test 2 - omega 3

Question 1

True or False: Alpha-linolenic acid (ALA) is an essential fatty acid which plants synthesize and therfore EPA and DHA are conditionally essential Fatty Acids.

Answer 1

TRUE

Question 2

What foods contain the most widely available dietary sources of EPA and DHA? (SMASHT)

Answer 2

Salmon
Mackerel
Anchovies
Sardines
Herring
Tuna

Question 3

Where in the body are the highest concentrations of DHA?

Answer 3

Retina and Cerebral Cortex

Question 4

What enzymes are used to get alpha-linolenic acid to Docosapentaenoic acid?

Answer 4

Alpha Linolenic acid: delta 6-desaturase, elongase, delta 5-desaturase, –> EPA
EPA: elongase, elongase, delta 6-desaturase, Beta oxidation –> DHA

Question 5

The enzyme Elongase uses what substrate in order to lengthen the Fatty acid Chain by 2 carbons

Answer 5

Malonyl-CoA

Question 6

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

Answer 6

delta 6-desaturase

Question 7

True or False: one explanation for the poor conversion of ALA to DHA is that ALA is the most rapidly oxidized unsaturated Fatty Acid and so a large portion of ingested ALA is beta-oxidized to acetyl-CoA

Answer 7

TRUE

Question 8

True or False: Alcohol inhibits delta 6-desaturase but not delta 5-desaturase which therefore reduces EPA and DHA conversions

Answer 8

False: Alcohol inhibits delta 6-desaturase and delta 5-desaturase which therefore reduces EPA and DHA conversions

Question 9

DHA supplementation raises EPA levels though a process known as _________-___________

Answer 9

Retro-Conversion

Question 10

Explain why EPA and DHA are more susceptible to lipid oxidation than other fatty acids.

Answer 10

EPA and DHA are more susceptible to lipid oxidation because they simply have more double bonds than other fatty acids and double bonds are more susceptible to oxidation because they contain pie bonds which make the electrons easy to grab and pull away, especially by free radicals who are looking for an extra electron to achieve stability.

Question 11

Omega-3 Fatty Acids in fish oil are thought to be beneficial in treating or helping what diseases?

Answer 11

Hypertriglyceridemia
Heart disease
Insulin resistance
Cancer
Neurodegenerative diseases such as:
-Depression & Anxiety
Inflammatory diseases including:
-Rheumatoid Arthritis
-Osteoporosis
-Inflammatory bowel disease
-asthma

Question 12

What poly unsaturated Fatty Acid helps inhibit the release of arachidonic acid from phospholipids by competitively inhibiting phospholipase A2

Answer 12

Eicosapentaenoic acid (EPA)

Question 13

What novel anti-inflammatory and inflammation resolving mediators do EPA and DHA produce?

Answer 13

Resolvins

Question 14

True or False: Nuclear Factor kappa B (NFkB) and Peroxisome proliferator activated receptor gamma (PPARy) are two transcription factors that play a role in inflammation

Answer 14

TRUE

Question 15

True or False: Both EPA and DHA up-regulate the activation of NFkB

Answer 15

False: Both EPA and DHA down-regulate the activation of NFkB

Question 16

True or False: Both EPA and DHA will bind to and activate PPARy which activates NFkB and hence limits inflammation.

Answer 16

False: Both EPA and DHA will bind to and activate PPARy which inhibits the activation of NFkB and hence limiting NFkB’s inflammatory actions.

Question 17

PGE2 is a modulator of ___________ activity and at moderate levels of PGE2, supports bone formation, but at high concentrations it promotes bone resorption

Answer 17

Osteoblast

Question 18

PGE2 is a potent stimulator of bone resorption at ______ concentrations

Answer 18

high

Question 19

PGE2 directly activates the ___________ receptor of progenitor osteoclasts which results in their activation

Answer 19

RANKL

Question 20

True or False :EPA is better than DHA for reducing triglycerides

Answer 20

False: DHA is better than EPA for reducing triglycerides

Question 21

True or False: DHA will increase Low-Density Lipoprotein concentration more than EPA

Answer 21

TRUE

Question 22

EPA and DHA are activators of __________ which down-regulate the activity of NFkB, which plays a key role in the regulation of gene expression in inflammatory responses by cells.

Answer 22

Peroxisome proliferator activated receptor gamma (PPARy)

Question 23

EPA and DHA decrease triacylglycerol concentrations by regulating 2 nuclear transcription factors: what are those Factors and what do they do?

Answer 23

1) Activation of PPAR-alpha, which increases hepatic beta-oxidation via the activation of Lipoprotein lipase leading to the reduction of the fatty acid substrates for triacylglycerol synthesis
2) Decreased activation of sterol regulatory element-binding protein-1c (SREBP-1) decreases lipogenesis via reduced production of Fatty acid synthase.

Question 24

True or False: Omega-3’s may prevent calcium overload by increasing the activity of the L-type Calcium channels.

Answer 24

False: Omega-3’s may prevent calcium overload by decreasing the activity of the L-type Calcium channels.

Question 25

Does it matter whether you supplement with EPA or DHA?

Answer 25

no, use both!

Question 26

True or False: Omega-3’s may inhibit carcinogenesis of breast cancer though inhibition of NFkB

Answer 26

TRUE

Question 27

True or False: PPAR-y is a transcription factor that serves as a tumor suppressor by activation the gene for syndecan-1 (SDC-1), a proteoglycan which inhibits the phosphorylation and therefore activation of other transcription factors involved in cell division.

Answer 27

TRUE

Question 28

The optimal intake level for Omega-3’s is approximatley __ g/day

Answer 28

3g/day

Question 29

EPA inhibits the release of ____________ acid from phospholipids by competitively inhibiting an enzyme called ____________________

Answer 29

Arachidonic Acid, Phospholipase A2