Chapter 8- Lipids (Oct 27 lec)

Question 1

lipids are \_\_\_\_(organic/ inorganic) compounds
Lipids are:
- relatively \_\_\_\_ in water 
- relatively \_\_\_ in organic solvents 
- have a high content of \_\_\_\_\_

Answer 1

organic

insoluble in water

soluble

hydrocarbons

Question 2

the simplest fatty acid is:

Answer 2

acetic acid

*describe/ draw out general fatty acid structure

Question 3

Fatty acids have 2 ends. Describe each

Answer 3

Methyl end: non poplar, hydrophobic

Carboxyl end: polar, hydrophilic

Question 4

in most animal and plant fats, the chains are ___ with a(n) ___ number of carbons

Answer 4

straight

even

Question 5

the longer a fatty acid chain is, the more ___ it is. Why?

Answer 5

hydrophobic

- b/c short chains are easier to digest- they’re more hydrophilic

Question 6

“short” fatty acid chains contain __ carbons are are the product of ______ ____ of fibre
short chains are also ___ (gas)

Answer 6

<6C

microbial fermentation
volatile

Question 7

“medium” chain fatty acids have __ to ___ carbons and are a product of ___

Answer 7

6 to 12

digestion

Question 8

___ chain triglycerides are easy to absorb (water soluble)

Answer 8

medium

Question 9

“long” chain fatty acids have __ Carbons and are in most ___ fats/ oils

Answer 9

> 14

feed fats and oils

Question 10

“very long” chain fatty acids have ___ carbons and are found in the fats/ oils of ___ ___

Answer 10

> 22

specialized feeds

Question 11

Are individual fatty acids usually found in free form in feeds? Explain

Answer 11

No, usually part if more complex molecules (triglycerides, phospholipids, etc)

Question 12

Describe saturated fatty acids

Answer 12

• no double bonds
• straight chain
• tend to be solid at room temp (fats)

Question 13

describe unsaturated fatty acids

Answer 13

• have at least 1 double bond
• each cis double bond introduces a kink into the molecule
• tend to be liquid at room temp (oils)

Question 14

monounsaturated=

polyunsaturated=

Answer 14

one double bond (1 kink)

more than 1 double bond (more than 1 kink)

Question 15

Double bonds usually appear __ carbons apart

Answer 15

3

Question 16

describe the difference between cis vs trans unsaturated fatty acids

Answer 16

cis= double bond, has the kink

trans= retains relatively linear/ straight configuration despite the double bond(s). Behave like saturated fatty acids

Question 17

standard (delta) notation for naming fatty acids:

Answer 17

carbons numbered beginning at the acid (carboxyl or COOH) end
- also position of double bonds

Question 18

omega notation for naming fatty acids

Answer 18

C numbered beginning at the methyl (CH3) end

- also position of double bonds