UNIT 6 Flashcards
The Lipids
Lipids
A family of organic compounds soluble in organic solvents but not in water. Lipids include triglycerides (fats and oils), phospholipids, and sterols.
Triglycerides
Make up roughly 95% of lipids in foods and the human body, and is one of the three primary dietary lipids.
Defined as: The chief form of fat in foods and the human body. Is made up of 3 units of fatty acids and one unit of glycerol.
Also referred to as: “triacylglycerols”
phospholipids
Another of the three dietary lipids. They have the ability to attract water-soluble as well as fat soulbe substances; they can facilitate the passage of fats in and out of cells through the membranes .
These are present in all cell membranes.
Lecithin (LESS-ih-thin)
a phospholipid manufactured by the liver and also found in many foods.
It is a major constituent of cell membranes.
Sterols
A lipid with a characteristic hydrocarbon ring structure; all sterols are derived from cholesterol.
What are the three main classes of lipids?
triglycerides
phospholipids
Sterols
What are three uses of fat in the body?
Energy Storage
Muscle Fuel
Emergency Reserve
What are three uses of fats in food?
Nutrients as fatty acids
Sensory Appeal
Energy (fat contains concentrated energy in calories)
What are essential fatty acids
Fatty acids that the body needs but cannot make in amounts sufficient to meet physiological needs.
General Question: What is the amount of calories provided by 1g of carbohydrates, lipids, and proteins respectively?
1g Carbs= 4 Cal
1g Lipid= 9 cal
1g protein= 4 cal
Satiety (sat-EYE-uh-tee)
The feeling of fullness or satisfaction that people experience after a meal
How does fat contribute to the feeling of Satiety
The fat of swallowed food triggers a series of physiological events that slow down the emptying of the stomach and promote this feeling.
Fatty Acids
organic acid composed of carbon chains of various lengths. Each fatty acid has an acid end and hydrogens attached to all the carbon atoms of the chain
glycerol
An organic compound, three carbons long, of interest here because it serves as the backbone for triglycerides.
Saturated Fatty Acids (SAFA)
a fatty acid carrying the maximum possible number of hydrogen atoms (having no points of unsaturation)
What are the three types of fatty acids
Saturated
monounsaturated
polyunsaturated
point of unsaturation
a site in a molecule where the bonding is such that additional hydrogen atoms can easily be attached
Unsaturated fatty acid
a fatty acid that lacks some hydrogen atoms and has one or more points of unsaturation. An unsaturated fat is a triglyceride that contains one or more unsaturated fatty acids.
monounsaturated fatty acid (MUFA)
a fatty acid containing one point of unsaturation
polyunsaturated fatty acid (PUFA)
a fatty acid with two or more points of unsaturation
Saturated fats
triglycerides in which most of the fatty acids are saturated
trans-fat
fats that contain unusual fatty acids; trans fatty acids are largely formed during processing.
monounsaturated fats
triglycerides in which most of the fatty acids have one point of unsaturation
Emulsifier
a substance that mixes both fat and water and permanently disperses the fat in the water, forming an emulsion