Chapter 3 Fats Flashcards
How many kcal/g do we get from fats?
9
Where do fats rank among carbohydrates and proteins as far as providing energy is concerned?
second to carbohydrates
In what body tissue are our fat cells stored?
adipose tissue
Are animal fats usually solid or liquid?
solid
Are plant based fats usually solid or liquid?
liquid
Are fats hydrophobic or hydrophilic?
hydrophobic
What are the four major categories of fats?
Fatty Acids
Glycerides
Steroids (sterols)
Lipoproteins
Which class of fat is our body fat?
glycerides (triglycerides)
What are the two classes of fatty acids?
Saturated
Unsaturated
What is the functional group on the end of a fatty acid (hydrocarbon) chain called?
carboxyl group
How is the carboxyl group represented chemically?
C double bond to O
and single bond to OH
Do saturated fatty acids have single bonds or double bonds in the carbon chain?
only single
Are saturated fatty acids liquid or solid at room temperature
solid
Are saturated fats found more in animal products or plant products?
animal
Is this a mono- or poly- unsaturated fat?
How do you know?
What is the acid name (name and omega name)
monounsaturated
because it has only one double bond in the carbon chain
oleic acid (omega-9)
Is this a mono- or poly- unsaturated fat?
How do you know?
What is the acid name (name and omega name)
polyunsaturated fat
it has two or more double bonds in the carbon chain
linoleic acid (omega-6)
Is this a mono- or poly- unsaturated fat?
How do you know?
What is the acid name (name and omega name)
polyunsaturated
it has two or more double bonds in the carbon chain
alpha-linolenic acid (omega-3)
What is the name for the far left end of the fatty acid chain?
Name both names
methyl or omega
How do you determine if a unsaturated fatty acid is an omega 3, 6, or 9
count the number of carbons from the methyl/omega end before hitting the first carbon bond
Are unsaturated fatty acids completely full of hydrogen?
No
Are unsaturated fatty acids solid or liquid at room temperature?
liquid
What are food sources of monounsaturated fatty acids?
oils (olive, peanut, canola)
nuts
avocados
What are food sources of polyunsaturated fats?
vegetables oils (safflower, sunflower, corn)
Explain what an essential fatty acid is
a fat we must consume in the diet. we cannot make it in the body.
What are two sources of essential fatty acids?
Alpha-linolenic acid (omega-3)
Linoleic acid (omega-6)
What type of body functions are Alpha-Linolenic Acid (Omega-3) and Linoleic (Omega-6) important for?
tissue strength
cholesterol metabolism
cardiovascular health
What are the dietary reference intakes of linoleic (omega-6) fatty acids for men and women?
17 g/day for men
12 g/day for women
what are the dietary reference intakes for alpha-linolenic (omega-3) fatty acids for men and women?
1.6 g/day for men
1.1 g/day for women
What are the two isomers of fatty acids with double bonds called?
cis and trans
Where are the hydrogen atoms located on the double bond in a cis fatty acid?
On the same side
Where are the hydrogen atoms located on the carbon double bond of a trans fatty acid?
opposite sides
Is this a cis fatty acid or a trans fatty acid?
cis
is this a cis fatty acid or a trans fatty acid
ignore red circle to the side
trans
Which configuration are most naturally occurring fatty acids found (cis or trans)?
cis
How are most trans-fatty acids formed?
Vegetable oils are partially hydrogenated (hydrogen is added)
hyrogen is forced on the double bonds, but the configuration is trans not cis
Why does industry create trans fatty acids?
they want the oil to become a solid
What are the majority of dietary fats made of?
triglycerides
what is the structure of triglycerides?
three separate fatty acid chains attached to an alcohol backbone
does the glycerol need to be dehydrated to attach to the fatty acid chain?
yes
what is this structure?
triglyceride
what type of fats is stored in our body fats?
triglycerides
How are phospholipids related to triglycerides?
They are a derivative of triglycerides. The third fatty acid is replaced by a phosphate group.
Why is a phospholipid partially hydrophobic and partially hydrophilic?
fatty acid tail (lipid): hydrophobic
phosphate (hydrophilic)
which type of fat is this a picture of?
phospholipid
What type of fat makes up our cell membrane?
phospholipid
what subgroup of fats are sterols?
steroids
What two steroids (sterols) found the in the body?
phyosterols
zoosterols
What produces phyosterols?
plants
what produces zoosterols?
animals
What is an example of a zoosterol humans create?
cholesterol
What zoosterol is found in the cell membrane and what is its function?
cholesterol
helps make cell memrane more rigid and less fluid
how many rings do steroids have in their chemical structure?
four
do different steroids have different functional groups or the same functional groups coming off of them?
different
What are examples of steroids in the body?
estrogen
testosterone
glucocorticoids
cholesterol
Does most of our cholesterol come from dietary cholesterol or from what the body makes?
What the body makes
What are some sources of dietary cholesterol?
eggs and organ meat
What is endogenous cholesterol?
the cholesterol our liver produces
Is cholesterol a nutrient of concern for overconsumption?
no
What is a complex lipid?
lipoproteins
what is the job of lipoproteins?
transport fat and cholesterol in the blood
what are two transporters of fat and cholesterol?
low density lipoprotein (LDL)
high density lipoprotein (HDL)
Where does LDL carry the fat and cholesterol to?
the cells
Where does HDL carry the cholesterol to?
away from the cells to the liver for metabolism
does dietary fiber assist with the absorption of fat-soluble vitamins?
yes
does fat provide flavor to our foods?
yes
do fats send a signal to the brain of being satisfied?
yes
How do fats help with flavor and satisfaction?
fats digest slower
fuller texture
slower to empty from the stomach
What two things does adipose tissue do for us?
protects organs
regulates temperature
what three things are the primary sources of animal saturated fat and cholesterol in our diet?
meat
dairy
egg yolks
What are our sources of mono and polyunsaturated plant fats in the diet?
vegetable oils such as olive, peanuts, safflower
What are two sources of saturated plant fats in the diet?
coconut and palm oil
What is the path for the digestion of fats in the body?
Mouth–>stomach–>small intestine
In the small intestine
bile from gallbladder–>enzymes from pancreas–>enzymes from small intestine–>absorption where dietary fat is carried as chylomicrons through lymph and blood
What happens in the mouth in the digestion of fats?
mechanically and chemically
mechanical breakdown of food
chemical digestion with lingual lipase
What happens in the stomach with the digestion of fats?
mechanically and chemically
`
mechanically, peristalsis mixes fat with water and acid
chemically, gastric lipase breaks down fat more
What happens in the small intestine with the digestion of fats?
mechanically and chemically?
bile from gallbladder enters small intestine from common bile duct and emulsifies fat (take a big glob and breaks it up into smaller droplets) to give it more surface area for pancreatic lipase to break down small droplets of fat.
triglycerides are emulsified by pancreatic lipase and turn back into fatty acids and glycerol and possibly monoglycerides.
monoglycerides, fatty acids, and bile form micelles that are absorbed in the bloodstream
micelles go into mucosal cell and triglycerides are rebuilt. the re-formed triglycerides combine with cholesterol, phospholipds, and proteins to form chylomicrons, which are absorbed into lymphatic system
what is a monoglyceride?
a glycerol w/ one fatty acid attached
What happens in the large intestine with digestion of fats?
might be some additional digestion but mostly excreted in feces
what are the government health guidlines for fats?
low fat, low saturated fat, low cholesterol
fat content 20%-35% of total kcal
less than 10% kcal saturated fat
dietary cholesteral limited to 300 mg/day
