Lipids (midterm) Flashcards
What is the monomer of lipids?
TGs
FAs are rarely free in nature, they are usually linked to other molecules by their….
hydrophilic carboxylic acid group
FAs primarily exist as….
unbranched hydrocarbon chains
How are FAs classified?
1) number of carbons
2) number of double bonds
3) position of the last double bond in the chain
What are SCFAs found in?
-breast milk
-coconut oil
-dietary soluble fiber
SCFAs have how many carbons?
less than 6 carbons
ex:
-acetate has 2 C
-propionate has 3C
-butyate has 4 C
MCFAs have how many carbons?
6-12 carbons
ex: lauric acid has 12 C
T/F: MCFAs need bile for absorption
false
MCFAs is found in what oil?
coconut (also has SCFAs in there)
What are the 2 health benefits of MCFAs?
-facilitates weight loss
-can treat neurodegenerative diseases
Most FAs in nature are- SCFAs, MCFAs, or LCFAs?
LCFAs
How many carbons are there in LCFAs?
12+ carbons
ex: palmitate has 16 carbons
What are the 2 subclasses for LCFAs?
MUFAs (omega 9) and PUFAs (omega 3 and 6)
What are the 3 health benefits of SCFAs?
-good for baby
-keeps colon cells healthy
-keeps gut flora healthy
What does a saturated FA structure look like?
no double bonds
Are saturated FAs usually short or long?
long
Are saturated FAs usually solid or liquid at room temp?
SOLID (some are liquid like palm oil and coconut oil, but butter, lard, and animal fat are solid)
Which FAs have a higher melting and smoke point?
saturated FAs
What food has saturated FAs?
-butter, lard, animal fat
-palm oil
-coconut oil
Saturated fats in general are associated with increased serum _____________ levels and higher _______
cholesterol, LDLs
What does an unsaturated FA structure look like?
with double bond (if carbons are on same side = cis double bond, if opposite sides then its a trans double bond)
Are MUFAs liquid or solid at room temp?
test q
liquid
Are MUFAs liquid or solid in the refrigerator?
test q
solid
oleate has what omega classification?
omega 9
Oleate is extracted from which oil?
olive oil
Which FA has lower smoke points and is not good for high heat cooking methods such as frying?
MUFAs
What are some examples of MUFA food sources?
test q
-olive oil
-canola oil
-safflower oil
-peanut oil
-most nuts in general
-avocado
If you burn oil and it smokes then it will make carcinogens and release it into your food. How do you prevent this?
add oil and food at the same time so that the food will absorb the oil rather than heating the oil first and getting overheated
Which FA is liquid at room temp and refrigerator?
PUFA
Which omega classifications are PUFAs?
omega 3 and 6 FAs
What are the 2 important PUFAs that are essential?
1) linoleic acid (18:2, omega 6)
2) alpha linolenic acid (18:3, omega 3)
How many carbons and double bonds are there in linoleic acid?
18:2
What is the omega classification for linoleic acid?
omega 6
How many carbons and double bonds are there for alpha linolenic acid?
18:3
What is the omega classification for linolenic acid?
omega 3
Which omega class should we try to eat the most?
omega 3
What foods have omega 3 FAs?
-salmon
-tuna
-herring
-mackerel
-cod liver oil
-flaxseeds
-walnuts
-wheat germ oil
Eicosapentanoic acid (EPA) 20:5 and docosahexaenoic acid (DHA) 22:6 are related. Both of these are metabolized to form….
omega 3 eicosanoids
What is the recommended intake of fish per week?
2x a week
Human brains and CNS cell membranes require ___________ for optimal function
EPA/DHA
Increased omega 3 FA in the diet is associated with:
-decreased incidence of cardiovascular disease
-decreased plasma TG levels
-decreased inflammatory disorders
-decreased symptoms of RA
-decreased severity of asthma in children
-improved lung function in people with cystic fibrosis
-decreased severity of symptoms in psychiatric disorders like schizophrenia and depression
-decreased incidence of colon, breast, prostate, and lung cancers
-decreases symptoms of ADHD in children
Omega 6 FA is found in what foods?
veggie oil
How much veggie oil (omega 6 FA) should you consume a day?
1 tablespoon
Arachidonic acid 20:4 can be made from omega 6 linoleic acid. Arachidonic acid is considered conditionally essential. It is metabolized to form….
omega 6 eicosanoids like prostaglandins, thromboxanes, and leukotrienes
Eicosanoids are made when released by what enzyme?
phospholipase A2
Eicosanoids mediate what?
-pain sensation
-immune function
-vasodilation/constriction
-inflammation
-blood clotting
-muscle contraction
-short term memory
-intestinal motility
Aspirin is an irreversible inhibitor of?
cyclooxygenase (COX 1 and 2, aka prostaglandin and thromboxane)
What is the function of omega 6 eicosanoids like arachidonic acid?
-increase blood clotting
-increase inflammatory responses
What is the function of omega 3 eicosanoids like DHA and EPA?
-decrease blood clotting
-reduce risk of heart attack
T/F: almost all cells in the body are capable of producing eicosanoids
true
T/F: all eicosanoids have the same effect on different tissues
false
What percentage of Americans are deficient in essential FAs?
60%
What are the signs and symptoms of essential FA deficiency?
-flakey, itchy, dry skin
-dry hair
-infections
-impaired vision
-reduced learning
-hyperactivity in kids
-memory problems
-allergies
-inflammatory diseases
-depression
-violence
-heart disease
-arthritis
-soft nails
-polydipsia (excessive thirst)
Which oil is the highest in saturated fat?
test q
coconut oil
Which oil is the highest in MUFAs (omega 9 oleic acid)?
test q
safflower oil and olive oil
Which oil is the highest in alpha linolenic acid (omega 3, PUFA)?
flaxseed oil
Which oil is the highest in linoleic acid (omega 6, PUFA)?
sunflower oil
What is hydrogenation of FAs?
-process is used to solidify an oil to increase the melting temp
-addition of H to carbon double bonds
-formation of trans FA, which increases shelf life
What foods are high in trans FAs?
-hydrogenated fats
-deep fried food
-high fat baked goods
-non-diary creamers
-salty snacks
-commercial cakes, cookies, and other baked goods
Excessive trans fat intake raises _______ and lower _______
LDL, HDL
Excessive trans fat intake increases risk for what disease?
heart disease
How much cholesterol should we consume a day?
200-300 mg