Fats and Lipids. Fats or Lipids Used by the body for: stored energy, insulation, and cell membranes. In cell membranes fats called phospholipids help.

Fats and LipidsFats and Lipids

Fats or LipidsFats or Lipids Used by the body for: stored energy, insulation, and cell Used by the body for: stored energy, insulation, and cell

membranes. In cell membranes fats called phospholipids membranes. In cell membranes fats called phospholipids help regulate the water and ions going in and out of the help regulate the water and ions going in and out of the cell membrane. Other uses of fats by the body include cell membrane. Other uses of fats by the body include the production of cholesterol, some hormones, skin oils, the production of cholesterol, some hormones, skin oils, and ear wax.and ear wax.

Fats are broken down into fatty acids by enzymes, bile Fats are broken down into fatty acids by enzymes, bile salts, and acid in the small intestine before being salts, and acid in the small intestine before being absorbed into the blood.absorbed into the blood.

Fats have twice as many calories per gram than a Fats have twice as many calories per gram than a carbohydrate.carbohydrate.

Fats are more difficult to digest than carbos, and so are Fats are more difficult to digest than carbos, and so are often storedoften stored

The largest category or type of fat is called a triglyceride.The largest category or type of fat is called a triglyceride.

Fats or lipids cont.Fats or lipids cont. Two categories of triglycerides are:Two categories of triglycerides are:

• Saturated fatsSaturated fats Come from animalsCome from animals Solid at room temperatureSolid at room temperature Contain no double bonds between the carbons. They Contain no double bonds between the carbons. They

have the maximum amount of hydrogen in their have the maximum amount of hydrogen in their structure possible, thus, saturated with hydrogen.structure possible, thus, saturated with hydrogen.

Noted for producing LDL cholesterol. This type of Noted for producing LDL cholesterol. This type of cholesterol contributes to heart disease in conc.cholesterol contributes to heart disease in conc.

• Unsaturated FatsUnsaturated Fats Come from plantsCome from plants Oils at room temperature due to having a very low Oils at room temperature due to having a very low

melting point.melting point. Contain at least one double bond between the carbons.Contain at least one double bond between the carbons. Considered to be healthier due to the body’s Considered to be healthier due to the body’s

predisposition for converting them into HDL predisposition for converting them into HDL cholesterol.HDL prevents heart disease. (However, cholesterol.HDL prevents heart disease. (However, one’s cholesterol level is greatly influenced by one’s cholesterol level is greatly influenced by genetics)genetics)

Fats or lipids cont.Fats or lipids cont. Two reactions of fatty acidsTwo reactions of fatty acids

• Saponification or making soap.Saponification or making soap. Uses a fat (lard or oil) and NaOHUses a fat (lard or oil) and NaOH Heating the fat with NaOH causes the triglyceride to separate into a Heating the fat with NaOH causes the triglyceride to separate into a

glycerol molecule and 3 fatty acids. The fatty acids are molecules glycerol molecule and 3 fatty acids. The fatty acids are molecules with a polar head and nonpolar tail which means that they can with a polar head and nonpolar tail which means that they can intersperse among both polar and nonpolar substances. (Zum p. intersperse among both polar and nonpolar substances. (Zum p. 1111)1111)

• Addition reaction with IodineAddition reaction with Iodine Used to determine the number of double bonds in a fatty acid.Used to determine the number of double bonds in a fatty acid. The IThe I22 which is purple, is attracted to the double bonds in a fatty which is purple, is attracted to the double bonds in a fatty

acid. The Iacid. The I22 breaks the double bond and attaches to the fat. This breaks the double bond and attaches to the fat. This reaction is easy to do and see in the lab because one mole of Ireaction is easy to do and see in the lab because one mole of I22 breaks one bond in one mole of fat, and there is a distinct color breaks one bond in one mole of fat, and there is a distinct color change from purple to colorless when the Ichange from purple to colorless when the I22 breaks the double bond. breaks the double bond.

II22 is attracted to the valence e is attracted to the valence e-- in the double bonds. in the double bonds.

Two examples of fatty acidsTwo examples of fatty acids

Triglycerides continuedTriglycerides continued Triglycerides consist of 3 fatty acids and Triglycerides consist of 3 fatty acids and

one glycerol molecule.one glycerol molecule. If one of the fatty acids is saturated than If one of the fatty acids is saturated than

the triglyceride is considered to be a the triglyceride is considered to be a saturated fat.saturated fat.

Our bodies can convert triglycerides into Our bodies can convert triglycerides into different types or categories of fats which different types or categories of fats which are used for other purposes.are used for other purposes.

Fats or lipids cont.Fats or lipids cont.

3 fatty acids + one glycerol combine 3 fatty acids + one glycerol combine to maketo make

One triglycerideOne triglyceride

Storage of fatsStorage of fats Fats are stored in specialized tissue called Fats are stored in specialized tissue called

adipose.adipose. The cells in adipose can expand and The cells in adipose can expand and

contract like a balloon to store the fats.contract like a balloon to store the fats. Adipose tissue is located between muscles Adipose tissue is located between muscles

and skin, and between internal organs.and skin, and between internal organs. Some people call adipose tissue cellulite.Some people call adipose tissue cellulite.

Adipose tissueAdipose tissue

Diagram of adipose tissueDiagram of adipose tissue

Food pyramid Food pyramid