Animal Nutrition Test 3 Flashcards Preview

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Flashcards in Animal Nutrition Test 3 Deck (212):
1

Carbs are:

Polyhydroxyaldehydes or polyhydroxyketones, or substances that yield them on hydrolysis

2

Gum is a:

Carb

3

What percentage of an animals body is carbs?

Less than 1%

4

Carbs form what percent of the dry weight of forages? Seeds?

70%, up to 85%

5

Feeds classified as carbs generally occupy what percent of the diet on a weight basis?

Over 80%

6

Major function of carbs:

Dietary energy

7

Energy reactant in photosynthesis

686 Kcal

8

Chemical composition by % molecular weight of carbs is:

C: 40%
H: 7%
O: 53%

9

How much more energy/calories does fat contain than carbs on an equal weight basis?

2.25x

10

Classify the following carb as either a monosaccharides (pentose or hexose), disaccharide, trisaccharide, polysaccharide (pentosan or hexosan), or mixed polysaccharide.

Arabinose

Pentose monosaccharide

Polysaccharides found in: araban and pectin



11

Classify the following carb as either a monosaccharides (pentose or hexose), disaccharide, trisaccharide, polysaccharide (pentosan or hexosan), or mixed polysaccharide.

Xylose

Pentose monosaccharide

Found in polysaccharides, corn cobs, and wood

12

Classify the following carb as either a monosaccharides (pentose or hexose), disaccharide, trisaccharide, polysaccharide (pentosan or hexosan), or mixed polysaccharide.

Ribose

Pentose monosaccharide

Found in nucleic acids NOT IN POLYSACCHARIDES

13

Classify the following carb as either a monosaccharides (pentose or hexose), disaccharide, trisaccharide, polysaccharide (pentosan or hexosan), or mixed polysaccharide.

Glucose

Hexose monosaccharide

Found in disaccharides (literally all of them that I list), polysaccharides, honey, fruits, and plant sap

14

Classify the following carb as either a monosaccharides (pentose or hexose), disaccharide, trisaccharide, polysaccharide (pentosan or hexosan), or mixed polysaccharide.

Fructose

Hexose monosaccharide

Found in disaccharides and inulin

The sweetest monosaccharide, the only ketone hexose

15

Classify the following carb as either a monosaccharides (pentose or hexose), disaccharide, trisaccharide, polysaccharide (pentosan or hexosan), or mixed polysaccharide.

Galactose

Hexose monosaccharide

Found in milk (lactose disaccharide)

16

Classify the following carb as either a monosaccharides (pentose or hexose), disaccharide, trisaccharide, polysaccharide (pentosan or hexosan), or mixed polysaccharide.

Mannose

Hexose monosaccharide

Found in polysaccharides

17

Classify the following carb as either a monosaccharides (pentose or hexose), disaccharide, trisaccharide, polysaccharide (pentosan or hexosan), or mixed polysaccharide.

Sucrose (table sugar)

Disaccharide, glucose + fructose

Found in sugar cane and beets

18

Classify the following carb as either a monosaccharides (pentose or hexose), disaccharide, trisaccharide, polysaccharide (pentosan or hexosan), or mixed polysaccharide.

Maltose

Disaccharide, glucose + glucose (4-a linkage)

Found in starchy plants and roots

19

Classify the following carb as either a monosaccharides (pentose or hexose), disaccharide, trisaccharide, polysaccharide (pentosan or hexosan), or mixed polysaccharide.

Lactose

Disaccharide, glucose + galactose

Found in milk

20

Classify the following carb as either a monosaccharides (pentose or hexose), disaccharide, trisaccharide, polysaccharide (pentosan or hexosan), or mixed polysaccharide.

Cellobiose

Disaccharide, glucose + glucose (4-B linkage)

Found in the fibrous portion of plants

21

Classify the following carb as either a monosaccharides (pentose or hexose), disaccharide, trisaccharide, polysaccharide (pentosan or hexosan), or mixed polysaccharide.

Raffinose

Trisaccharide/oligosaccharide, glucose+fructose+galactose (sucrose+galactose)

Found in certain varieties of eucalyptus, cottonseed, and sugar beets (sucrose is found in sugar beets too!)

22

Classify the following carb as either a monosaccharides (pentose or hexose), disaccharide, trisaccharide, polysaccharide (pentosan or hexosan), or mixed polysaccharide.

Araban

Polysaccharide pentosan made of arabinose

Found in pectins (just like arabinose)

23

Classify the following carb as either a monosaccharides (pentose or hexose), disaccharide, trisaccharide, polysaccharide (pentosan or hexosan), or mixed polysaccharide.

Xylan

Polysaccharide pentosan made of xylose

Found in corn cobs and wood (just like xylose)

24

Classify the following carb as either a monosaccharides (pentose or hexose), disaccharide, trisaccharide, polysaccharide (pentosan or hexosan), or mixed polysaccharide.

Starch

Polysaccharide hexosan made of glucose (maltose)

Found in grains, seeds, tubers, rhizomes, and fruits

25

Classify the following carb as either a monosaccharides (pentose or hexose), disaccharide, trisaccharide, polysaccharide (pentosan or hexosan), or mixed polysaccharide.

Dextrin

Polysaccharide hexosan, breakdown unit of starch so 3-8 units of glucose

26

Classify the following carb as either a monosaccharides (pentose or hexose), disaccharide, trisaccharide, polysaccharide (pentosan or hexosan), or mixed polysaccharide.

Cellulose

Polysaccharide hexosan made of 3,000-5,000 units of glucose (cellobiose)

Found in the cell wall of plants (the fiber found in the stem, leaves, and roots)

27

Classify the following carb as either a monosaccharides (pentose or hexose), disaccharide, trisaccharide, polysaccharide (pentosan or hexosan), or mixed polysaccharide.

Glycogen

Polysaccharide hexosan made of glucose so it's very similar to starch

Found in the liver and muscle of animals

28

Classify the following carb as either a monosaccharides (pentose or hexose), disaccharide, trisaccharide, polysaccharide (pentosan or hexosan), or mixed polysaccharide.

Inulin

Polysaccharide hexosan made of fructose

Found in potatoes, tubers, and artichokes

29

Classify the following carb as either a monosaccharides (pentose or hexose), disaccharide, trisaccharide, polysaccharide (pentosan or hexosan), or mixed polysaccharide.

Hemicellulose

Mixed polysaccharide that is a mixture of pentoses (mostly) and some hexoses

Found in fibrous plants

30

Classify the following carb as either a monosaccharides (pentose or hexose), disaccharide, trisaccharide, polysaccharide (pentosan or hexosan), or mixed polysaccharide.

Pectins

Mixed polysaccharide that is a mixture of pentoses, hexoses, and salts of complex acids

Found in citrus fruits and apples

31

Classify the following carb as either a monosaccharides (pentose or hexose), disaccharide, trisaccharide, polysaccharide (pentosan or hexosan), or mixed polysaccharide.

Gums (partially oxidized to acids)

Mixed polysaccharide made up of pentoses and hexoses

Found in acacia trees and some plants

32

Oligosaccharide has how many sugars?

3-10

33

Glycose=

A monosaccharide

34

What are the only monosaccharides that occur in free form in nature?

Glucose and fructose

Both are WATER SOLUBLE and sweet

35

Are pentoses dietary essentials?

No, they can be made from hexoses, protein, and glycerol

36

What is ribose found in?

ATP, ADP, riboflavin, and RNA

37

Digestibility of hemicellulose

Partially digestible because of acidic conditions in the stomach

Insoluble in boiling water, soluble in dilute alkali, readily degraded by dilute acid

Mammals don't make enzymes to digest it

Closely associated with lignin in the cell wall

38

Most abundant carbs found in nature

Hexoses

39

2 functions of hexosans

1) Make up a major part of the animal and human diet (starch and cellulose)

2) they serve as both fuel and intermediates in metabolic pathways

40

2 functions of glucose in metabolism:

Glucose is the major carb used for energy at the cellular level. All digested dietary carbs are converted to glucose, making it a dietary essential

Major circulating carb in the blood

41

Haworth perspective

The position of the H and OH groups on C1 determines if the compound is in alpha or beta form

42

Where are derivatives of galactose found?

Brain and nervous tissue

43

What 1 species can't use galactose?

Poultry, they don't have lactase

44

Form of inulin found in plants?

Mannans

45

Order these from sweetest to nonsweetest:

Sucrose
Glucose
Fructose
Lactose
Maltose
Saccharine
Aspartame

Saccharine, aspartame, fructose, sucrose, glucose, maltose, lactose

46

Other sources of sucrose besides sugar cane and sugar beets?

Ripe fruits, tree sap (maple sugar), vegetable, and sorghum (molasses)

47

What animal doesn't have sucrase activity?

Baby pigs until 7 days old

48

How does maltose get its name?

It's made commercially from starch via the malting process

49

What things can split cellobiose?

Microbial enzymes, fungal enzymes, or acid

50

What proportion of the solids in milk is lactose?

1/2

51

Methods of alleviating lactose intolerance?

1) put B-galactosidase in milk before drinking it (break the bond and it'll taste sweeter)

2) drink lactobacillus acidophilus milk (makes a different bacterial population in large intestine)

52

In cultured products such as yogurt, what percentage of lactose is fermented to lactic acid?

60%, better for lactose intolerant people

53

In what form do animals obtain most of their dietary carbohydrate?

Polysaccharide

54

Why do fruits get sweeter when ripening?

Conversion of starch to sugars

55

Amylose makes up what percentage of starch in most plants?

25-30%

56

Amylopectin makes up what percentage of starch in most plants?

70-75%

57

Characteristics of amylose

Soluble in hot water
Straight chains of glucose
a-1,4-linkage only
Helix

58

Characteristics of amylopectin

Insoluble in water
Branched chains of glucose (more sites for enzymes to attach so more digestible than amylose)
a-1,4-linkage AND a-1,6 cross linkages
Phosphorous found
One of the largest MW in nature

59

Frequency of phosphorus found in amylopectin?

1 in every 400 glycose units

60

Molecular weight of amylopectin?

A million or more

61

When you hydrolyze or apply high heat to starch, what do you get?

Dextrin (3-8 glucose units)

62

Glycogen is what percent of weight weight of liver?

Usually 2-8% in most species, can be up to 10%

63

Is glycogen water soluble?

Yes (pure polymer of glucose, which is water soluble)

64

What level will liver glycogen be at after 24 hours of fasting?

0

65

Most abundant substance in the plant kingdom?

Cellulose

Also the single most abundant organic compound in the world

66

Cellulose occupies what percentage of the dry matter of all vegetation?

About 50%

67

Is cellulose soluble in water?

No

68

Name the 3 heteropolysaccharides

Pectin, hemicellulose, and gums

69

Composition of hemicellulose

60-80% xylose and arabinose (pentoses), galactose, glucose, and others

70

Hemicellulose covalently links to ____ and then hydrogen bonds to _____

Pectin, cellulose

Remember lignin is close by too

71

Digestibility of pectin

Depends on microbes so questionable value to monogastrics

Much of it is digested, even by humans, however. So it must be a readily fermentable fraction for the microbes for to be true

72

Function of pectin

Holds water!

Used as diarrhea medicine, given to cows in the form of beet pulp to make ruminoreticulum expand and cow has spring of rib

Also used in dairy rations as fiber to balance fiber fraction

73

Pectin is similar to:

Hemicellulose

74

What is starch's job?

Energy reserve in roots, tubers, and seeds

This is why glycogen is called "animal starch" because it's an energy reserve in animals

75

How much lipid is in most diets?

Usually less than 5%, carb is much more plentiful energy form in food

76

Ultimate source of energy for most animal cells?

Glucose

77

What classification of carbs can be absorbed form the gut?

Monosaccharides

78

Digestion of amylose and amylopectin

Digested by the same enzymes because hydrolysis of both to glucose is similar

79

Lignin is a mix of:

Polymers and phenolic acid

80

Characteristics of lignin

Increases with plant age

Found with hemicellulose and cellulose in cell walls

Effects bioavailability of cellulose and hemicellulose for microbial use

81

Sources of lignin

Legumes are high in lignin

Grasses are intermediate in lignin

Veggies and cereal are low in lignin

82

Can pigs use VFAs?

Yes, microbes in large intestine can make VFAs from fiber

These VFAs can provide some of the energy required for maintenance

May be as much as 30% of the digestible energy intake due to a cellulolytic enzyme in the pig large intestine

83

3 major groups of microbes found in the rumen?

Small bacteria (largest in microbial mass), ciliated protozoa, and fungi

84

Areas of monosaccharide absorption

Duodenum and Jejunum > ileum> stomach and large intestine

85

Disaccharidase deficiency

Serious GI upsets

No sucrase in young mammals and ruminants = severe diarrhea or death when fed large amounts of sucrose

No lactase in adult pigs and some humans= diarrhea when fed lactose

Fewer starch-splitting enzymes in ruminants than nonruminants

86

Absorption rate of soluble carbs? Does it vary greatly from animal to animal?

90%, no

87

Factors affecting the rate of digestion of starch

Particle size, nature of the starch (amylose vs amylopectin), interactions of starch with proteins and fat, and the presence of antinutrients (tannins, phytate, saponins, and enzyme inhibitors)

88

What happens to monosaccharides other than glucose after absorption?

If they weren't turned into glucose by the mucosa cell during absorption, then they'll be turned to glucose in the liver. The glucose can either be turned to fat or glycogen if it's being stored, but fat is much more likely than glycogen

89

Purpose of glycogen

It can be hydrolyzed RAPIDLY back to glucose (fat is slower!) or vice verse to keep circulating blood glucose within a narrow range

90

Glycogenesis

Glucose --> glycogen

91

Glycogenolysis

Glycogen --> glucose

92

What hormones control blood sugar regulation?

Insulin and glucagon from the pancreas

93

Oxidative phosphorylation

Using the energy of oxidation (giving electrons from a substrate to oxygen) to phosphorylate ADP to ATP

Driving force for absorption of nutrients from the GI tract and synthesis of the 4 macromolecules

94

Gluconeogenesis

When the body tissues (liver and sometimes kidneys) make glucose from noncarbs like lipids and amino acids.

95

Glucogenic

When metabolized it gives rise to a net increase in glucose

96

Amino acids that are glucogenic only:

All the nonessential amino acids (everything that's not MATT HILL VP! Remember arg, three Tylers? Let's drown him in phenol)

Some of the essential amino acids: Met, His, Cys, Val, Thr, Trp, Arg (I met his sister Valerie three times, she tripped down the stairs and yelled arg)

97

Amino acids that are both glucogenic and ketogenic

Tyr, Ile, Phe, Lys (Tyler said, "I'll make you feel like you have lice")

98

Amino acid that is ketogenic only

Leucine

99

What happens when ingestion of carbs exceeds current needs?

Glucose --> pyruvate --> fat

100

The amino acids used for gluconeogenesis or for energy enter the TCA as:

Acetate, pyruvate, or a-ketoglutarate

101

Two fates of pyruvate

Converted to acetyl CoA in the mitochondria

Reduced to lactate in the cytoplasm by oxidation of NADH

102

How much total energy is released in the conversion of glucose to CO2 and water?

673 kcal (remember: 686 reactant for photosynthesis)

103

What is the efficiency of the conversion of the free energy of oxidation of glucose?

40-60%

104

What animals does ketosis affect?

Lactating cattle and pregnant sheep

also swine during starvation, pregnant ewes, and dairy cows with B12 deficiency

105

Define ketosis

An excess of ketones (acetone, acetoacetate, and B-hydroxybutyrate) in TISSUES bc of a disorder in CARB OR LIPID (energy) metabolism

Ketonemia/acetonemia = increased ketones in BLOOD

Ketonuria = increased ketones in URINE

Treat by restoring normal blood glucose because CHARACTERIZED BY LOW BLOOD GLUCOSE

106

Rumen microbes have enzymes that can hydrolyze cellulose present in cell walls in:

Leaf, stem, and outer bran layer of seeds

107

What can termites do

Break down lignin (chief constituent of trees)

108

Extensins

PROTEINS that are in the structural components of plants. Proteolytic enzymes can't degrade them so they have low bioavailability

109

Van Soest

Neutral detergent gives NDF (cellulose, hemicellulose, and lignin)

Acid detergent gives ADF of lignin and cellulose and ADS of hemicellulose

H2SO4 digestion gives insoluble lignin and soluble cellulose

Hemicellulose > cellulose > lignin based on solubility

110

How might recombinant DNA technology assist in improving fiber digestion?

Cloning cellulases to change microbial activity so that it can break the cellulose-hololignin bond

Produce superior cellulolytic microbes

111

Is lignin a carb?

No

112

Amorphous

No particular structure

Lignins structure depends on the plant species

113

Lignin

Resistant to degradation by acids or alkali

Reduces digestibility of PROTEIN too!

114

When does the amount of lignin in a plant escalate?

Around the time of setting of seed. Thus, many forages are harvested when they're beginning to bloom or right before

115

What things can break the bond between lignin and other things AND degrade the lignin itself?

AEROBIC microbes and fungi

Strong alkali can only break the bond- it leaves the lignin intact

Note: rumen organisms can't do either!

116

Carb fractions found in the stem, leaf, and seed?

Fiber, monosaccharide, and starch

117

Fiber, monosaccharide, and starch in the stem

Fiber: lots of it
Monosaccharide: a little being transported from leaves to seeds
Starch: none

118

Fiber, monosaccharide, and starch in leaves

Fiber: some
Monosaccharide: lots from photosynthesis
Starch: none

119

Fiber, monosaccharide, and starch in seeds

Fiber: some (but not much) because of hull/seedcoat
Monosaccharide: some (but not much) as precursor of starch
Starch: lots to nourish the seedling

120

What percentage of grains is starch?

60-80%

121

How digestible is starch?

80-90% digestible

122

What percentage of grains is cell wall?

Less than 15%

123

Cell wall and lignin content of green pasture vs dormant pasture

Green pasture has less cell wall content and less lignin

Dormant pasture has more of both

124

Cell wall and lignin content of hay vs silage

Exactly the same for both

125

What percentage of a hull/seedcoat is cell wall?

60-80%

126

How digestible are hulls/seedcoats?

Highly digestible, 60-80% because they only have 2-3% lignin

127

3 things are lipids have in common

1) insoluble in water but soluble in organic solvents
2) they are actually or potentially fatty acid esters
3) utilized by living organisms

128

Elemental composition of lipids by % MW:

C: 77%
H: 12%
O: 11%

129

Classifications of the lipids of nutritional importance:

Simple lipids, compound lipids, derived lipids, sterols, and terpenes

130

Simple lipids

Fatty acids+alcohols

Fats and oils (these make up largest fraction of lipids in most material), and waxes (waxes are the only ones with an alcohol different than glycerol. They're unimportant and not used well by body)

131

Energy value of fats vs carbs

9.45 kcal/gram for fat, 4.1 kcal/gram for carbs

132

Compound lipids

Fatty acid + lipid + SOMETHING ELSE

Phospholipids, glycolipids (sometimes contain N), and lipoproteins. The last two are used for metabolism and are scarce

133

Derived lipids

Substances derived from simple or compound lipids by hydrolysis

Fatty acids, glycerol, and other alcohols

134

Sterols

Lipids with complex phenanthrene-type structure (used for metabolism, scarce)

135

Terpenes

Have isoprene-type structure

Unimportant, not used well by the body

136

Most important lipids in nutrition

Fatty acids, glycerol, mono-, di-, and triglycerides, and phospholipids

137

All neutral fats contain:

Glycerol

138

Chain length of fatty acids

Can be from 2-24 carbons long (even number), but the most common fatty acids have 16-18 carbons

139

Naturally occurring variations in fatty acids:

Odd number of carbons, branched chains, or hydroxy acids

These are less plentiful but found in ruminants due to microbial synthesis

140

Almost all naturally occurring lipids contain one or more:

Fatty acid

141

Which are more reactive: saturated or unsaturated fatty acids?

Unsaturated bc of the double bond

142

Omega-3 and omega-6 fatty acids

Long chain unsaturated fatty acids in depot fats (adipose) of fish

They consist of: linoleic acid, eicosapentaenic acid, and docosahexaenoic acid (DHA)

Where double bond is is critical to biological activity

143

Carbons and double bonds in linoleic acid?

18 C, 3 double bonds

144

Carbons and double bonds in eicosapentaenic acid?

20 carbons, 5 double bonds

145

Carbons and double bonds in DHA?

22 carbons, 6 double bonds

146

What do fish oils protect against?

Atherosclerosis (CHECK THIS ONE)

147

Benefits of CLA isomers to humans?

Protect against cancer, diabetes, atherogenesis, and obesity

Modulates immune function and bone growth

148

Primary form of lipid in nature

Mono di and triglycerides

149

2 factors that determine physical and chemical properties of fatty acids:

Chain length and degree of unsaturation

150

Liquid fat at room temperature

Unsaturated or saturated with a chain length less than 10

More than 10 saturated is solid

151

3 tests used to characterize the chemical properties of fats:

Saponification number: chain length

Reichert-Meissl (RM) number: proportion of VFAs present

Iodine number: degree of hydrogenation/saturation

152

Common characteristic of a phospholipid

Ester phosphorus

153

Function of phospholipids

Cell organization, also involved in mitochondrial enzyme systems and lipid transport because of their emulsifying properties

154

Lecithin

White, waxy phospholipid that oxidizes to brown in the presence of oxygen

Basically phosphatidyl CHOLINE

Keeps oils and water together (mayonnaise and milk)

155

Steroids and sterols are derivatives of:

Cyclopentanoperhydrophenanthrene (phenanthrene ring)

156

Erogsterol + sunlight =

Vitamin D

157

In what locations are steroid hormones made from cholesterol?

Adrenal cortex, gonads, corpora lutea, and placenta

158

What are adrenal steroids involved in?

Carb and protein metabolism, fluid and electrolyte balance, blood pressure regulation, stress resistance, and more

159

What are estrogens and progesterones involved in?

Regulate estrus, reproductive cycles, influence protein and nucleic acid and lipid metabolism, and regulate normal bone metabolism

160

What are androgens involved in?

Make sex hormones responsible for secondary sex characteristics, sperm maturity, activity of accessory glands of the genital tract, and promotion of N retention

161

Ralgro

Pseudosterol used as a growth implant in beef cattle

162

4 major functions of lipids

Energy supply, EFAs, carry fat soluble vitamins, and components of membranes

163

Arachidonic acid is the precursor of:

Prostaglandins

These are are a type of eicosanoid. Prostaglandins have many metabolic purposes such as lowering blood pressure, stimulating muscle contraction, inhibiting norepinephrine-induced release of fatty acids from adipose, and modulating immune function.

164

Which species requires dietary arachidonic acid?

Cat

165

Function of EFA

Not completely understood, but they are major parts of phospholipid and cholesterol esters that play a part in cell membranes and lipid transport moieties

166

EFA deficiency symptoms in monogastrics

Dull hair coat with possible loss
Scaly skin
Necrosis of tail
Failure to grow
Affected reproduction and lactation
Eventual death

167

3 Sources of fats in livestock diet

Plants, pure sources of fat, and protected fat

168

Where do we primarily find fats in plants?

Seeds

Oilseeds such as soybeans, cottonseeds, and mung beans contain from 18-25% lipid

169

Grain is the other source of fat in plants (besides seeds). What is the lipid content of corn, milo, wheat, etc?

2-4%

170

Pure sources of fat for humans

Soybean oil, cottonseed oil, corn oil, etc

171

Pure sources of fat in livestock rations

Tallow from beef and lard from hogs

172

The lipids found in feedstuffs are what percent digestible?

Normally greater than 80% digestible. Exceptions include wax and cutin

173

How much fat digestion occurs in the stomach?

Not much because gastric lipase has a higher optimal pH than the acidic conditions of the stomach

More important in the young where the stomach pH is higher and the fats in milk are already emulsified (lecithin)

174

What 2 things increase the activity of pancreatic lipase?

Calcium and the bile salts (emulsify fats into water bc lipase is water soluble)

175

Most dietary fat is in what form?

Triglycerides. These are water-insoluble so they are emulsified in the stomach and further in the small intestine. This is a COARSE emulsion accomplished by peristaltic contractions

176

Where does pancreatic lipase work on the emulsion particle? How does bile help the lipase?

At the oil-water interface.

Bile helps form the emulsion droplets and also helps to orient the lipase with the triglycerides for hydrolysis

177

Which positions does lipase free the fatty acids from the TG?

1 and 3

178

Which position does lipase free the fatty acid from the phospholipid?

From the 1 position. Only a lysolecithin is left

179

The bile acids are more effective in the presence of

Monoglycerides and lysolecithin. Therefore the digestion products promote further digestion

180

Overview of absorption of fat

Bile acids and monoglycerides form micelles. These take up fatty acids (>12) and degrade them. The micelle then goes to the brush border of the jejunum (which is aided by the peristaltic contractions of the gut) and is absorbed into the mucosa cell. Here, monoglycerides and made back into TGs. Next, a chylomicron is made and transported out of the cell via osmotic pressure into the central lacteal of the lymphatic system, to the thoracic duct at the right atrium, and to the body.

181

In the conversion of fats from an emulsion droplet to a micelle, the diameters of the particles is reduced ____ times and the surface area is increased over ____ times

100, 10,000

182

Some bile salts are also absorbed in the jejunum. Most are absorbed in the ileum. This system is ____ efficient.

95% efficient

183

Chylomicron composition:

Triglyceride: 80%
Cholesterol esters: 9%
Phospholipid: 7%
Cholesterol: 2%
Protein: 2%

184

How to make fats from carbs

Glucose to pyruvate to acetyl CoA, which can either go to the TCA for energy production or undergo lipogenesis to make SATURATED fatty acids. These then become unsaturated and are used to make TGs, phospholipids, etc.

To get a fatty acid (either saturated or unsaturated) back to acetyl CoA again, do beta oxidation (take 2 carbs off at a time at the carboxyl end until it's degraded)

185

Whole plants are at a maximum up what percent lipids?

5%

186

2 lipids consumed predominantly from ruminants:

TG from the seeds and galactolipids from the leaves

187

In the rumen, glycerol is fermented to yield ____

Propionic acid

188

What percent of the fats in beef are saturated?

50%

189

Which fatty acids are absorbed by rumen microbes?

Short chain only!

Remember all fatty acids are made saturated in the rumen

Short chain can also be absorbed in rumen or passed down the tract.

190

Fate of long chain fatty acids in the rumen

They form water-soluble salts (soaps) and pass on for absorption in the small intestine

-not absorbed in rumen or used by microbes! Just pass on in the form of soaps

191

What controls adipose tissue?

Nervous and endocrine system, so there's nerves and blood in adipose

192

As the percent of fat in the body increases, the percent of water in the body:

Decreases

193

Lipid concentration in milk

1.5%-50% in seals

Nearly all milk lipid is TG (mammary glands actively make TG and secrete it into milk)

194

Sources of fatty acids in milk:

Circulating TG

Circulating nonesterified fatty acids originating in adipose tissue

De novo fatty acid synthesis in mammary gland

195

Principal fatty acid precursor in monogastrics

Glucose (turns into acetyl CoA to undergo lipogenesis to make saturated FAs to make unsaturated)

196

Principal fatty acid precursors in ruminant mammary gland

Acetate and much smaller amounts of a-hydroxybutyrate (remember acetate is the precursor of milk fat! So we have to keep forage levels high)

197

Where are fatty acids made

The microsome

198

Overview of fatty acid synthesis

Made from acetyl CoA (from carbs, amino acids, or fats)

The carboxyl end of one acetate (from acetyl-CoA) joins the methyl end of another. This repeats to eventually make palmitate, and then other fatty acids are made by modifications of palmitate

199

Procedures to generate other fatty acids from palmitate?

Elongation, desaturation, and hydroxylation

200

TG degradation

Either oxidized in place or transported to other tissues as albumin-fatty acid complexes for oxidation there

Liver, heart, and resting skeletal muscles all rely on fatty acid oxidation for energy (ATP)

201

Where does the glycerol from TG degredation go?

Liver, where it can either be used for energy or converted to glucose

202

Fates of acetyl CoA

Entry into TCA
Synthesis of long chain fatty acids
Acetylation reactions
Steroid synthesis
Ketone body formation

203

Exercise increases ____ levels

HDL, which is poorly associated with heart disease (LDL is)

204

Eating beef promotes more ____ than _____

HDL than LDL

205

What percent of the population will benefit from diet alterations?

2%

206

Supplementation with _____ Will prevent arteriosclerosis?

Vitamin E, it's an antioxidant so it prevents the oxidation of lipids while they're circulating in the blood, which prevents arteries from being damaged and therefore makes them less susceptible to plaque lay down

207

Ketogenesis

Continuous process, normally the ketones are removed rapidly from the blood by muscle

They are used to supply energy

208

Normally fat constitutes about __ of the wet weight of the liver, but it can be up to ____ or more in pathological conditions

5%, 30%

209

Causes of fatty livers

High fat or high cholesterol diet
Increased liver lipogenesis caused by excessive carb or excess intake of certain B vitamins
Increased mobilization of lipids from adipose tissue caused by diabetes
Starvation
Hypoglycemia
Increased hormone output (growth hormone, adrenal corticotrophic hormone, adrenal corticosteroids)
Decreased transport of lipids from the liver to other tissues caused by deficiencies in choline, pantothenic acid, inositol, protein, or certain amino acids (met and thr)

210

Atherosclerosis

NOT ARTERIOSCLEROSIS

Characterized by progressive degenerative changes in the blood vessels and heart of humans and animals

Associated with high serum cholesterol concentration (saturated fats raise it and eating cholesterol)

LDL increases risk, HDL reduces it


211

Average American (M+P)/S is _____

0.5:1

As this ratio goes up, less plasma cholesterol

212

Omega-3's do what to the clotting time of blood?

Increase it, so it protects against the atherogenic process