Anaimal Nutrition Lipids

Front 1

What are lipids?

Back 1

A diverse group of compounds, NOT SOLUBLE IN WATER, but soluble in non-polar organic solvents

Front 2

Lipids are usually related to?

Back 2

Fatty acids

Front 3

What is a fatty acid?

Back 3

Long chain of carbon atoms with a terminal methyl group and carboxyl group

Front 4

Is a single bond saturated or unsaturated?

Back 4

Saturated

Front 5

Is a double bond saturated or unsaturated?

Back 5

Unsaturated

Front 6

Degree of saturation of fatty acids have a mjor influnce on

Back 6

melting point,
chemical properties,
nutritional value

Front 7

At room temp., no double bonds are

Back 7

solid

Front 8

At room temp, with double bonds...

Back 8

liquid

Front 9

Is it important where a double bond is in a fatty acid?

Back 9

Yes

Front 10

The double bond in fatty acids

Back 10

bends the molecule

Front 11

Saturated fatty acid molecules are..

Back 11

straight

Front 12

Fish oils have..

Back 12

long chains and are unsaturated

Front 13

What are non-glycerol based lipids?

Back 13

Sphingomyelins,
cerebrosides,
waxes,
steroids,
terpenses,
prostaglandinds

Front 14

Are compound lipids nutritionally important?

Back 14

Not nutritionally important, but important in maintaining cell membrane acitivity

Front 15

Fatty acids in nature are usually found as...

Back 15

Triacylglycerol

Front 16

Lecithin is...

Back 16

a complex lipid,
emulsifies fats,
is widley found in nature

Front 17

Long chain fatty acids, saturated (sterols, vitamins) are...

Back 17

non polar solutes,
LOWER DIGESTIBILITY,
poor solubility in bile salt solution,
limited entry into micellar phase

Front 18

Medium chain fatty acids, long chain unsaturated fatty acids, and monoglycerides

Back 18

polar solutes,
better digested,
swlling amphiphiles,
enter micellar phase,
promote entry of non-polar solutes into micellar phase

Front 19

What is the main problem with lipids?

Back 19

they do not dissolve in water and digestion takes place in an aqeous environment

Front 20

How are fats digested?

Back 20

Enzyme lipase is responsible for digesting fats, but ONLY FATS THAT ARE EMULSIFIED

Front 21

Unsaturated fatty acids vs. saturated fatty acids: which ones chemical structure has better digestibility?

Back 21

Unsaturated fatty acids

Front 22

Triglycerides vs. free fatty acids:
which ones chemical structure has better digestibility?

Back 22

Triglycerides

Front 23

Young mammal (pre-weaned) have

Back 23

limited bile and pancreatic lipase production, fastric lipase (secreted by serous glands of tongue) ->FA Absorbed by stomach, some TAG and DAG from gastric lipase enters small intestine

Front 24

Is milk fat highly emulsified?

Back 24

Yes

Front 25

What is necessary (un young and adults) to hydrolyze TAG/DAG?

Back 25

Ca++

Front 26

What is a micelle a combination of?

Back 26

Bile salts and enzymes

Front 27

What do micelles do?

Back 27

Get around problem of fats not dissolving in water

Front 28

What acts as surface in micelle?

Back 28

Lipases

Front 29

What is one reason bile salts are efficient?

Back 29

They are re-circulated back into upper region of small intestine (enter-hepatic circulation)

Front 30

The chemical structure of fats/oils has a major affect on

Back 30

energy-yeilding value

Front 31

The n or w number for essential fatty acids refers to?

Back 31

number of carbon atoms between last double bond and terminal methyl group

Front 32

n-6 and n-3 fatty acids are..

Back 32

precursors for a number of higher order fatty acids and key metabolites (ex. prostaglandins), involved in maintaining cell membrane integrity

Front 33

n-3 and n-6 fatty acids

Back 33

must be in diet in adequate amounts,
can not be synthesized from any other fatty acid families

Front 34

What is the basic sustrates for fatty acid conversion?

Back 34

alpha linoleic (n-6) or alpha linolenic (n-3)

Front 35

What are the 2 key enzyme systems in fatty acid conversion?

Back 35

1. chain elongation
2. desaturation

Front 36

In fatty acid conversions there is...

Back 36

no competition between substrates,
no deficiency of enzyme cofactors,
efficiency is good,
presumably the enzymes are present

Front 37

What are the problems with fatty acid conversions?

Back 37

fatty acids that are not essential fatty acids compete with essential fatty acids for enzymes (alpha 6 desaturase also accepts oleic nonessential..excess oleic can creat deficiency of EFA),

efficiencies in conversions further up the path are much better

Front 38

It is pointless feeding ____________ for EFA requirements

Back 38

linseed oil

Front 39

Eicosapentanoic is found only in

Back 39

fish oil/animal fats

Front 40

Zn and Fe are involved in

Back 40

chain elongation and desaturation

Front 41

Zinc deficiency can reduce

Back 41

alpha 6 desaturase acitivty (ancillary role in EFA metabolism) (not a direct co-factor and part of the enzyme)

Front 42

Zinc deficiency is exacerbated by....

Back 42

high genetic potential,
presense of dietary fats and oils (eg. non EFAs) that inhibit EFA metabolism,
high dietary Ca (inhibits Zn absorption and metabolism, promotes metabolism of monounsaturated fatty acids)

Front 43

Requirements for EFAs....

Back 43

very little data on quantitative requirments

Front 44

The recommened ratio of n-6 to n-3 EFAs is...

Back 44

5:1

Front 45

Benefits for higher EFAS / ratio of n6:n3 are..

Back 45

preformance,
reproduction,
immune status,
appearance

Front 46

Are long chain EFAs stable?

Back 46

No (the more unstable the greater number of double bonds)

Front 47

What are the solutions to make long chain EFAs less unstable?

Back 47

(during production/storage):
-microencapsulation
-antioxidants (ex. vitamin E):must be added as early as possible in processing *OXIDATION CAN NOT BE REVERSED*,
do not use PV as a means of assesing oxidation (use active oxygen method, TOTOX value)