because the stomach secretes gastric lipase

Question 40

What kinds of fatty acid chains are lingual and gastric lipase most important for?

Answer 40

small and medium-chain fatty acids, and these enzymes work to begin lipid digestion.

Question 41

Most lipid digestion occurs in the small intestine with two important molecules

Answer 41

1- bile, it emulsifies larger lipids into smaller ones

2- Pancreatic lipase further breaks down lipids into smaller components

Question 42

Bile is important for lipid digestion, where is it 1) produced , 2) stored

Answer 42

1) produced in the liver

2) stored in the gallbladder

Question 43

When bile emulsifies lipids, a structure is formed around the lipids called

Answer 43

a MICELLE- lipids in the center, bile salts surrounding

Question 44

Lipids are absorbed through the process of

Answer 44

passive diffusion

Question 45

Chylomicrons, LDL, VLDL and HDL are all:______

Answer 45

lipoproteins