Lipids Flashcards
What are some examples of lipids?
canola oil, distillers grains, corn oil, flax seeds, lard, megalac (rumen bypass).
What are lipids?
ether extracts in proximate analysis organic compounds contains C, H, O -insoluble in water -soluble in organic solvents Ex: acetone, methanol
Lipids in plant tissue
lipid content of most plants is relatively low except for oil seeds (canola, soybean, sunflower, and safflower oils)
lipids in animal tissue
relatively large amounts in animal tissue -adipose tissue -major form of energy storage amount is variable -diet, age, physiological state
Major function of fatty acids/lipids in the body
1) universal component of all cell membranes
- -lipid bilayer
2) long term energy storage
- -adipocytes
3) insulation
- -subcutaneous fat
4) component of enzyme systems
- -coenzymes Q
5) component of steroid hormones
- -estrogen, testosterone
6) fat soluble vitamin absorption, synthesis
- -vitamin A,D,E,K
Examples of simple lipids
1) fatty acids
2) acylglycerols
3) waxes
- sterol and nonsterol esters
examples of compound lipids
phospholipids, lipoproteins, glycolipids
single bond=
saturated
double bond=
unsaturated
What is fatty acid nomenclature based on?
1) number of carbons (chain size)
2) types of double bonds
3) positions of double bonds relative to the methyl (ω) or carboxyl end of the fatty acid
omega nomenclature
Fatty acids categorized into groups based on
where the first double bond is located
relative to the omega (ω)/methyl end
“n” system
delta nomenclature
Based on positions and type(s) of double
bond(s) relative to the delta (Δ)/carboxyl
end of the fatty acids
classification of fatty acids
Just as with nomenclature its based on:
a. Number of carbon atoms (chain length)
b. Presence/absence of double bonds between C atoms
c. Number of double bonds between C atoms
d. Configuration of double bonds
Melting point is the highest and greatest in what FA?
long chain fatty acid
saturated fatty acids (SFA)
only single carbon-carbon bonds
monounsaturated FA (MUFA)
1 double bond
polyunsaturated FA (PUFA)
more than 1 double bond
saturated fats are what at room temperature?
solid
monounsaturated fats are what at room temperature?
thick liquid or soft solid
polyunsaturated fats are what at room temperature?
liquid
does the cis or trans configuration have the lower chemical stability and melting point?
cis fatty acids
what are the two major types of PUFA?
2 major types of PUFA
❑ Omega-6 and omega-3 fatty acids
a. Linoleic acid (simplest omega-6 FA)
b. α-Linolenic acid (simplest omega-3 FA)
c. Linoleic & α-Linolenic acids = Essential fatty
acids
What are essential fatty acids?
Essential FA a. Linoleic acid or 18:2 Δ 9,12 (n-6) b. α-Linolenic acid or 18:3 Δ 9,12,15 (n-3) ❑ Not produced in the body because animals lack the necessary Δ 12 and Δ 15 desaturase enzymes
What are the functions of essential fatty acids?
Source of energy
b. Important structural components
c. Precursors to bioactive lipid mediators
❑ Eicosanoids = “signaling molecules”
❑ E.g., Prostaglandins; PGF2α = uterine contraction
symptoms of EFA Deficiency
Slow growth
b. Compromised immune function
c. Reproductive failure
d. Gastrointestinal problems
e. Irritated & flaky skin
What are the physiological functions of Omega-3 and Omega-6 FA?
Brain development
ii. Anti-carcinogenic
iii. Anti-atherosclerosis
What are aglycerols?
Glycerol bound to fatty acid(s) through an ester
linkage (esters of glycerol)
What are the functions of triglycerides?
Energy storage/production
ii. Insulation
iii. Protection of organs
iv. Provide essential fatty acids for body function
triglycerides as an energy reserve
Adipose tissue
❑ Made up of adipocytes
or “fat cells”
❑ Subcutaneous or visceral
B-oxidation of mobilized FA
Yields Acetyl-CoA:
i. Oxidized to CO2 in TCA cycle
❑ Also yields FADH2, NADH (oxidized to yield ATP)
ii.Used for ketone body synthesis (liver, muscle)
❑ Source of energy in brain, kidney, liver, skeletal
muscle
Yields FADH2, NADH:
❑ Co-enzymes involved in the mitochondrial electron
transport system
❑ Oxidized to yield ATP
What is a sterol?
steroid alcohol
What does a sterol do?
Lipids with distinctive multi-ring structure
b. Occur naturally in plants, animals
❑ Component of cell membranes
❑ Cholesterol = most familiar type of animal sterol
What is a sterol ester?
Chemical compound of a sterol molecule bonded to a fatty acid via ester linkage ❑ E.g., Cholesteryl ester ❑ Component of cell membranes ❑ In blood circulation
cholesterol sources
Foods of animal origin
b. De novo synthesis
❑ Primarily in the liver
❑ Influenced by genetics + diet
functions of phospholipids
Major components of cell membranes
❑ Amphipathic property
Play a key role in digestion, absorption,
transport of lipids
Found naturally in most foods
❑ E.g., Phosphatidylcholine or “Lecithin”
a. Stabilizer in food (e.g., mayonnaise, ice cream)
b. Found in the brain
❑ Important in neural development and function
What is an example of lipoprotein?
Chylomicrons ❑ Carriers of lipids in blood Hydrophilic surface monolayer ❑ Hydrophobic core
what are glycolipids?
Grasses rich in glycolipids
❑ Major source of lipids for animals consuming forages
b. Cerebrosides and gangliosides
❑ Subtypes of glycolipids
❑ Found predominantly in the brain, nerve tissue
