Chapter 5 Flashcards
(94 cards)
1
Q
Q: What are the 3 main types of lipids?
A
A: Triglycerides, phospholipids, and sterols.
2
Q
Q: What process forms triglycerides?
A
A: Condensation that combines hydrogen from glycerol and hydroxyl from fatty acid (glycerol + 3 fatty acids).
3
Q
Q: What type of lipid acts as an emulsifier and is found in lecithin?
A
A: Phospholipids.
4
Q
Q: Which fat is solid at room temp: butter or olive oil?
A
A: Butter (saturated fat).
5
Q
Q: What are essential fatty acids?
A
A: Linoleic acid (omega-6) and alpha-linolenic acid (omega-3).
6
Q
Q: What do omega-3s convert into?
A
A: EPA and DHA.
7
Q
Q: What are the effects of EPA-based eicosanoids?
A
A: Anti-inflammatory, anti-clotting.
8
Q
Q: Which lipoprotein is considered “good” cholesterol?
A
A: HDL.
9
Q
Q: What triggers bile release?
A
A: CCK (cholecystokinin).
10
Q
Q: What are micelles?
A
formed from monoglycerides and long chain fatty acids
Emulsified fat droplets that deliver lipids to intestinal cells by diffusing them through intestinal wall then reassembling into triglycerides
11
Q
Q: What is the main digestive enzyme for fats?
A
A: Pancreatic lipase.
12
Q
Q: What is hydrogenation?
A
A: Adding hydrogen to unsaturated fats to make them more solid/stable.
13
Q
Q: What fats raise LDL most?
A
A: Saturated and trans fats.
14
Q
Q: What is the kcal value of 1g fat?
A
A: 9 kcal.
15
Q
Q: How much total fat (g) in a 2500 kcal diet @ 30% fat?
A
A: 83 grams (2500 x 0.30 = 750 kcal ÷ 9 = 83g).
16
Q
- Which lipoprotein transports cholesterol from tissues back to the liver?
A. LDL
B. HDL
C. VLDL
D. Chylomicrons
A
B high density lipoprotein
17
Q
- What is the main function of bile in fat digestion?
A. Digests triglycerides
B. Converts FA to glucose
C. Emulsifies fats
D. Transports fats to liver
A
C
18
Q
- What type of fat is found in olive oil and is most heart-healthy?
A. Trans fat
B. Saturated fat
C. MUFA
D. PUFA
A
C
19
Q
- Which essential fatty acid is an omega-3?
A. Linoleic acid
B. Arachidonic acid
C. Alpha-linolenic acid
D. Stearic acid
A
C
20
Q
- What’s the kcal value of 15g of fat?
A. 45
B. 90
C. 135
D. 60
A
C
21
Q
- Which fat is most prone to oxidation?
A. MUFA
B. PUFA
C. SAFA
D. Trans fat
A
B
22
Q
- What triggers gallbladder contraction during digestion to release bile?
A. Secretin
B. CCK
C. Gastrin
D. Insulin
A
B
23
Q
- What’s the fate of long-chain fatty acids after absorption?
A. Sent to the liver directly
B. Packaged into micelles and stored
C. Packaged into chylomicrons and enter lymph
D. Converted to glucose
A
C
24
Q
- What percentage of dietary fat is typically absorbed?
A. 75%
B. 90%
C. 98%
D. 50%
A
C
25
10. What does hydrogenation do to fats?
A. Makes them liquid
B. Increases rancidity
C. Converts cis to trans
D. Decreases LDL
C
26
12. What type of lipid is most abundant in food and the body? specifically 95% of the fat in foods and the body?
A. Phospholipids
B. Sterols
C. Triglycerides
D. Trans fats
C
27
13. What type of fat is liquid at room temperature?
A. Saturated
B. Monounsaturated
C. Hydrogenated
D. Trans fat
B
28
15. What transports lipids from the intestine to the blood?
A. LDL
B. VLDL
C. HDL
D. Chylomicrons
D
29
16. Which fatty acids are essential?
A. Omega-3 and omega-6
B. Saturated and trans
C. MUFA and PUFA
D. Stearic and oleic acid
A
30
17. What is the function of bile?
A. Emulsify fat
B. Hydrolyze fat
C. Store fat
D. Transport fat
A
31
18. What lipoprotein is known as "bad" cholesterol?
A. LDL
B. HDL
C. VLDL
D. Chylomicrons
A low density lipoprotein
32
19. Which fat raises LDL the most?
A. PUFA
B. MUFA
C. Trans fat
D. Omega-3
C
33
21. What is the AMDR for fat?
A. 10–20%
B. 20–35%
C. 30–45%
D. 40–60%
B
34
22. What does the Mediterranean diet emphasize?
A. High saturated fat
B. High red meat
C. Olive oil, fish, nuts
D. Low-fat dairy only
C
35
lipid definition and characteristics
organic carbon-containing compound
soluble in organic solvents, not water
most are a mix of SAFA, MUFA, PUFA
36
difference between fats and oils
fat: lipid solid at room temp (25 C or 70 F)
oil: lipid liquid at room temp
37
how much storage is in the triglyceride as energy?
unlimited storage form of energy
38
adipose tissue
stores fat
secretes hormones (adipokines) regulate energy balance & body functions
too little or much of body fat changes secretions of adipokines
ex. leptin, adiopnectin, resistin
39
what is the percent of lipids in the diet that are major in cell membranes and which lipids?
phospholipids & sterols
5%
40
how does phospholipids differ from tryglycerides?
have a phosphorus (acid instead of one of the fatty acids)
soluble in both water and fat due to fatty acids and phosphorus
41
how does the food industry mix fat in mayo and chocolate bars?
using phospholipids as emulsifiers
42
what does too much phospholipids do to the body? How do you develop too much?
GI distress, sweating, loss of appetite
liver makes all lecithin a person needs
43
what is lecithin?
type of phospholipid found in veg oil
1 glycerol, 2 fatty acid chains, 1 chain phosphate, molecule of choline
44
sterols at the atomic level
interconnected rings of C atoms with side chains of C, H, O attached
45
why are sterols important?
vitamin D, sex, bile acids, hormones
cholesterol (animal product) phytosterols (plants)
rich plant diet lower blood cholesterol
cell membranes
metabolism
46
what is meant by "good" cholesterol?
way body transports cholesterol in blood
47
cholesterol types
*Endogenous: cholesterol made in the body
*Exogenous: cholesterol from outside the body
48
cholesterol and the way it is used to make bile
splits fatty acids from glycerol
liver makes 800-1500mg cholesterol a day
more than 90% body's cholesterol in cells
49
what happens from too much cholesterol?
can form plaque in artery walls, plaque deposits lead to atherosclerosis
50
what raises LDL blood cholesterol more than food cholesterol?
high SFA and trans FA from foods
51
what does high blood cholesterol indicate?
risk of CVD
52
difference between saturated fatty acids (SAFA) and the unsaturated fatty acids of monounsaturated (MUFA) and polyunsaturated (PUFA)
SAFA: no double bonds
each carbon has hydrogen atoms and single bonds
unsaturated: double bond between 2 carbon
MUFA: 1 double bond, lacking 2 Hydrogen (oleic acid - olive oil)
PUFA: 2 or more double bonds (linoleic acid - veg oil)
53
what are the 2 types of polyunsaturated fatty acids?
omega 3 & 6
54
which acids belong to SUFA, MUFA, and PUFA?
SUFA: stearic acid (steer like cow)
MUFA: oleic acid (olive oil)
PUFA: linoleic acid (veg oil)
55
what does the location of unsaturation determine?
unsaturated: double bond
how fatty acids named
counting # carbs from methyl end (CH3) to acid end
56
what is the omega-9?
MUFA
57
where do fatty acids rarely occur?
free in foods
often in triglycerides
58
shorter chain saturated fats are...
mostly solid, softer than animal fats (coconut oil)
shorter carbon chains=softer fat
59
what happens when fat is oxidized?
spoiled
exposure to light & heat seeds rancidity
60
what protects against oxidation? which fats are more resistant?
hydrogenation (fully saturate)
saturated fats more resistant
polyunsaturated spoils earlier since double bonds are unstable
61
how to protect fat products from rancidity?
products sealed air tight non-metallic container, no light and in fridge (too $$ and inconvenient)
add antioxidants to compete for oxygen (BHA & BHT)
hydrogenation
62
why do saturated fats not melt at room temp? Why don't unsaturated?
no double bonds, fats stick together
bends @ double bonds
63
how does hydrogenation have food processing advantages?
protects against oxidation
alters texture by making liquid veg oils more solid
64
total hydrogenation _____ occurs
rarely
bonds that remain change from cis to trans
cis= hydrogen atom on same side of double bond
trans= hydrogen opposite sides of double bond
65
do trans fatty acids naturally occur?
how do they behave?
health concerns?
only a few, most are commercially made
behave like saturated fats (linoleic acid offers health benefits)
raises LDL, lowers HDLD, inflammation
66
what is now illegal in Canada as of 2010?
adding partially hydrogenated oils (PHO) to foods
67
why are synthetic antioxidants BHA and BHT added?
improve stability
68
digestion in the mouth
slow
lingual lipase (minor in adults, active in children due to milk)
hard fats melt with body temp
69
digestion of fats in stomach
floats on top, muscle contractions churn and propel stomach contents towards pyloric sphincter
solid to smaller particles
churning exposes small droplets to gastric lipase
70
pancreas' role in fat digestion
pancreatic lipase
major fat digesting enzyme break down fat into smaller for absorption
71
small intestine in absorption of fats
most of hydrolysis of triglycerides occurs here
removes triglycerides from fatty acid and glycerol
phospholipids have fatty acids removed by hydrolysis
sterols absorbed as is
72
bile is made how? How do AAs aid?
in liver from cholesterol, acid pairs with amino acids
improves emulsifing
73
most fat absorption is through where?
98% through intestinal villi
glycerol + small lipids are diffused into intestinal cells and absorbed into blood
monoglycerides + long chain fatty acids form micelles
74
what regulates production and release of chylomicrons into lymphatic system?
intestinal cells
enter bloodstream at thoracic duct
75
types of lipoproteins
chylomicron (largest, least dense, transports triglycerides to cells)
VLDL
LDL
HDL
76
more lipids, _____ density. more proteins _____ density
lipids = lower density
proteins = higher density
77
chylomicrons
largest, least dense
transports mostly triglycerides from small intestine into blood
cells remove triglycerides as they pass, making it smaller
protein receptors on membrane of liver sees them and removes (recycles)
78
VLDL
very low-density lipoproteins
made in liver, transports cholesterol and triglycerides
turns to LDL as cells remove triglycerides and cholesterol becomes most of its contents
79
LDL
low density lipoproteins
bad
made by liver, uses its cholesterol and phospholipids for energy, cell membranes, hormones
80
HDL
high density lipoproteins
good
made by liver to remove cholesterol and carry back to liver for recycling/ disposal
high dense = 50% protein
81
when is fat used for energy?
During certain times of aerobic exercise
Supplies 60% body’s energy needs during rest
Muscles fuel: provides energy (along with glycogen) to fuel muscular work
Emergency reserve:
main form stored energy
82
hormone sensitive lipase
energy deprivation leads to adipose cells dismantling stored triglycerides and releases glycerol and fatty acids into blood
- Energy-hungry cells throughout the body can then capture these compounds and process them through a series of chemical reactions to yield energy, carbon dioxide, and water
83
linoleic acid
omega 6
arachidonic acid AA via desaturation and elongation
conditionally essential
84
alpha linolenic acid
omega 3 (salmon, herring, mackerel, flaxseed)
makes EPA and DHA via desaturation and elongation (growth, vision, cognition)
85
fish with low or high mercury
High mercury: Swordfish, shark, king mackerel
Low mercury: cod, haddock, pollock, salmon, sole, tilapia, most shellfish
86
eicosanoids
made from AA and EPA
hormone like
AA/ omega 6= proinflammatory
EPA/ omega 3= anti inflammatory
87
how does aspirin work?
slowing synthesis of eicosanoids
88
omega 6 and 3 ratio
Suggested ratios range from 4:1 to 10:1
89
what happens to fat when you fast?
o Metabolism of body fat
o Some requirements of protein breakdown for CHO synthesis for brain/ nerve and RBC function
o Has to obtain energy from lean protein tissue since brain, nerves and red blood cells need glucose
- FA cannot be converted to glucose, only CHO and glycerol molecule of TG can
90
blood lipid profile is both non-modifiable and modifiable
non-modifiable (genetics)
modifiable (lifestyle)
91
atherogenic diet
high in SFA, Trans-FA, low in F & V, legumes, whole grains
92
%DV of saturated and trans fats & cholesterol
Saturated and trans fats grouped together for combined %DV
%DV for cholesterol is 300 mg regardless of energy intake
93
canadian standards of extra lean, lean, medium, regular
o Extra lean ground – 10% or less fat
o Lean ground – 17% or less
o Medium – 23% or less
o Regular – 30% or less
94
milk classification (% fat)
o Whole milk – 3.25%
o Reduced-fat or less-fat (2%)
o Low-fat (1%)
o Fat-free (skim)
