Chapter 4- Fats Flashcards
Are lipids soluble in water?
No
What are the 3 main categories of lipids?
triglycerides, sterols, phospholipids
What makes up a triglyceride?
one glycerol molecule and 3 fatty acids
What are the two essential fatty acids?
Linoleic acid and alpha linoleic acid
What are the two types of sterols?
Cholesterol and plant sterols
What are saturated fatty acids?
They are full of hydrogens and can stack together making them solid at room temperature, structural component of cell membranes and can be made in the body
What are unsaturated fatty acids?
Due to the kinks at double bonds, they are not full of hydrogens and do not stack neatly
What are the two types of unsaturated fats?
Monounsaturated and polyunsaturated
What is a monounsaturated fatty acid?
It has one double bond
What is a polyunsaturated fatty acid?
It contains more than one double bond
What is the difference between cis configuration and trans configuration?
Cis configuration has the hydrogen on the same side of the double bond and trans configuration has hydrogen on the opposite side of the double bond
Where is cholesterol found?
Only in animal-based foods (eggs, meat, poultry, cheese)
Why is there a difference in cholesterol absorption?
20-80 absorption from food, differences occur because of genetics
What are plant sterols?
They are sterols similar in structure to cholesterol and therefore interfere with the body’s absorption of cholesterol
Who are plant sterols good for?
Individuals with high cholesterol
What is a negative of plant sterols?
Decreases the bioavailability to vitamin A
What are phospholipids?
They are a lipid composed of glycerol, fatty acids, and a phosphate group, naturally found in some foods and added to processed food as emulsifiers (mixes/smooths)
What are phospholipids important for?
Absorption, transport, and storage of lipids as well as aiding and digestion and absorption of dietary fat
What are unique traits of monounsaturated fatty acids?
Synthesized by the body, and the US diet contains more monounsaturated fats than other types, oleic acid being the most abundant
Benefits of switching to monounsaturated fats from saturated fats?
Lower total LDL (bad) cholesterol and increase HDL cholesterol, lower triglyceride compared to carbs
What are the most common polyunsaturated fatty acids?
Omega-6 (linoleic acid) and Omega-3 (alpha linolenic acid)
What is Omega-6 important for?
cell function and gene expression, and membrane structure and cell signaling
What are the 3 primary omega-3 fatty acids consumed in the diet?
ALA, EPA, DHA
What does ALA do?
We need it to make the other two, side effect of not having enough is scaly dry skin
What does EPA do?
Protective against heart attacks and strokes
What does DHA do?
Important for brain development/function
What do trans fats do?
increase LDL cholesterol, reduce HDL cholesterol, reduce LDL particle size, which are all risk factors for coronary heart disease
What are the dietary recommendations for saturated fat?
Less than 10 percent of calories
What are the dietary recommendations for fat?
20-35% of total calories, but no specific number
Digestion and metabolism of fats starts where?
In the mouth with the enzyme lingual lipase
What are absorbed into the fatty acids after being broken down by enzymes with bile?
Free fatty acids
After absorption, free fatty acids are packaged into what?
chylomicrons
If fat and cholesterol are held by fiber what happens?
It exits the body through feces
What can be stored as body fat?
All energy-yielding macronutrients
What leads to increases in stored fat?
overfeeding fat not carbohydrates or proteins
Can the brain and nervous system use fat straight from fatty acids?
No, they have to convert it to ketones
What exercise uses fats?
low-intensity exercise that is not calorically demanding
When should excess dietary fat be avoided?
pre workout or competition as fat slows the rate of digestion
