Lipids

Question 1

a family of substances found in living organisms that are insoluble in water but soluble in nonpolar solvents and solvents of low polarity

Answer 1

Lipids

Question 2

Lipids play three major roles in human biochemistry:

Answer 2

1. they store energy within fat cells.
2. they are parts of membranes that separate compartments of aqueous solutions from each other, and
3. they serve as chemical messengers.

Question 3

Lipids can be classified into four groups:

Answer 3

1. simple lipids such as fats and waxes;
2. complex lipids;
3. steroids; and
4. prostaglandins, thromboxanes, and leukotnenes.

Question 4

consist of a hydrocarbon chain with a carboxylic acid at one end

Answer 4

Fatty acid

Question 5

2-4 carbon atoms

Answer 5

short chain FA

Question 6

6-10 carbon atoms.

Answer 6

medium chain FA

Question 7

12 - 26 carbon atoms

Answer 7

long chain FA

Question 8

are two examples of essential fatty acid

Answer 8

linoleic and linolenic

Question 9

Is a ubiquitous component of plant lipids and of all the seed oils of commercial importance.

Answer 9

Linoleic acid

Question 10

is thought to decrease the risk of heart disease by helping to maintain noral heart thythin and pumping it might also redure blood clots:

Answer 10

Linolenic acids

Question 11

Polyunsaturated fatty acids occur in higher concentration in lipids associated with structural elements of tissues.

Answer 11

Structural elements of tissues

Question 12

Lipids of gonads also contain a high concentration of polyunsaturated fatty acids, which suggests importance of these compounds in reproductive function.

Answer 12

Structural element of gonads

Question 13

Prostaglandins are synthesised from Arachidonic acid by cyclooxygenase enzyme system. Leucotrienes are conjugated trienes formed from arachidonic acid in. leucocytes by the Lipoxygenase pathway.

Answer 13

Synthesis of prostaglandins and other compounds

Question 14

A deficiency of EFA causes swelling of mitochondrial membrane and reduction in efficiency of oxidative phosphorylation. This may explain for increased heat production noted in EFA deficient animals.

Answer 14

Structural element of mitochondrial membrane

Question 15

Fats with high content of polyunsaturated fatty acids tends to lower serum level of cholesterol.

Answer 15

strum level or cholesterol

Question 16

Prolongation of clotting time is noted in ingestion of fats rich in EFA.

Answer 16

Effect on clotting time

Question 17

An increase in fibrinolytic activity follows the ingestion of fats rich in EFA.

Answer 17

Effect on fibrinolytic activity

Question 18

Deficiency of EFA produces fatty liver.

Answer 18

Role of EFA in fatty liver

Question 19

is the most abundant polyencic fatty acids present in retinal photoreceptor membranes.

Answer 19

Docosahexaenoic acid (22:6-3)

Question 20

Docosahexaenoic acid (22:6-3) is the most abundant polyencic fatty acids present in retinal photoreceptor membranes. Docosahexaenoic acid is formed from dietary linolenic acid. It enhances the electrical response of the photoreceptors to illumination. Hence linolenic acid is necessary in the diet for optimal vision.

Answer 20

Role in vision

Question 21

the carbon-carbon bonds are all single

Answer 21

Saturated fatty acid

Question 22

This 20-carbon fatty acid’s main function is to produce chemicals called eicosanoids, which help reduce inflammation. EPA:
may also help reduce symptoms of depression

Answer 22

Eicosapentaenoic acid (EPA)

Question 23

A 22-carbon fatty acid, DHA makes up about 8% of brain weight and contributes to brain development and function
Alpha-linolenic acid

Answer 23

Docosahexaenoic acid (DHA)

Question 24

This 18-carbon fatty acid can be converted into EPA and DHA, although the process is not very efficient. ALA appears to benefit the heart, immune system, and nervous system

Answer 24

(ALA)

Question 25

Omega-3 fatty acids may help manage cholesterol, triglyceride, and blood pressure levels

Answer 25

Improving heart health

Question 26

Omega-3 supplements may help manage or prevent depression, Parkinson’s disease, and psychosis in those at risk. However, more research is needed

Answer 26

Supporting mental health

Question 27

Omega-3 fats may help people manage their weight and waist circumference but more studies are needed

Answer 27

Reducing weight and waist size

Question 28

Initial research suggests that consuming omega-3s may help decrease the amount of fat in your liver

Answer 28

Decreasing liver fat

Question 29

have the presence of one or more double bonds in the trans configuration instead of the usual cis cunfiguration

Answer 29

Trans fatty acids

Question 30

Trans fats are made when liquid oils are turned into solid fats like shortening on margarine. These are called

Answer 30

partially hydrogenated oils (PHOs):

Question 31

are triesters of glycerol and long-chain carboxylic acids called fatty acids.

Answer 31

Triglycerides

Question 32

possess the ability to synthesize odd- and branched-chain fatty acids

Answer 32

Bacteria

Question 33

a mixture of triglycerides containing a high proportion of long-chain, saturated fatty acids.

Answer 33

Fat

Question 34

generally solid at room temperature

Answer 34

Animal fats

Question 35

a mixture of triglycerides containing a high proportion of long-chain, unsaturated fatty acids or short-chain, saturated fatty acids.

Answer 35

Oil

Question 36

usually liquids (liquid fats)

Answer 36

Fish and plant fats

Question 37

colorless, odorless, and tasteless

Answer 37

Pure fats and oil

Question 38

Some unsaturated fatty acids (linoleic and linolenic acids) are called?

Answer 38

essential fatty acids

Question 39

carried out on a large scale to produce the solid shortening sold

Answer 39

Hydrogenation

Question 40

is the base-promoted hydrolysis of fats and oils, producing glycerol and a mixture of fatty acid salts called soaps.

Answer 40

Saponification

Question 41

has been used for thousands of years, and saponification is one of the oldest known chemical reactions.

Answer 41

Soap