Biochemistry Omega-3 Fatty Acids

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

3g/day

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

False: DHA is better than EPA for reducing triglycerides

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

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

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

Osteoblast

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.

Peroxisome proliferator activated receptor gamma (PPARy)

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

True

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

True

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.

True

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

True

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

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.

PGE2 is a potent stimulator of bone resorption at ______ concentrations

High

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

True

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.

True

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

Malonyl-CoA

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

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

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

Arachidonic Acid, Phospholipase A2

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

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.

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

Eicosapentaenoic acid (EPA)

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

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

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

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

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

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

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

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

Does it matter whether you supplement with EPA or DHA?

No, use both

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

RANKL

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

Resolvins

Where in the body are the highest concentrations of DHA?

Retina and Cerebral Cortex

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

Retro-Conversion

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

Salmon Mackerel Anchovies Sardines Herring Tuna

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

delta 6-desaturase