Q. All the following are carbons containing fatty acids, except
Solution:
Lipids are non-polar biomolecules soluble in organic solvents such as chloroform and generally insoluble in water. Lipids include fats, phospholipids and steroids. Fats have fatty acids which could be simple or conjugated (compound).
The fatty acid contains a carboxyl group (-COOH) at one end that is attached to an R group. The R group may be simply a methyl (-CH3) or a higher number of -CH2 groups (up to 19). For example, including carboxyl carbon, palmitic acid has 16, and arachidonic acid has 20 carbon atoms. These carbons form long unbranched hydrocarbon chains. These simple fatty acids differ from one another in having (i) hydrocarbon chain length, typically from 14 to 20 carbon-long (maybe 4 to 36 carbons long) and (ii) presence or absence of a double bond.
Saturated fatty acids have no double bond in the hydrocarbon chain. For example, palmitic acid; and represented as 16:0, where 16 shows the number of carbon atoms while 0 shows no double bond.
Unsaturated fatty acids have one or more double bond (-C=C-). For example; palmitoleic acid (16:1), where 1 means it has one double bond. Some more examples are given in the table below.
Unsaturated
The fatty acid contains a carboxyl group (-COOH) at one end that is attached to an R group. The R group may be simply a methyl (-CH3) or a higher number of -CH2 groups (up to 19). For example, including carboxyl carbon, palmitic acid has 16, and arachidonic acid has 20 carbon atoms. These carbons form long unbranched hydrocarbon chains. These simple fatty acids differ from one another in having (i) hydrocarbon chain length, typically from 14 to 20 carbon-long (maybe 4 to 36 carbons long) and (ii) presence or absence of a double bond.
Saturated fatty acids have no double bond in the hydrocarbon chain. For example, palmitic acid; and represented as 16:0, where 16 shows the number of carbon atoms while 0 shows no double bond.
Unsaturated fatty acids have one or more double bond (-C=C-). For example; palmitoleic acid (16:1), where 1 means it has one double bond. Some more examples are given in the table below.