Lipids

Question 1

lipid

Answer 1

hydrophobic compound of C, H, and O

Question 2

fatty acids

Answer 2

most basic units of triglycerides and phospholipids

consist of C chains 2-80 C in length

Question 3

basic structure of fatty acids

Answer 3

carboxylic acid group at alpha end
carbon chain
methyl group at omega end

Question 4

short chain fatty acids

Answer 4

less than 8 carbons long

Question 5

medium chain fatty acids

Answer 5

8-12 carbons long

Question 6

long chain fatty acids

Answer 6

12+ carbons long

Question 7

how does fatty acid chain length affect how we absorb, digest, and metabolize fatty acids?

Answer 7

long chain takes longer to digest/absorb

shorter chains are more H2O soluble

Question 8

rancidity

Answer 8

when oxidized, foods containing fatty acids may develop bad smell/taste
H is extracted from fatty acid chain, and becomes a free radical (unpaired electron)
free radical makes fatty acid unstable, so O attaches to free electron

Question 9

unsaturated fats are (more/less) likely to becomes rancid

Answer 9

more; double bonds are less stable

Question 10

how to decrease rancidity

Answer 10

limit foods exposure to oxygen, heat. and light

Question 11

hydrogenation

Answer 11

adding H to unsaturated fatty acid to make it more saturated and solid at room temp; aids in stabilization

Question 12

omega 3 fatty acids

Answer 12

family of PUFA with first double bond between 3rd and 4th carbon from omega end

Question 13

omega 6 fatty acid

Answer 13

family of PUFA with first double bond between 6th and 7th C from omega end

Question 14

cis fatty acids

Answer 14

configuration where both H are on same side of double bond

more common in nature

Question 15

trans fatty acids

Answer 15

configuration where each H are on opposite sides of double bond
found naturally not so often, just in milk and meat
mostly made during hydrogenation

Question 16

triglyceride

Answer 16

3 fatty acids+glycerol backbone
most common type of lipid found in foods
aka ‘fat’
usually contains mix of fatty acids

Question 17

phospholipids

Answer 17

2 fatty acids + phosphate group + glycerol backbone
type of lipid
also include a N containing group at head to make head hydrophilic/polar

Question 18

lecithin

Answer 18

phospholipid made in body

integral to structure of cell membranes

Question 19

emulsifier

Answer 19

compound that keeps 2 incompatible substances mixed together

Question 20

sterols

Answer 20

type of lipids that contains 4 connecting rings of C and H
cholesterol is most common
do not contain glycerol or fatty acids
do not provide energy

Question 21

cholesterol

Answer 21

4 ring sterol and hydrocarbon tail on one end, hydroxyl on other
found only in animal products

Question 22

kind of sterols most often found in plants

Answer 22

phytosterols and phytostanols

Question 23

general fat digestion process

Answer 23

lipases remove fatty acids from glycerol backbone by hydrolysis
absorb fat through small intestine and transport by lipoproteins

Question 24

digestion of fats in mouth

Answer 24

mastication mainly, and warming of solid fats

no digestive enzymes for fats

Question 25

digestion of lipids in stomach

Answer 25

where digestion really starts | gastric lipase turns triglycerides to diglycerides and free fatty acids

Question 26

small intestine fat digestion

Answer 26

mostly occurs here bile goes into duodenum and emulsifies fat pancreatic lipase hydrolyzes triglycerides phospholipase hydrolyze phospholipids products are then brought into enterocytes via micelles

Question 27

how are glycerol and short/medium chain fatty acids absorbed

Answer 27

absorbed directly into bloodstream through mucosa of small intestine; to portal vein; to liver

Question 28

how are long chain fatty acids and monoglycerides absorbed

Answer 28

they must be reassembled in enterocyte, free long chain fatty acids reattach to monoglycerides and combine with career proteins to form chylomicron

Question 29

chylomicron

Answer 29

type of lipoprotein that carries digestive fat and other lipids through lymph system to blood

Question 30

lipoprotein lipase (LPL)

Answer 30

enzyme that hydrolyzes triglycerides in lipoproteins into 3 fatty acids and glycerol

Question 31

very low density lipoproteins

Answer 31

deliver fat made in liver (triglyceride and cholesterol) to tissues remnants are converted to LDL

Question 32

LDL

Answer 32

deposit cholesterol in artery walls; can lead to heart disease; formed from VLDL

Question 33

HDL

Answer 33

remove cholesterol from tissues and deliiver it to liver to be used as part of bile and/or excreted from body made from cholesterol gathered in tissues and arterial walls

Question 34

components of lipoprotein

Answer 34

lipid center, phospholipid/protein shell

Question 35

essential nutrients that require dietary fat to be absorbed

Answer 35

vitamins A, D, E, K, cholesterol, phospholipids, carotenoids

Question 36

___ of dietary fat needed per day to stimulate formation of chylomicrons

Answer 36

20g

Question 37

linoleic and alpha linolenic acid needed for precursors to form _____

Answer 37

eicosanoids

Question 38

eicosanoids

Answer 38

hormone like structure in body that regulates immune system, blood clotting, inflammation, and BP prostaglandins, thromboxjnes, leukotrines

Question 39

arachidonic acid

Answer 39

omega 6 fatty acid formed from linoleic acid | used to synthesize eicosanoids

Question 40

key role of cholesterol

Answer 40

serve as starting material in synthesis of steroid hormones

Question 41

AMDR for fat

Answer 41

20-35%

Question 42

T/F diet higher in fats but lower in kcal is still good

Answer 42

true

Question 43

saturated fat recommendation per day for heart health

Answer 43

<10%

Question 44

AI for linoleic acid in men; in women

Answer 44

17g/day; 12g/day

Question 45

AMDR for linoleic acid

Answer 45

5-10%

Question 46

AI for alpha linolenic acid in men; in women

Answer 46

1.6g; 1.1g

Question 47

how much essential fatty acids should people with heart disease consume per day

Answer 47

around 1g

Question 48

T/F we should eat as little dietary cholesterol as possible

Answer 48

true

Question 49

trans fats increase ____ and ___ level; decrease ___ level

Answer 49

LDL and triglyceride; HDL

Question 50

carb-based fat substitutes

Answer 50

most fat substitutes | use plant polysaccharides to retain moisture and catlike texture

Question 51

protein-based fat replacements

Answer 51

created from protein in eggs and milk | break down under high temp

Question 52

fat-based fat replacement

Answer 52

modified fats that either mimic fat for lower calories, or block fat absorption mono or diglycerides used as emulsifiers same cal/gram but you use less

Question 53

olestra

Answer 53

fat substitute thats a mix of sucrose and long chain fatty acids

Question 54

most common type of cardiovascular diseaes

Answer 54

coronary heart diseaes