Lipids Flashcards
Lipids, Fats, and Oils
Lipids: compounds that include triglycerides (fats & oils), phospholipids, and sterols
Fats: lipids solid at room temp.
Oils: lipids liquid at room temp.
% of energy supplied by fat cells
60% at rest
Maintain structure and heath of cells (think cell-wall)
phospholipids and sterols
Fat’s role in the body
energy stores, muscle fuel, emergency reserve, padding, insulation, cell membranes, raw materials (converted to hormones, bile, and vitamin D as needed)
Triglyceride structure
glycerol backbone + 3 fatty acids
fatty acids vary in chain length and saturation
Chain Length of a fatty acid
number of carbons
saturation of a fatty acid
number of hydrogens
saturated fatty acid, saturated fats
every bond is filled with hydrogen
foods with low _________ are healthier
_are linked with cardiovascular disease and obesity
found mainly in animal products (less in some vegetable oils and hydrogenated fats)
also coconut and palm oil
unsaturated fatty acid
some hydrogens are missing
1 missing hydrogen= monounsaturated
2+ missing H’s= polyunsaturated
Plant fat is mainly
unsaturated fat
Which oils are healthiest?
olive and canola oil (plant oils) because they have less saturated fat
there is no difference in calorie or total fat content between oils, only types of fat contained in each oil (saturated or unsaturated)
Soft fat
healthier, but less stable form of fat
mainly unsaturated fatty acids
melts more easily (is less stable and used less in manufacturing)
ex: polyunsaturated (can turn rancid, susceptible to microbial growth)
Hard Fat
contains more saturated fat; is more stable, more resistant to oxidation,
cheaper, used more in processed foods
hydrogenation
forms trans fatty acids, makes the fats more saturated by adding hydrogens
hydrogens are all on the same side of the carbon chain (unique)
trans fats linked with cardiovascular disease and obesity
“partially hydrogenated oil”=trans fat
Essential Fatty Acids
need them to live, our bodies can’t make (obtained from food)
polyunsaturated, body readily stores them
health benefits: BP, clot formation, blood lipid concentration, immune/inflammatory response
types of essential fatty acids
Linoleic: omega-6
Linolenic: omega-3
Omega 6 fatty acid
linoleic essential fatty acid, found in seeds of plants, oils from seeds
vegetable oils, seeds, nuts, whole grain foods
lowers total cholesterol, and LDL cholesterol
omega 3 fatty acids
linolenic essential fatty acid,
role in metabolism, normal growth and development, primarily in fish oils
may protect against cancer
DHA & EPA ?
concerns: pregnant/lactating women & children, watch for mercury in fish, supplements not advised for these ppl
phospholipids
glycerol + 2 fatty acids +phosphate group…
ex: lecithins
roles: emulsifiers, cell membrane, not essential, made by liver
soluble in water and fat
cholesterol
is a sterol (sterol=a class of lipids) only in animal fat (meat, eggs, fish, poultry, dairy) NOT essential (can be made by body) made in liver can be made into bile or travel via blood to body cells less of a health risk in diet than saturated & trans fats, however raises body cholesterol, increases risk of heart disease
cutting ___ & ___ lowers LDL cholesterol
saturated fat and trans fat
Trans-fatty acids
raise LDL, lower HDL, produce inflammation
found in most margarins and all shortening
Monounsaturated Fat
healthy replacement for sat. and trans fat
ex: olive oil, contains phytochemicals
lower rates of heart disease in mediterranean where they use lots of olive oil
Fat Digestion
goal: dismantle triglycerides (bile breaks it down) monoglycerides, fatty acids, and glycerol
fats are hydrophobic where digestive enzymes are hydrophilic
Recommended fat intakes
total fat=20-35% of calories per day
saturated fat = <10% daily calories
about 1 tsp per meal
Fat supplies which vitamins
A, D, E, K
Equivalents of 5 grams of fat / 45 calories
oil: 1 tsp
mayo: 1.5 tse
cream cheese: 1 Tbsp.
sour cream: 1.5 Tbsp.
