Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Nutritional Biochem 2 > Final Exam (Omega-3 Fatty Acids) > Flashcards

Final Exam (Omega-3 Fatty Acids) Flashcards

1
Q

Alpha-Linolenic (ALA)…

A

18:3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Eicosapentaenoic (EPA)…

A

20:5

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Docosahexaenoic (DHA)…

A

22:6

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What living thing makes ALA?

A

Plants

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

*The most widely available sources of EPA and DHA are cold water fish, what are these fish?

A 
SMASH-T
Salmon
Mackerel
Anchovies
Sardines
Herring
Tuna
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

*DHA concentrations are highest where? EPA concentrations are highest where?

A
  • DHA - Retina/Cerebral cortex

- EPA - TRICK QUESTION, LOW EVERYWHERE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

The conversion of ALA to EPA/DHA occurs where? What is unique about this conversion?

A
  • Occurs in the SER

- The FINAL step (B-ox) occurs in the peroxisome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q
  • Delta-5 desaturase… AKA…

* Delta-6 desaturase… AKA…

A
  • FADS1 (Fatty acid desaturase)

- FADS2 (fatty acid desaturase)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

*ALA –> D6-desaturase –> elongase –> D5 desaturase =

A

EPA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

*EPA –> Elongase –> Elongase –> D6 desaturase –> B-oxidation =

A

DHA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

The level of EPA/DHA in where is an indicator of Omega-3 FA intake?

A

RBC membrane!

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

*What is the rate limiting step in ALA conversion to EPA and DHA?

A

D6-Desaturase (very inefficient)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

*Since conversion of ALA to DHA is so poor, what would one explanation for this be?

A
  • ALA is the most rapidly oxidized unsaturated FA, a large portion of ingested ALA is then B-oxidized to Acetyl-CoA
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

*What will inhibit D6 and D5 desaturase and reduce EPA and DHA concentrations in the body?

A
  • ALCOHOL
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are the two elongase enzymes that help convert EPA –> DHA?

A
  • Elovl2

- Elovl5

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

*What is the most rapidly oxidized unsaturated FA, and less of this gets converted to DHA…

A
  • ALA
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Which FA competes with ALA for D6-desaturase?

A

Linoleic Acid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Does DHA or EPA supplementation raise EPA levels?

A

DHA raises EPA levels through Retro-conversion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

*What confounds efforts to establish cause and effect relationships between dietary EPA and DHA?

A

Retro-conversion

DHA –> EPA thru Beta-ox

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

T/F: Increased seafood consumption outweighs the risk of mercury? (SMASHT)

A

TRUE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

*If someone takes >3g/day of Omega-3 FA, what can result?

A
  • Moderate GI upset
  • Likely fishy aftertaste in the mouth
  • Moderate level of worsening Glycemia
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Is there a regional variation in mercury concentration depending where you are? Which body of water has the most ppm of mercury, and which has the least…

A
  • YES
  • Gulf of mexico (1.45ppm)
  • North Atlantic (0.05ppm)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

This is a neurotoxin and can impair normal neurological development in a fetus or child….

A

Methylmercury

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What are the 3 reasons fish oil supplements do not contain as high of levels of mercury than a serving of fish?

A
  1. smaller fish -low in mercury
  2. mercury binds to protein (fish meat, not oil)
  3. mercury may be removed in the making of oil (distilled)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

*Which type of salmon have lower concentration s of mercury than wild ocean-caught salmon?

A
  • Farm-raised
26
Q

*Farm-raised salmon have high levels of what 3 things? Who should avoid this?

A
  • Dioxins
  • Polychlorinated biphenyls (PCB)
  • Chlordane
  • young children, pregnant/nursing women
27
Q

*High enough concentrations of what is considered a carcinogen?

A
  • PCB (polychlorinated biphenyls (PCB)
28
Q

*What 2 things are more susceptible to lipid oxidation than other fatty acids? and why?

A
  • EPA/DHA

- Due to them having more double bonds (5, 6)

29
Q

*Why are polyunsaturated fatty acids easily oxidized?

A
  • Because they have an electron which can be easily scavenged
  • Free radicals easily grab this electron due to the ease of the sp2 hybridized p-p (pi) bond that can separate…
30
Q

*Why do many companies put Vitamin E in their Fish oil supplements?

A
  • Vit E is a preservative that keeps the fish oil from going rancid
  • If there is no vitamin E or other preservative in the capsule the oil can go bad, and you are putting OXIDIZED fish oil in your body = BAD!
31
Q

Omega-3 FA in fish oil are thought to be beneficial in treating…

A

Hypertriglyceridemia, Heart disease, insulin resistance, cancer, neurodegenerative diseases (depression, anxiety), RA, Osteoporosis, IBD, asthma

32
Q

*EPA/DHA both will do what to NFkB (nuclear factor kappa B)?

A
  • Down-regulate
33
Q

*EPA/DHA will bind to activate what substance that will then inhibit the activation of NFkB –> limits inflammatory actions…

A
  • PPARy (PPAR-gamma)
34
Q

*(COX-PGH2) –> _______

A
  • Prostacyclin (vasodilation, inhibit platelet aggregation)
35
Q

*(COX-PGH2) –> _______

A
  • Thromboxane (vasoconstriction, promote platelet aggregation)
36
Q

*Arachidonic acid –> Cyclooxygenase –> ______

A
  • PGE2 = vasodilation, increase vascular permeability
37
Q

*Arachidonic acid –> Lipoxygenase –> ______

A
  • Leukotrienes (B4) = vasoconstriction, bronchospasm (all leukotrines are involved with ASTHMA)
38
Q

*Arachadonic undergoes hydrolysis at what position?

A
  • Sn-2 position
39
Q

*Healthy ratios of Omega-6: Omega-3 should be what?

A

1:1, 4:1

40
Q

EPA or DHA will compete and replace what at which position of the glycerophospholopids?

A
  • Arachidonic acid
  • Sn-2 position
  • Therefore, this will decrease arachadonic acid and decrease all inflammatory eicosanoid production!
41
Q
  • EPA inhibits release of arachidonic acid via competitive inhibition of what?
  • EPA reduces eicosanoid production by competitively inhibiting what?
A
  • Phospholipase A2

- COX and 5-LOX

42
Q

EPA/DHA produce novel anti-inflammatory and inflammation resolving mediators called…

A
  • Resolvins
43
Q

*What 3 resolvins are produced through COX-2 and 5-LOX enzymes?

A
  • Resolvin E1 (RvE1)
  • Resolvin D1 (RvD1)
  • Neuroprotectin D1 (NPD1)
44
Q

What is the primary action of resolvins?

A
  • Shut off ongoing inflammatory process to limit tissue damage
45
Q

*Resolvin E1, D1, Neuroprotectin E1 all serve to inhibit what two things?

A
  • IL-1

- TNF

46
Q

*Resolvin E1, D1, Neuroprotectin E1 all inhibit neutrophil infiltration at the sites of inflammation by reducing what two things?

A
  • E-selectin

- ICAM-1

47
Q

*NFkB turns on what?

A
  • Pro-inflammatory genes!
  • EPA and DHA downregulate this!
  • EPA/DHA activate PPARy –> inhibits NFkB
48
Q

*PGE2 at high concentrations activates what?

A
  • RANKL receptors of preogenitor osteoclasts which then activates bone resorption. At mild levels it supports bone formation.
  • A high Omega6:3 ratio means there is an excess of arachidonic acid which will produce more PGE2
49
Q

*Omega-3 vs Cancer…

A

Anti-inflammatory, pro-apoptotic, antiproliferative, antiangiogenic, estrogen antagonist, activator of PPARy (tumor supressor gene)

50
Q

*Omega-3 vs CVD…

A
  • Decrease trigs, increase blood viscosity, vasodilator, decrease inflammation, increase mitochondrial function, decrease BP, decrease platelet adhesion and organ damage, antiarrhythmic, vasoprotective
  • Anti-thrombotic, Anti-atherogenic, anti-arrythmic, vasoprotective
51
Q

*Is DHA or EPA better for reducing triglycerides?

A
  • DHA

- This will increase LDL’s more though, as opposed to EPA

52
Q

*>3g/day of fish oil will increase what?

A
  • Bleeding

- Can increase the risk of Hemorrhagic stroke

53
Q

EPA and DHA are precursors to what?

A
  • Resolvins E1 and D1

- Neuroprotectin E1

54
Q

*Omega-3’s may prevent overload of this nutrient? How is this done?

A
  • Calcium
  • Omega-3’s do this by inhibiting the activity of L-type Ca channels during period of stress and increase the activity of cardiac Ca/Mg ATPase active transports that move calcium back into the SR
  • Basically, this mechanism works to prevent excess Ca from accumulating in the cardiac cell’s cytoplasm and therefore may prevent the development of arrhythmias
55
Q

*Activation of PPARy will activate what to inhibit TAG synthesis and increase FFA Beta-ox…

A
  • Adiponectine
56
Q

*Activation of PPAR-alpha will increase hepatic beta-ox via what mechanism to reduce triglyceride substrates and decrease lipogenesis (decrease FA synthesis)

A
  • Lipoprotein lipase
57
Q

*Omega-3’s promote insulin sensitivity which in turn does what?

A
  • Protects the body against insulin resistance
58
Q

What are some markers of oxidative stress?

A
  • MDA
  • oxLDL
  • 8-oxoguanine
  • Reduced Vit C
  • Reduced Vit E
  • Increased glutathione peroxidase and catalase
59
Q

Lipid membrane peroxidation is involved in 2 different diseases, what are they?

A
  • Atherosclerosis

- DNA damage

60
Q

*What are the 3 conditions where Omega-3 supplements are most effective?

A
  • Hypertriglyceridemia
  • Hypertension
  • Prevention of Secondary CVD

Nutritional Biochem 2 (6 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions