Chapter 5 Flashcards
Identify the three types of lipids.
Triglycerides
Phospholipids
Sterols
Identify the three types of lipids.
Triglycerides
Phospholipids
Sterols
What is the structure of a triglyceride? How are they classified?
Three fatty acid molecules
Fatty acids are long chains of carbon atoms surrounded by hydrogen atoms
One glycerol molecule
Glycerol is a 3-carbon alcohol that is the backbone of a triglyceride
What is the most common food-based lipid?
Triglycerides
Sources of Monounsaturated fat?
Olive oil, Canola oil, and cashew nuts
Sources of Polyunsaturated fatty acids?
Cotton seed, canola, corn, and safflower oil
Where are sat fats found in foods? Why should they be limited in the diet and how much should we eat?
Saturated Fat less than 7-10% of our total energy.
Found in animal products,
Can raise cholesterol, cardiovascular disease, cancer,
What are trans fats? Where are these found in foods?
found in processed foods, and in fried foods.
How does absorption of fat differ based on the chain length of the fatty
acid?
Short- and medium-chain fatty acids are absorbed more quickly since they are not arranged into chylomicrons.
Triglycerides in the chylomicrons must be disassembled by lipoprotein lipase (LPL) before they can enter body cells.
After entering body cells, triglycerides can be:
Used immediately for energy Used to make lipid-containing compounds Stored in muscle or adipose tissue for later use
Understand the function of the following in digestion of fat: gallbladder,
liver, pancreas, bile, small intestine, Pancreatic enzymes.
Fats are not digested and absorbed easily because they are insoluble in water.
Little digestion of fats occurs in the watery environments of the mouth or stomach.
As fat enters the small intestine:
Bile is secreted from the gallbladder into the small intestine
Bile is produced by the liver and stored in the gallbladder
Bile disperses fat into smaller fat droplets (like soap)
Pancreatic enzymes break fat into 2 separate fatty acids and a monoglyceride
Micelles trap the free fatty acids and monoglycerides and transport them to the mucosal cells for absorption.
Fatty acids are reformulated back into triglycerides and packaged into lipoproteins for transport to the lymphatic system and blood.
What is emulsification? What is secreted into the GI tract for this to occur?
Bile
Briefly describe each of the reasons why we need fats in our diets.
Energy
Fat is very energy dense, containing 9 kcal per gram. 30-70% of the energy used during rest comes from fat. Fat is used for energy during exercise, especially after glycogen is depleted. Fat is also used as a way to store extra energy in the body for later use.
Fat is essential to many body functions
Part of cell membrane structure Facilitates nerve cell transmissions Protection of internal organs Insulation to retain body heat
What is the AMDR for total fat?
The Acceptable Macronutrient Distribution Range (AMDR) for total fat: 20-35% of calories should be from fat
Athletes and highly active people may need more energy from carbohydrates and can reduce their fat intake to 20-25% of total calories.
The AMDR for essential fatty acids:
5-10% of calories from linoleic acid (11 to 17 grams per day based on gender) 0.6-1.2% of calories from alpha-linolenic acid (1.1 to 1.6 grams per day based on gender)
What are the dietary recommendations for cholesterol, sat, and trans fats?
Cholesterol-less than 300 mg
Saturated Fat-Less than 7-10% of total energy
Trans Fat- 0
What is the structure of a triglyceride? How are they classified?
Three fatty acid molecules
Fatty acids are long chains of carbon atoms surrounded by hydrogen atoms
One glycerol molecule
Glycerol is a 3-carbon alcohol that is the backbone of a triglyceride
