Unit 12 Flashcards
Useful facts about sugars, starches and fibres (80 cards)
1
Q
What are the 2 major classes of carbohydrates?
A
- simple
- complex
2
Q
What do simple sugars refer to?
A
monosaccharides and/or disaccharides
3
Q
What are examples of monosaccharides?
A
- glucose (blood sugar and dextrose)
- fructose (fruit sugar)
- galactose
4
Q
What is the most abundant and nutritionally relevant monosaccharide?
A
glucose
5
Q
What type of simple sugar is absorbed into the bloodstrem?
A
monosaccharides
6
Q
What is a disaccharide?
A
2 monosaccharides joined by a covalent bond
7
Q
What is the health risk of simple carbohydrates?
A
they are rapidly absorbed into the bloodstream, increased insulin resistance and inflammation
8
Q
What are the disaccharides?
A
- lactose
- maltose
- sucrose
9
Q
What is sucrose made up of?
A
glucose + fructose
10
Q
What is the most widely used natural sweetner? Where does it come from?
A
Sucrose
Can be cane sugar or beet sugar
11
Q
What is maltose formed from?
A
The partial breakdown of starch
12
Q
What makes up maltose?
What 2 monosaccharides?
A
glucose + glucose
13
Q
What makes up lactose?
What 2 monosaccharides?
A
gluctose + galactose
14
Q
What is one of the only animal sugars besides glucose?
A
Lactose
15
Q
What are the 2 complex carbohydrates?
A
- oligosaccharides
- polysaccharides
15
Q
What complex carbohydrates are usually 3 monosaccharide units?
A
oligosaccharides
16
Q
Can the bonds that join the monosaccharides and make up oligosaccharides be broken by human enzymes?
A
No
17
Q
T/F: oligosaccharides are a fibre source
A
true
18
Q
Where do find oligosaccharides?
What foods, kind of?
A
- garlic
- onions
- inulin
19
Q
What are long chains of monosaccharides called?
up to 1000s
A
polysaccharides
20
Q
What are the 3 primary nutritional polysaccharides?
A
- glycogen
- starch
- cellulose
21
Q
In what foods do we find polysaccharides?
A
- potato
- rice
- pasta
- corn
- cereal
- bread
- apple peel
- seeds
- nuts
22
Q
What is energy storage in plants? Is it digestible?
A
starch, is digestible
23
Q
What is energy storage in animals? Is it digestible?
A
glycogen, is digestible
24
What does cellulose do? Is it digestible?
Provides structure in plants, not digestible
25
What are the bonds found in polysaccharides that **can** be broken down by human enzymes? Where are they found?
Alpha glycosidic bonds
found in starch and glycogen
26
What are the bonds found in polysaccharides that **cannot** be broken down by human enzymes? Where are they found?
beta glycosidic bonds
found in cellulose
27
What happens to fiber in the colon?
bacterial enzymes break down fiber to form short chain fatty acids and gas as a byproduct
28
What does fiber feed?
Our gut microbiota
29
What are some brain diseases related to the microbiota?
- anxiety
- depression
- autism
- parkinsons
30
What are some metabolism diseases related to the microbiota?
- obesity
- type 2 diabetes
- fatty liver disease
31
What are some intestinal diseases related to the microbiota?
- Crohns disease
- ulcerative collitis
- irritable bowl syndrome
32
What are pathogen is related to the microbiota?
clostridium diffical infection (C. diff)
33
What is primarly found in the endosperm?
Starch (storage form of glucose in plants)
34
What part of the grain is removed in the refining process making white flour?
the bran and the germ
35
What layer of a grain of wheat is a rich source of dietary fiber?
outer bran
36
What does the germ contain?
- unsaturated fats
- thiamin
- niacin
- iron
- riboflavin
37
Where is soluble fibre found?
- oats
- barley
- psyllium
38
Why is soluble fiber good?
| What does it do
slows down glucose absorption therby lowering blood glucose levels
reduces fat and cholesterol absorptio
39
Does soluble fiber have lower or high calories than digestible carbohydrates?
lower
40
What is the typical calorie range fro soluble fibres?
1-2 kcal/g
41
Where can we find psyllium?
All-Bran buds
42
What is insoluble fibre found in?
- wheat bran
- seeds
- nuts
43
Why is insoluble fibre good?
| What does it do
- moves bulk through gut
- controls gut pH
- removes toxic waste
- prevents constipation
44
What has the biggest impact on blood glucose? What has the smallest?
Biggest: Carbohydrate
Middle: Protein
Smallest: fat
45
How does the body manage glucose?
| Outline the steps
1. blood glucose rises when you eat
2. stimulates pancreas to realease insulin
3. insulin stimulates uptake of glucose into cells and storage as glycogen in liver and muscles. also helps convert excess glucose into fat stores
4. as body uses glucose, blood levels decline
5. stimulates pancrease to release glucagon
6. glucagon stimulates liver cells to break down glycogen and release glucose
7. blood glucose begins to rise
46
Do nutrition labesl distinguish between natural sugars and added sugars?
No
| They only contain info on total sugars per serving
47
Do added sugars add nutrients?
no, only calories
48
What are some negative effects of sugar?
- tooth decay
- empty calories
- often mixed with fats
49
What are non-nutritive sweetners?
Zero-calorie or low-calorie sweetners that are either artificially synthesized or naturally derived
50
What are the sugar intake recommendations for women, men and children?
| Calories + amount of sugar in grams
Women: 100 calories, **24 grams**
Men: 150 calores, **36 grams**
Children: less than 24 grams per day, sugary bevergaes no more than **8 ounces a week**
51
What % of total calories should come from added sugars?
10%
52
What are the alcohol sugars?
- xylitol
- mannitol
- sorbitol
53
How many calories come from alcohol sugars?
2.6 kcal/g
54
What are alcohol sugars most often found in?
gum and candies
55
What is sometimes used to mask the unpleasant taste of artifical sweetners?
alcohol sugars
56
Are alcohol sugars well absorbed in the gut?
No, large amounts can cause diarrhea
57
Where does stevia come from?
Comes from a plant
58
What is aspartame made up of?
2 a.a - aspartic acid + phenylalanine
59
What is released in the digestion of aspartame?
methanol (10%)
aspartic acid (40%)
phenylalanine (50%)
60
How much sweeter is aspartame than sucrose?
200x
61
Is aspartame compatible with high temperatures?
No (>30 degrees celsius)
62
what is the acceptable daily intake for aspartame?
40mg/kg BW
63
64
What are 2 name brand of aspartame?
'Equal' and 'Nutrasweet'
65
How is sucralose made?
chlorinated sugar
66
What is 600x sweeter than sugar?
sucralose
67
What artifical sweetner is splenda?
sucralose
68
Is sucralose safe whent heated?
Yes
69
Is acesulfame K stable at high temps?
Yes
70
Where is acesulfame K often used?
in combination with other sweetners
71
What artifical sweetner is 300x sweeter than sucrose?
saccharin
72
Does saccharin cause bladder cancer?
No, it does in rats but human do not have the same mechanisms
73
How was saccharin discovered?
By accident by a chemist working on coal tar derivatives
74
What does WHO suggest in terms of non-sugar sweetners?
that they not be used as a means of acheiving weight control or reducing risk of concommunicable disease (obesity, type II diabetes)
| may cause insulin resistance
75
What is the mechanism of tooth decay due to sugar?
sugar ffeds bacteria, bacteria produces acid, acid decays teeth
bacteria forms plaque
76
What are the promoters of tooth decay due to sugar?
- increased frequency of stickey foods
- acidic beverages
- excessive cleaning/polishing
- nursing bottle syndrome (babies being put to sleep with a bottle)
77
What are protective foods against tooth decay?
- cheese (increases pH of plaque - decreased acidity)
- protein (with calcium it strenthens enamel)
- low calories sweetners such as sorbitol, mannitol and xylitol (stimulate saliva)
78
What does fluoride do?
Promote remineralization of eroded enamel
79
What does excess fluoride lead to?
fluorosis or mottled enamel during tooth development (cosmetic condition onlyseen in children who are 8 or younger when permanent teeth are developing)
