N: LIPIDS: triglycerides, phospholipids, sterols Flashcards
what are phospholipids?
make up cell membrane
they have a glycerol head with a fatty acid tail
glycerol and fatty acid attached by OH group ( H - HO)
what are triglycerides?
main storage fats - (most related to diet)
what are sterols?
cholesterols
what is the energy component for each macro nutrient:
fat= 9g alco= 7g carb= 4g protein= 4g
how do you differentiate between fatty acids?
number of hydrogens attached to carbon chains
saturated fatty acid:
all C atoms saturated with H atoms
unsaturdated fatty acids:
lacks 2 or more H atoms
at least 1 C=C double bond-> point of unsaturdation
monounsaturdated:
lacks 2 H atoms
1 double bond
what is omega 6?
essential fatty acid that must be provided by food
linoleic acid -> arachidonic acid
cell signalling molecule involved in the inflammatory process
what is omega 3?
linolenic acid -> EPA and DHA
important for eyes and brain
examples of saturated fats
animal fats
palm/coconut oil
example of monounsaturdated fats
olive
canola
peanut oil
example of polyunsaturated fat:
veg oils eg. flaxseed sunflower soy bean walnut
what is a benefit of omega 3?
reduces the risk of heart attack and stroke
where do you get linoleic acid from?
veg oils - safflower oils
where do you get arachidonic acid from?
meats, eggs, poultry
where do you get linolenic acid from?
flaxseed
where do you get EPA & DHA from?
fish
what are trans-fatty acids?
artificial TFAs -> linked to heart disease
how are trans-fatty acids produced?
produced via hydrogenation process
describe what makes a trans-fatty acid:
Hydrogens on double bonds are on opposite sides(trans rather than cis)
cis - hydrogens on the same side
describe structure of sterols(cholesterol):
multiple ringed structure
where is cholesterol found?
only found in animal foods
eg. meat, eggs, fish
cholesterol is the starting material for:
bile salts
sex hormones
adrenal hormones
vitamin D
how much cholesterol is produced per day and where?
liver produces 800-1500mg of cholesterol daily
what does too much saturated fat and cholesterol do?
clogs artery - heart disease, cardiovascular disease
no such thing as “good” and “bad” cholesterol in the diet
describe VLDL:
lipoprotein shell containing fat and cholesterol
deposits fat in adipose tissue
after fat is deposited becomes LDL
describe LDL:
lipoprotein shell containing cholesterol
- “bad” sticks to blood vessel walls, form clots
describe HDL:
protective effect
- liver produces “empty” shells, go into blood stream & pick up LDL
outline role of saturated fat, trans fats and cholesterol in the development of heart disease:
cholesterol blocks artery wall
saturated fat INCREASES LDL -> increasing risk of clot
trans fat[the worstttt] increases LDL & decreases HDL -> not only increasing risk of clot, but also decreasing body’s ability to remove LDL from wall
how to lower LDL and raises HDL?
- weight control
- replace saturated fat with mono&poly unsaturated fat eg. avo, canola
- physical activity
- genes may make you more prone -> influences uptake, synthesis, transport and degradation of lipoproteins
what are the “good” fats to consume? why?
mono: decrease LDL, increase HDL
poly: decrease LDL, decrease HDL
examples of mono and poly unsaturated foods:
mono: olive, canola oil, avo
poly: veg oil, margarines, nuts and seeds
what is the chemical composition of a triglyceride?
3 fatty acid chains attached to a glycerol molecule
what is meant by the term poly unsaturated fatty acid?
fatty acid containing more than 1 carbon-carbon double bond
- less hydrogen saturation
what is meant by the term essential fatty acid?
a fatty acid necessary for health that must be obtained from the diet, as body cannot produce it itself
name 2 types of essential fatty acid and list 2 good food sources:
omega 3: EPA & DHA= fish linolenic= flaxseed oil omega 6: linoleic= safflower oil arachodonic= meats
2 acids in omega 3:
EPA & DHA
linolenic
2 acids in omega 6?
arachodonic acid
linoleic acid
what is meant by the term trans-fatty acid?
unsaturated fatty acid with 1 or more C=C
it is artificially made via hydrogenation process
with hydrogens in trans figuration (H on opposite sides)
name one artificial process that can produce trans-fatty acids:
hydrogenation of polyunsaturated fats
eg. make margarine
list 3 foods that might contain trans-fatty acids:
deep fried foods, cake, chips, pastries
high intake of trans fatty acids is linked to which disease?
CardioVascular Disease
increases LDL
decreases HDL
