Fat

Question 1

DIETARY “FAT”

Answer 1

A) Definition – a categorical reference to lipid in food.

1) Food lipids that are liquid at room temperature are called oils, whereas those that are solid are called fats.

Question 2

Most common class of food lipids

Answer 2

Triacylglycerol

Question 3

Dietary energy: Fat has ___ times more ME as protein and carbohydrate on a weight basis

Answer 3

2.25, because of this fat is used to increase dietary energy density for certain conditions

Question 4

Dietary essential fatty acids

Answer 4

Specific fa’s- alpha-linoleic, arachidonic, omega-3- fa’s; Basis of need for lower limit of dietary fat (2-5% diet weight)

Question 5

Dietary fat required for ____ absorption

Answer 5

fat soluble vitamin (A,D,E,K)

Question 6

Fat of animal origin increases____

Answer 6

palatability

Question 7

Fat on ruminant diets:

Reduces______ and limited to ____ because of rumen microflora depression

Answer 7

dustiness, ~5%

Question 8

Essential fatty acids are specific _____ fatty acids of ____ that are identifed by their ____ and the position and number of ____

Answer 8

polyunsaturated; 18 C and longer; chain length; double bonds

Question 9

“Omega” or methyl-end (n) numbering system

Answer 9

20:4n-6
first number indicates number of carbon atoms, the 4 after the colon indicates the # of double bonds, the omega or n series designation indicates the first position the double bond from the methyl end or the end (omega) position

Question 10

Animal do not have ____ than can introduce double bonds beyond 9 carbons from the carboxyl end of the fatty acid

Answer 10

Desaturases

Question 11

Animals have physiological needas for 18 C and greater fatty acids with double bonds at the n-3 and n-6 positions because….

Answer 11

such fatty acids cannot be synthesized by animals

Question 12

Fatty acids of 18, 20 and 24 carbons may be formed from… By what enzymes?

Answer 12

shorter length dietary and “de novo” synthesized fatty acids; elongases

Question 13

Essential fatty acid required in largest amount in diet

Answer 13

Linoleic acid C18:2n6

Question 14

Conditionally essential fatty acid when synthesis from linoleic acid is low; ESSENTIAL IN CATS

Answer 14

Arachidonic acid C20:4n6

cats lack sufficient delta-6 desaturase activity for synthesis from linoleic acid

Question 15

Arachidonic acid is conditionally essential in __- of some species

Answer 15

neonates

Question 16

Arachidonic acid does not occur in ____

Answer 16

plants