Lipids Flashcards
Is there any recommendation concerning cholesterol consumption, type of fat,etc.?
There is evidence to restrict cholesterol consumption to healthy people. However, there is one for people with cardiovascular diseases. CFG states that we should consume less saturated fat and eat more MUFAs and PUFAs
More omega 3 and less omega 6 ( the ratio should be 1:8, now 1:15)
Why low fat diet is not efficient?
Because our body can produce cholesterol on itself and also usually people balance lack of fats with more CHOs. As the result, consuming more calories, more obese
Name three types of lipids
1) triacylglycerol
2) phospholipids
2) sterols
How phospolipids and triacylglycerols related?
Phospholipids are the same as triacylglycerols, but one fatty acid substituted with phosphocholine
What property does phospholipids have?
Amphipathic compounds
Why plant products that claims no cholesterol on the package are not fair?
Cholesterol comes only from animal based products
Plants have phytocholesterol that we do not digest
What changes can be done to reduce fat in the diet?
To lower the milk fat percentage gradually
To trim the steak from fat, for example
In what products lecithin is found?
Eggs, mustard
What are functions of lipids in foods?
- 2 essential fatty acids
- concentrated energy
- carry fat soluble vitamins
- flavor,aroma,texture
- satiety
- emulsification
What are metabolic functions of fat in our diet?
- Adipose tissue is a concentrated energy store
- Cell membranes (phospholipid bilayer)
- Nerve impulse transmission
- Eicosanoid synthesis
What type of lipids is 99% of our diet?
Triacylglycerols
How the bond between glycerol and fatty acid is formed?
Ester bond with elimination of water( similar to glycemic bonds)
How can we use glycerol in our body (except triacylglycerols)?
To synthesize glucose
What is the reactive end and its polarity?
Carboxylic end. It is polar
What is the non-polar group in fatty acids?
Methyl end
Give the example of saturated fatty acids family and its short abbreviation
Stearic acid. 18:0
The example of MUFAs with the short name. Where can we find this fatty acid?
Oleic acid. 18:1.Omega-9 In the olive oil
What does Omega 9 mean in the naming of the fatty acid?
The position of the first double is located 9 carbons away from the methyl end.
Name 2 representatives of PUFAs class
Linolenic acid C 18:3 omega 3
Linoleic acid C 18:2 omega 6
Do we know the other positions of double bonds in linolenic acid?
Yes, as it is omega 3 and it has 3 double bonds, so the places are 3,6 and 9
For linoleic acid omega 6, so the other bond is at position 9
How do double bonds effect physical properties of lipids?
More double bonds, more liquid the fat at cooler temperatures
Why people hydrogenated fats?
For preservation
What happens to fats with double bonds on the sunlight?
Double bonds are very susceptible to oxidation( light, heat). As they are exposed to the light or heat, they turn to free radicals. These free radicals will cause other fatty acid to convert to free radicals as well. Eventually, can cause oxidative stress in the body and damage DNA, cause cancer
Hydrogenation is
Making double bonds into single bonds