FATS ch.6 (FINAL) Flashcards
(51 cards)
1
Q
what are the 3 general categories of dietary lipids?
A
- Triacylglycerols
- Phospholipids
- Sterols
2
Q
triacetylglycerols make up what percent of dietary fats?
A
- 95%
- store 3 fatty acids
3
Q
what do phospholipids do?
A
- they form lipid bilayer for cell membranes.
4
Q
what are sterols?
A
- Hormones, vitamin D, bile salts
- Cholesterol: important cell membrane component
5
Q
what are the 7 roles of lipids in nutrition?
A
- energy reserve.
- energy storage
- non-water soluble - Transport of fat-soluble nutrients
– vitamins A,D,E,K - Cellular structure
– plasma membrane - Signalling molecules
- second messengers - Protection of vital organs
- Insulation from cold
- Appetite control
– delays gastric emptying
6
Q
how many carbons are in the fallowing
1. Short-chain fatty acids (SCFAs):
2. Medium-chain fatty acids (MCFAs):
3. Long-chain fatty acids (LCFAs):
A
- 1-4 carbons
- 6-12 carbons
- 14-24 carbons
7
Q
what are saturated fats?
A
- The saturation of a fatty acid relates to its degree of hydrogenation
- there is a maximum number of hydrogen atoms avalible
- solid at room tempeture.
8
Q
what are unsaturated fats?
A
- these fats is when there is 1 or more carbon that is double bonded, that come from 2 unpaired electrons
- liquids/ oils
9
Q
what are the 2 categories of unsaturated fats?
A
- cis & trans
10
Q
what is the difference between cis and trans unsaturated fats?
A
CIS
- this is where the H atoms are on the same side and a “C” shape is formed.
- the carbon chain is on the same side of the double bond.
TRANS
- the carbon chain goes across from the double bond.
- the hydrocarbon chain is more linear.
11
Q
what are UFA, MUFA, PUFA?
A
UFA
- 1 or more double bonds between carbon atoms, each atom removes a 2 H atoms.
MUFA
- contains 1 double bond
PUFA
- contains 2 or more double bonds.
12
Q
what is hydrogenation?
A
- This is where oils are converted into saturated fatty acids.
- there are complete and incomplete.
13
Q
trans-fatty acids are harmful, what is increased that causes them to be harmful?
A
- promotion of systemic inflammation
- increasing LDL (bad cholesterol)
- decreasing HDL (good cholesterol)
14
Q
what are the 2 trans fatty acids that CAN be healthy?
A
- vaccenic acid
- omega-7 trans fatty acid
- possible anticarcinogen
- may lower cholesterol - conjugated linoleic acid
- 2 double bonds separated by one single atom
- may produce mild fat loss and lean mass gain.
- 28 variation.
15
Q
what are the 2 types of carbon nomenclature?
A
- first carbon next to -COOH is alpha-carbon (a)
- last carbon on chain is omega-carbon (w)
16
Q
what are the 2 essential fatty acids?
A
- omega-3 (alpha-linolenic acid)
- omega-6 (linoleic acid)
17
Q
what characteristics are associated with linoleic acid (omega-3)?
A
- high in N.A. diet
- require higher qualities than omega-3
- sunflower, corn, soybean oil.
- AI is 1.1 g/d (F) & 1.6 g/d (M)
EPA & DHA
18
Q
what characteristics are associated with alpha-linolenic acid (omega-6)?
A
- low in N.A. diet
- rich source is flax, chia, hemp.
- AI 12 g/d (F) & 17 g/d (M)
- GLA & AA
19
Q
what are conditionally essential fatty acids?
A
- synthesized in the human body from omega 3 & 6.
conversion efficiemcy is limited ~ 1-15%
20
Q
what are the 4 conditionally essential fatty acids?
A
- EPA
- DHA
- GLA
- AA
21
Q
what are the 2 conditionally EAA that come from linoleic acid (omega-6) and their characteristics?
A
- Gamma-linolenic acid (GLA)
- found in some plant seeds
- produce some anti and pro inflammatory compound
- can inhibit production of AA. - Arachidonic acid (AA)
- found at high levels in brain and muscle cells.
- plays a role in MSK growth, neural signalling, cell membranes.
- synthesization of pro inflammatory compound.
- meat, seafood, eggs.
22
Q
what are 2 CEFA in alpha-linolenic acid (omega-3) and their characteristics?
A
- Eicosapentaenoic acid (EPA)
- precursor to DHA
- reducing inflammation
- may reduce risk of CVD disease
- source of anti-inflammatory compounds. - Docosahexaenoic acid (DHA)
- reducing inflammation
- major component of cell membranes in the brain and retina.
23
Q
what is the role of essential fatty acids?
A
- modified in body to produce many signalling molecules
- inflammation, immunity, CNS signalling
- they are controlled by highly complex regulatory networks.
24
Q
Omega-3 fatty acids counter the inflammation effects of omega 6 fatty acids by what 3 mechanisms?
A
- Displacement
- competition for the same enzyme.
2.competitive inhibition
- blocking enzymes
3.counteraction
-downstream effectors that have opposing effects in the body.
25
what is the current AI recommendations for omega-6 & 3 ratio?
10:1 (omega-6: omega-3)
26
what is the current DRI for EPA/ DHA?
- no DRI specifically
- the typical range is 200-500 mg/d of EPA + DHA (total)
27
what are the 3 categories of dietary lipids?
- triacylglycerols
- phospholipids
- sterols
28
what are triacylycerols?
- fatty acids are basic subunits of most lipids.
- composed of glycerol (3 carbon polyol, 3 fatty acid tails, 16-18 carbons long.
- 98% dietary fat intake
- 90% of body lipids
29
how can triacylglycerols be broken down?
- triacylglycerol + H2O = FA + diacylglycerol
- diacylglyerol + H2O = FA + monoacylglycerol
- monoacylglyerol + H2O = FA + glycerol.
30
what are the 3 different lipases in triacyleglyceroz?
1. pancreatic lipases
- digestion of fat in gut.
2. lipoprotein lipase
- the bus that carries fat around in our blood. (lipoprotein is the bus)
3. Hormone-sensitive lipase
- responds to insulin/ glucogon
- insulin levels are turned on because they are low, and that is what creates the release.
31
what are phospholipids?
- have 2 hydrophobic fatty acid tails connected to water soluble polar he'd groups, that contain a phosphate.
- water soluble heads & fat soluble tails that allows lipid bilayer to form, which is important for cell membranes.
- important for brain function and health
32
what are sterols?
- these are made out of cholesterol, not fatty acids.
- 4 rings that are shared
33
what are the 4 molecule/hormones that are affected with sterols?
1. sex hormones
- androgens, estrogen
2. adrenal hormones
- glucicirticoids, mineralocorticoids
3. vitamin D
4. Bile salts
- fat digestion
- synthesized in gall bladder.
34
what pathway does cholesterol have?
first goes to
- progestagens
- which can either make mineral or glucocorticoids.
then goes to
- androgens after progestagens THEN to estrogen
35
fat digestion occurs where?
- small intestine.
36
short and medium chain triglycerides travel directly to where?
- liver.
37
what are chylomicrons?
- these are spheres of lipids and proteins that transport fats into the lymphatic system.
- they enter the blood after 3-6 hours.
38
what breakdown dietary fat?
- dietary fat molecule is secreted by bile salts, which then gets broken up by pancreatic lipase and then is used as a monoglyceride or a free fatty acid.
39
what is the density of lipoproteins?
- this depends on size.
BIG size = low density
SMALL size= high density
40
triacylglycerides and cholesterol are synthesized in the liver, and are packed into what?
- VLDL
- Very Low Density Lipoproteins.
- delivered to adipose and muscle tissue.
- if VLDL increase, so does the density.
41
what is the difference between chylomicrons and VLDL?
CHYLOMICRONS
- DIETARY SOURCE
VLDL
- SYNTHESIZED IN LIVER.
42
what is LDL?
-Low- Density Lipoproteins
- high cholesterol
- circulate in arteries and veins (periphery)
- associated with CVD
- "bad" cholesterol
43
what is HDL?
- "good" cholesterol
- high density of all lipoproteins
- removes cholesterol from peripheral tissues.
- decreases risk of CVD.
44
what is the source of VLDL, IDL, LDL, HDL?
1. liver
2. VLDL
3. Liver
4. Peripheral
45
what is the cargo (transport) of VLDL, IDL, LDL, HDL?
1. biosynthesized TAG
2.
3. cholesterol
4. cholesterol
46
what is the target location? of VLDL, IDL, LDL, HDL?
1. adipose
2.
3. peripheral
4. liver
47
what are factors affecting endogenous synthesis?
- high saturated fat intake.
high insulin levels.
48
1. high saturated fat intake does what to LDL and HDL?
2. synthetic trans fat intake does what to LDL and HDL?
3. replacing fat with MUFA does what to LDL and HDL?
1. increase LDL (bad) & HDL (good)
2. increase LDL (bad) & decrease HDL (bad)
3. decrease LDL (good) & increase HDL (good)
49
fat metabolism stimulated by what? and inhibited by what?
- epinephrine, norepinesphrine & insulin (pt2)
50
what does carnitine do?
- this gets fatty acid into the mitochondria.
51
1. what is ketosis?
2. what are ketone bodies, and what 3 things do they produce?
1. is an alternative pathway that is activated in low
carbohydrate conditions, when fatty acid oxidation is
increased.
2. formed from excess acetyl-CoA
- acetone
- acetoacetate
- beta-hydroxybutyrate
