Dietary Fiber And Polyunsaturated FA

Question 1

Can fiber be digested by mammalian digestive enzymes

Answer 1

No

– but microbes in ruminants can break these down

Question 2

What is the best method for detection of fiber?

Answer 2

Chemical

Question 3

What are soluble fiber types? And what are their sources?

Answer 3

Pectin -fruit and veg
Gums -oat
Mucilages -legumes
Hemicelluloses -psyllium husks

Question 4

What are insoluble fiber types?

Answer 4

Hemicelluloses
Cellulose
Modified cellulose
Lignin (woody plants)

Question 5

Dietary fiber is broken down into short chain fatty acids and gas by???

Answer 5

Bacteria

Question 6

What are the short chain fatty acids? Where are they used as an energy source?

Answer 6

Butyrate, propionate, and acetate

Cells lining the large intestine

Question 7

Short chain fatty acids produce a _______ environment and promote water and electrolyte absorption

Answer 7

Acidic

Question 8

Canine gets __________ % energy from short chain fatty acids

Answer 8

<10

Question 9

What type of fibers are rapidly fermented?

Answer 9

Water soluble –> viscous gels

Readily fermented in large intestine
Bind minerals (cations)
Tend to bind digestive enzymes
Slow nutrient absorption

Question 10

What are the slowly fermented fibers?

Answer 10

Insoluble in water (eg cellulose, soybean or peanut hulls)

Resistant to bacterial fermentation and do not bind digestive enzymes or minerals

Question 11

Weight loss foods should contain (high or low) amounts of fiber?

Answer 11

High

Eg . 
Cellulose 
Guar gum 
Pectin 
Psyllium husks 
Beet pulp

Question 12

What is a non-digestible food that benefits the host by selectively stimulating/inhibiting activity of bacteria

Answer 12

Prebiotics

Question 13

What are dietary sources of prebiotics?

Answer 13

Soybean
Insulin
Raw oat
Unrefined wheat and barley uu

Question 14

Fiber can be used therapeutically for what diseases?

Answer 14

Obesity 
Diabetes mellitus 
Hyperlipidemia 
Normalize intestinal motility 
Trichobezoars 
Colitis 
Constipation

Question 15

When treating constipation with fiber you must ensure the patient is adequately ___________

Answer 15

Hydrated

Question 16

T/F: crude fiber = total dietary fiber

Answer 16

True

Question 17

What is thee difference between facilitative and functional lipids?

Answer 17

Facilitative

• palatability and texture
• dense calorie source, stored as energy
• promote fat soluble vitamin absorption

Functional

• cell regulation or metabolism
• esssential (linolenic acid, a-linolenic acid, arachidonic, eicosaphentanoic, and docosahezenoic)

Question 18

A fatty acid with one double bond is called?

Answer 18

Monosaturated

Question 19

A fatty acid with multiple double bonds is called?

Answer 19

Polyunsaturated

Question 20

How do mammals synthesize fatty acids?

Answer 20

Glucose and/or amino acids -> acetyl CoA -> saturated fatty acids

Question 21

Are enzymes for lipid biosynthesis more active when consuming at low fat diet OR when consuming high fat diets

Answer 21

Low fat diets (eg herbivores)

In a high fat diet (eg cats and dogs) fats are directly used and stored

Question 22

Where do cats get arachadonic acids?

Answer 22

From spiders!! Jk

From animal tissues -> cats do not have the enzymes to synthesize

Question 23

Linolenic acid can by synthesized into eicosapentaenoic acid and docosahexaenoic acid, if you supply linolenic acid will it be sufficient to supply EPA and DHA needs?

Answer 23

Only about 10% of linolenic acid is made into EPA

If you need EPA you should supply directly (kittens and puppies require this)
Fish oils

Question 24

Linolenic acid if sound in _________________ that are extruded from epidermal keratinocytes

Answer 24

Phospholipid ceramides

Question 25

What is the function of linolenic acid?

Answer 25

Enhance cell adhesion and make a water barrier to the epidermis

Question 26

What is the function of alpha-linolenic acid ??

Answer 26

Contribute to water barrier

Sparing effect on linolenic acid

Question 27

What is the function of arachidonic acid?

Answer 27

Is 20-25% of Fatty acid of cell membrane phospholipids of skin and tissues

Works in the COX pathway as a receptor for ecosanoids –> inflammatory process

Question 28

What is a competitive substitute for arachidonic acid

Answer 28

Eicosapentaenoic acid

Question 29

What are clinical signs of essential fatty acid deficiency?

Answer 29

Poor growth and weight gain
Cutaneous changes
Infertility and poor wound healing

Question 30

T/F: n-3 PUFA are more effective in inhibiting n-6 PUFA metabolism than vice versa

Answer 30

True

Question 31

What is a 20 carbon fatty acid that is synthesized locally in response to their immediate environment

Answer 31

Ecosanoids

Question 32

What are products of cyclooxygenase?

Answer 32

Prostaglandins and thromboxanes

Question 33

What are products of lipoxygenase

Answer 33

Leukotrienes

Question 34

What are the potential clinical benefits of ecosanoids

Answer 34

Immune response-> regulated production and biological function of cytokines

N-3 PUFA generally reduced immune reactivity and are mediated through changes in eicosandoid production

Question 35

What is a good source of n-3 and n-6 PUFA?

Answer 35

Supplant

Natural fish oil concentrate

Question 36

Is flaxseed oil a good source of ecosanoids for cats?

Answer 36

Nope, cannot make flaxseed oil into n-3 therefore not a good source of ecosanoids