HS 20 - Weir
LIPIDS
What is a Lipid?
 Lipids are a diverse group of organic compounds that are _________________ in water.
 Lipids are present everywhere! They are the reason that you are unable to wash your
face with water alone; you need some type of soap to break the insoluble lipids before
you can wash them away.
 Lipids can serve as key components in _____________________________, act as
cushions for delicate organs of the body, serve as carriers of vitamins, and
_______________________________and other important chemicals.
 Lipids are __________________________________
 This means that they resist dissolving in water, but can dissolve in other non-polar
molecules
 Most lipids are composed of two main structural components
1) Glycerol = ____________________________________________________________
2) Fatty acid chain = ______________________________________________________
____________________________________________________________________
Fatty acids are the ________________________of the fat in our bodies and in the food we eat.
During digestion, the body ______________________________ into fatty acids, which can then
be absorbed into the blood.
Fatty acid molecules are usually joined together in groups of three, forming a molecule called
a triglyceride.
Fatty acids have many important functions in the body, including________________________.
If glucose (a type of sugar) isn't available for energy, the body uses
_____________________________________________________________________________.
Lipids include molecules like:





HS 20 - Weir
We will study 4 types of Lipids:
1) Triglycerides
2) Waxes
3) Phospholipids
4) Steroids
1) Triglycerides
 Formed by _____________and ____________________________
 ________ of the fats we eat are Triglycerides
 Tri = 3 fatty acid chains, Glyceride = glycerol backbone
 Triglycerides that are ____________ at room temperature (ex. Butter) are called ______
o Can also be called _______________________________
Saturated Fats:
 Contain __________ single bonds between carbons
These can be found in:
 ________________________________________________________________________
__________________________________________________________________________
* Called saturated because they are saturated with more Hydrogen
* ______________________________ are usually saturated fats.
 Triglycerides that are ____________at room temperature (ex. Olive oil) are called _____
o Can also be called _____________________________
HS 20 - Weir
Unsaturated Fats:
 Contain ______________________________________
These can be found in:
 ________________________________________________________________________
___________________________________________________________________________
**Since there is a double bond there is _________ room for hydrogen = unsaturated with
hydrogen
Saturated
Unsaturated
Structure
State at Room Temperature
Melting Point
Cholesterol
Recommended Consumption
Trans Fat:
 An unhealthy substance, also known as trans fatty acid, made through the chemical
process of hydrogenation of oils.
 Hydrogenation solidifies liquid oils and increases the ____________________ and the
flavor stability of oils and foods that contain them. Trans fat is found in vegetable
shortenings and in some margarines, crackers, cookies, snack foods and other food
 Trans fats are also found in abundance in "french fries." To make vegetable oils suitable
for deep frying, the oils are subjected to hydrogenation, which creates trans fats. Among
the hazards of fast food, "fries" are prime in purveying trans fats.
HS 20 - Weir
2)Waxes
 Are long chains of fatty acids that are tightly packed and linked to alcohols or carbon
rings
 They have a _______________________________
 They _____________ water
 In the human body, waxy secretions are used for ____________________, and
lubrication of the skin and hair
3)Phospholipids
 Composed of:
◦
A glycerol backbone
◦
______________________________________________
◦
A phosphate group with choline as the “head”
 The ________ of the phospholipid has a negative and positive charge. This makes it
_______________.
 Polar molecules can dissolve in water (since water is also polar)
 We call this _______________________.
 The tails of the phospholipid are non-polar. This means
they_______________ like water. They will not dissolve in water.
 We call this ________________________.
 This gives phospholipids a very unique structure.
 They have one end that is hydrophilic and one end that is hydrophobic
 Because of this unique characteristic. Phopholipids arrange themselves in a specific way
called the ________________________________________
 This bilayer makes up the membranes of all the cells in the ____________________.
HS 20 - Weir
4) Steroids
Steroids are hydrophobic and insoluble in water
Steroids are naturally produced in the body
 Composed of: ________________________________________
 Examples of Steroids:______________________________________________________
Fats and Diet
 Fats are a required part of our diet although problems arise when you consume too
much fat.
 Doctors recommend no more than _______ of total energy intake should be in the form
of fats.
 ____________________________ has been associated with diets high in saturated fats.
 _______________________________ and obesity have also been linked to breast
cancer, colon cancer and prostate cancer.
 Obesity has also been linked to high blood pressure and _________________________.
What is Cholesterol?
 Cholesterol is a type of ________ found in your blood.
 Your ____________ makes cholesterol for your body.
 You also can get cholesterol from the______________________________. Meat, fish,
eggs, butter, cheese, and whole or low-fat milk all have cholesterol in them
HS 20 - Weir
TEXTBOOK QUESTIONS
In the textbook read page 64 and answer the following questions:
1) In what ways do plant and animal fats differ? (This questions is from page 62)
2) Heart disease is the number one killer of North Americans. What can cause it?
3) List a few items that may contribute to reducing blood cholesterol levels?
4) What are the 2 types of cholesterol “packaging”? Which one is good and which one is
bad?
5) Define plaque.
6) Evidence shows that what 2 things in a diet reduce cholesterol?