Essential Fatty Acids Flashcards
Are glycerophospholipids saturated?
Glycerophospholipids in membranes contain a saturated and an unsaturated fatty acid
What is contained in a glycerophospholipid?
In position 1: a saturated fatty acid mostly with 16 or 18 carbons
In position 2: An unsaturated fatty acid with 16, 18, 20 or 22 carbons containing one or more double bonds
What does MUFA mean?
Monounsaturated fatty acid
What does PUFA mean?
Polyunsaturated fatty acid
How does chain length and double bonds affect melting points?
The melting points of fatty acids increases with chain length and decreases with double bonds
How many single carbon to double carbon ratio in stearic acid? What is the melting point?
18:0 melting point- 70 degrees Celsius
What is the single carbon bind to double bond ratio of palmitic acid? What is the melting point?
16:0
Melting point- 63 degrees Celsius
What is the single carbon bind to double bond ratio of oleic acid? What is the melting point?
18:1
13 degrees Celsius
What is the single carbon bind to double bond ratio of palmitoleic acid ? What is the melting point?
16:1
1 degrees Celsius
What is the single carbon bind to double bond ratio of linoleic acid?what is the melting point?
18: 2
- 5 degrees Celsius
What is the single carbon bind to double bond ratio of a-linolenic acid? What is the me,ting point?
18: 3
- 11 degrees Celsius(comeback)
Explain the desaturation of fatty acids in humans
Desaturation of fatty acids is restricted in animals
-Humans can introduce a double bond between carbons 9 and 10. And form ๐ผ9
Ex. Oleic acid (18:1) is formed in humans from stearic acid (18:0)
Why can fatty acids be grouped into specific families?
Animals cannot form double bonds beyond ๐ผ9 toward the methyl end and that is why fatty acids can be grouped into specific families
What determines the fatty acid family?
The family is determined by counting backwards from the last carbon , independent of the length of the fatty acid until the first double bond is reached. This number will determine the w-family
a-linolenic is shown which. Is of the w-3 (n-3 ) family
How can animals form longer chain fatty acids?
Animals can introduce double bonds between ๐ผ9 and the carboxyl end and form longer fatty acids of the same family. But they cannot change the family
What can linoleic acid be used to form?
Linoleic acid 18:2, w6 can be used to form arachidonic acid 20:4, w6
Food rich in w6 fatty acids- nuts, avacado and corn
What can a-linolenic (w3) can be used to form?
a-linoleic acid (w3) can be used in humans to synthesize EPA and DHA which are found in biomembranes
Fish eat algae and form EPA and DHA
a-linoleic acid 18:3, w3 โ> EPA(eicosapentaenoic acid 20:5, w3)- - >. DHA( docosahexaenoic acid 22:6, w3
What is the purpose of TAG synthesis in hepatocytes?
Fatty acid synthesis and TAG synthesis for release into the blood inside of VLDL for fatty acid usage by other tissues
What is the purpose of TAG. degradation in adipocytes?
Fatty acids generated from TAG degradation in lipoproteins are taken up and are stored in form of TAGs. This benefits the whole body during fatty acid synthesis
Outline TAG synthesis in fat cells and hepatocytes
Glycolysis and glycerol (only liver) go to form glycerol 3-p
Glycerol 3-p And 2 fatty acyl CoAs form phosphatidic acid
Phosphatidic acid forms Pi and DAG
DAG uses 1 fatty acyl CoA to form TAG
What is the MAG pathway for TAG synthesis?
Only in intestinal mucousal cells
MAG formed by pancreatic lipase
Fatty acid CoA along with MAG form DAG
DAG along with fatty acyl CoA form TAG
What effect does high blood glucose and insulin have on TAG?
Increases TAG synthesis
How does epinephrine effect TAG?
Epinephrine โ> fight and flight (cAMP) lead to TAG degradation
How does epinephrine lead to TAG degradation in fat cells?
Epinephrine via cAMP/protein kinase pathway leads to phosphorylation of and activation of hormone sensitive lipase (HLP) in fat cells. This leads to TAG degradation and release of glycerol and free fatty acids into the blood