Lipids

Question 1

Fatty Acids :

Answer 1

Fatty acids are carbon chains connected to a carboxin group. Fatty acids are the building block of lipids
macromolecules. In the chain, the first carbon is called alpha (α) and the last one called Omega (Ѡ).

Question 2

Types of lengths to the carbon chain:

Answer 2

1. Short chain - fatty acids with aliphatic tails of five or fewer carbons
2. Medium chain - fatty acids with aliphatic tails of 6 to 12 carbons
3. Long chain - fatty acids with aliphatic tails of 13 to 21 carbons.

Question 3

Saturation and examples:

Answer 3

Saturation of fatty acids is a consequence of double bonds between the carbons. If the molecule has only
single bonds, it is saturated, while the presence of double bond makes the molecule unsaturated

—->Saturated:
16C –Palmitic Acid
18C – Stearic Acid
20C – Arachidic Acid

---->Unsaturated:
16C:1∆9 – Palmitoleic Acid 
18C:1∆9 – Oleic Acid 
18C:2∆9,12 – Linoleic Acid 
18C:3∆9,12,15 – Linolenic Acid  
20C:4∆5,8,11,15 – Arachidonic Acid

Question 4

Essential fatty acids:

Answer 4

"essential" means molecules that the body needs, but cannot produce on its own. 
 3 unsaturated fatty acids: 
- Linoleic acid 
- Linolenic acid 
- Arachidonic acid

Question 5

Omega:

Answer 5

Is referring to the last carbon alone. The distance between that carbon, to the first double bonded
carbon, is determined whether the fatty acid is essential or not. Omega 6 and below are essential since the
body cannot introduce a double bond so close to the end of the chain.

Question 6

𝑻𝑨𝑮 – Tri Acyl Glycerol

Answer 6

A triglyceride (TG, triacylglycerol, TAG, or triacylglyceride) is an ester derived from glycerol and three fatty acids (from tri- and glyceride). Triglycerides are the main constituents of body fat in humans and other animals, as well as vegetable fat. They are also present in the blood to enable the bidirectional transference of adipose fat and blood glucose from the liver and are a major component of human skin oils.

Question 7

𝑻𝑨𝑮 – Tri Acyl Glycerol Structure location and function:

Answer 7

—->Structure – a T.A.G is made of glycerol and connect with 3 fatty acids by an ester bond.

—->Location- the triacylglycerols are stored by adipocytes around the body.

—->Function – the triacylglycerols has 3 main functions:
@ Energy storage
@ Thermal isolation and
@ Cushioning of internal organ.

Question 8

Phospholipids:

Answer 8

Structure - amphipathic molecule with a polar head and nonpolar tail. The molecule is made of glycerol
connected with two fatty acids to form the tail and a phosphate group from the head. The phosphate group
is additionally connected to one of three other molecules:
* Serin
* Chlolin
* Ethanol amiod
Functions:
1. Cell membrane and other internal structure of the self. 2. Forming surfactant in the lungs.
3. Helping lipid digestion.
4. Storage of essential fatty acids.

*Surfactants are compounds that lower the surface tension (or interfacial tension) between
two liquids or between a liquid and a solid. Surfactants may act as detergents, wetting agents, emulsifiers,
foaming agents, and dispersants.
**Phospholipids can be made from both saturated and unsaturated fatty acids.

Question 9

Cholesterol:

Answer 9

Structure – amphipathic molecule, made of four sterol rings and connected with proteins. There are several
kinds of cholesterols molecules, and the two most notable are:
1. 𝐻𝐷𝐿 – high-density lipoprotein. The “good” cholesterol is mobilizing fat from body tissue into the
liver.
2. 𝐿𝐷𝐿 – low-density lipoprotein. The “bad” cholesterol is doing the opposite.
Functions:
1. Participate in the formation of the cell membrane.
2. Precursor of steroid hormones( Like, Oestrogen Testosterone, Aldosterone.)
3. Assisting in lipid digestion (bile).