Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Nutrition > Carbohydrates > Flashcards

Carbohydrates Flashcards

1
Q

Carbohydrates

A

Carbohydrates are among the “macronutrients” that provide substantial metabolic energy.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Phytate

A

Phosphate-containing saccharide found primarily in cereal brans (1% in oat and 3.7% in wheat brans). They substantially bind cations (ex. Zn2+)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Give three examples of disaccharides

A
  1. Lactose 2. Sucrose 3. Lactulose
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Examples of polysaccharides

A
  1. Starches: amylose, amylopectin, glycogen 2. Hemicellulose, cellulose, pectins, and gums
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Lactose

A

ß- 1,4 linked galactose + glucose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Lactose is unique to what?

A
  • Milk, the primary carbohydrate in milk
    • A significant portion of the energy in milk
    • Contributes substantially to osmolarity of milk
    • A poor substrate for pathogenic microbes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is unique about birds regarding lactose?

A

Birds do not digest lactose; they will develop diarrhea when given liquid milk or milk powder containing lactose.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Is lactose readily digestable in adults?

A
  • No, lactose is not readily digested in adults
    • The beta-1,4 linkage in lactose is resistance to hydrolysis by disaccharidases present in adults. Saccharides digested in animals have alpha-1,4 linkages
    • Lactose is cleaved in young animals by transient expression of “lactase”, a disaccharidase specific for lactose
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Lactulose

A
  1. beta-1,4 linked galactose + fructose
  2. Not hydrolyzed by mammalian enzymes
  3. Hydrolyzed by some gastrointestinal microbial enzymes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Sucrose

A
  1. alpha 1,4-linked glucose + fructose
  2. Digested by animals, even cats
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Sucrose - Dogs

A
  1. A positive effect on the acceptability of food
  2. A “humectant” in the manufacture of semi-moist foods (humectant –> keeps food moist)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Sucrose - Cats

A
  1. Indifferent to sucrose and other sweet substances
  2. Causes fructosuria in high dietary concentrations, >15% of diet
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Starch

A
  1. alpha 1,4 and 1,6 linkages of glucose
  2. Straight chains (amylose) or in chains with branches (amylopectin in plants, and glycogen in animals)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q
  • Plant starches occur in….
A
  • Plant starches occur in semicrystalline granules
    • Granules are variably resistant to digestion
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What does high moisture and heat do to the semicrystalline granules of plant starches?

A
  • High moisture and heat (as with cooking of starches in commercial canned and dry expanded diets) “gelatinize” granules
    • Melts and hydrates starch crystals
    • Transforms starch structurally
    • Increases digestibility of starches
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Starch - Glutens

A
  • Proteins that are associated with plant starches include glutens
    • Glutens of low water solubility, amino acids and structure vary
    • Wheat gluten causing food hypersensitivity in rare cases
17
Q

Why are plant starches not well tolerated in neonates?

A

Because neonates lack sufficient amylase activity to readily utilize starch.

18
Q

Cellulose

A

Beta-1,4 linkages of glucose

Straight chains that lie flat, forming layers held together with hydrogen

Structure forms densely packed, water-insoluble material in plant cell wall fibrils

Structure prevents digestion by animals

19
Q

What to gastointestinal microbes do with cellulose?

A
  • They slowly produce organic acids from cellulose
    • Microbes produce beta 1,4 glucosidases which animals lack
    • Organic acids are metabolized by the host
    • Organic acids are a substantial energy source for ruminant and post-gastric fermenters
20
Q

Hemicellulose

A
  • Chemically and structurally different from cellulose
    • A variety of saccharides in polymers that are 50 to 200 units in length with branching (unlike cellulose)
    • Insoluble in water (like cellulose)
    • Structure prevents digestion by animals (like cellulose)
21
Q

Hemicellulose and cellulose - contribution to crude fiber

A
  1. Cellulose contributes greatly to crude fiber in proximate analysis
  2. Hemicellulose only partially contributes to “crude fiber” in proximate analysis because some hemicellulose is soluble in dilute alkaline solution
22
Q

Polysaccharides - Pectins and Gums

A
  1. Structure prevents digestion by animals
  2. Good water solubility
  3. Gastrointestinal microbes produce organic acids from them
  4. Used in commercial pet foods
    • Gelling agents, making gravy, forming “meat-chunks”
23
Q

Dietary Fiber

A

DIetary fiber is structurally diverse, considered to be remnants of edible plant cells

Include polysaccharides, lignin, and other associated substances resistant to digestion by the animal host.

24
Q

Dietary Fiber - Examples of Polysaccharides

A

Cellulose, hemicellulose, pectins and gums

25
Q

Dietary Fiber - Example of non-polysaccharide

A
  • Lignin
    • Polyfunctional phenol polymers infiltrated through the cellulose of plant cells
    • Imparts “woody” quality to plants, greatest in mature plants
    • Water insoluble
    • Cannot be digested by gastrointestinal microbes
26
Q

Properties of dietary fiber

A
  1. Not digestible by the animal host
  2. Variably water soluble
  3. Variably fermentable by gastrointestinal microbes
27
Q

Dietary fiber uses in dogs and cats

A
  1. Lower dietary energy density for weight reduction
  2. Empirical treatment of chronic diarrhea (fermentable fibers)
  3. Increase fecal bulk and moisture content depending on type of fiber
    • Fibers that bind little water increase fecal bulk and tend to harden the feces
    • Fibers that absorb large amounts of water increase fecal bulk and tend to soften the feces and increase fecal water loss
  4. Manage diabetes mellitus - slows gastric emptying and absorption of alimentary carbohydrate
28
Q

Dietary carbohydrates in herbivores - what is nutritionally essential for GI function?

A

Dietary carbohydrate in the form of dietary fiber is nutritionally essential for normal GI function.

29
Q

Dietary carbohydrates in dogs and cats

A
  • Dietary carbohydrate is NOT nutritionally essential, EXCEPT:
    • During pregnancy and lactation when dietary carbohydrate is very low or absent AND dietary protein is marginal
30
Q

Dogs and cats: “low” carbohydrate diets

A
  1. High energy diets, more energy from fat (performance, critical care)
  2. High protein diets, protein exhcanged for carbohydrate (feline diabetes)
31
Q

Dogs and Cats - “high” carbohydrate diets

A
  1. Provide energy in place of fat and/or protein
  2. Useful clinically for weight loss treatment, canine pancreatitis
32
Q

Carbohydrate use in commercial foods for dogs and cats - Dry-type, extruded diets

A
  • Typically contain >30% carbohydrate from starch in grain or potato ingredients
  • Extrusion requires that the dietary ingredients contain sufficient starch to form a gelatinized-dough
  • Carbohydrate is a less expensive source of dietary energy than protein and fat
33
Q

Carbohydrate use in commercial foods for dogs and cats - Semi-moist diets

A
  • Carbohydrates are used as preservatives and humectants in semi-moist foods
34
Q

Carbohydrate use in commercial foods for dogs and cats - Canned Diets

A
  • Carbohydrate content varies markedly, especially dog foods
  • “Meat-type” canned foods may contain very little carbohydrate

Nutrition (13 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions