Carbohydrates Flashcards
(93 cards)
1
Q
Normal level of glucose in blood
A
4-6mmol/L
fasting
2
Q
AI for fiber for men
A
38g/day
3
Q
AI for fiber for women
A
25g/day
4
Q
DV for fiber
A
25g per 2000kcal
5
Q
The pancreas releases __ when there is an increase in blood glucose
A
INSULIN
6
Q
The pancreas releases __ when there is a decrease in blood glucose
A
GLUCAGON
7
Q
Glycemic load
A
glycemic index x grams of carbs
8
Q
Glycemic Index
A
Scale that ranks a carbohydrate-containing food or drink by how much it raises blood sugar levels after it is eaten or drank
9
Q
Glycemic response
A
extent to which a food raises blood glucose concentration and elicits insulin response
10
Q
AMDR for carbs
A
45-65%
= 225g-325g
11
Q
AMDR for fat
A
20-35%
= 44g-78g
12
Q
AMDR for protein
A
10-35%
= 50g-175g
13
Q
RDA of carbs (glucose) needed for brain
A
130g
14
Q
High GI foods
A
processed foods (white bread, ice cream, coke), ready-to-eat cereal (corn flakes)
15
Q
Low GI foods
A
lentils, beens, hummus, peanut, milk products
16
Q
Moderate GI foods
A
whole grain, fruits
17
Q
Main source of carbs
A
plants, thanks to photosynthesis
18
Q
What is the chief source of energy, preferred source for the brain, nerve cells, red blood cells
A
Glucose
19
Q
Monosaccharides
A
- glucose
- fructose
- galactose
20
Q
Which monosaccharide is a pentagone and is the sweetest ?
A
fructose
21
Q
Which monosaccharide is part of every disaccharide?
A
Glucose
22
Q
How are disaccharides formed?
A
Condensation reaction, water is released
23
Q
When and how are disaccharides broken down?
A
During digestion, by hydrolysis
24
Q
Disaccharides
A
- Sucrose (glucose + fructose)
- Maltose (glucose + glucose)
- Lactose (glucose + galactose)
25
Example of maltose, sucrose, lactose
maltose : barley
sucrose : table sugar
lactose : milk
26
Polysaccharides
- Glycogen
- Starch
- Fiber
27
Glycogen
Storage from of glucose in humans
Highly branched
Not in plants
28
Starch
Storage form of glucose in plants
Long, branched and unbranched chains
In grains, legumes, root crops
ex: amylopectin (branched), amylose (unbranched)
29
Fiber
Structural part of plants
Soluble or insoluble
Non digestible
ex: cellulose
30
Calories in fiber
1.5-2.5 kcal/g (avg 2)
31
How come fiber gives us energy ?
Some bacteria in the GI tract ferment fibres
32
Which fiber is in oats, barley, legumes, citrus fruits
SOLUBLE
- viscous
- fermentable
- adds thickness
- gives energy
33
Which fibre is in whole-grain (bran), vegetables
INSOLUBLE
- non viscous
- less fermentable
- touche, stringy, gritty
- doesn't give energy
34
Resistant starch
Starch molecules that resist digestion, functioning like fiber
ex: raw potato, green banana
35
Digestion of starch
mouth - amylase breaks starch to maltose
stomach - amylase inactivated by acids
s intestine & pancreas - pancreatic amylase breakdown starch. On the surface of the small intestine : maltase, sucrase, lactase breakdown disaccharides to monosaccharides, intestinal cells absorb the mono.
36
Digestion of fiber
mouth - moistens fibre
stomach - fibre not digested
s intestine - delays absorption of other nutrients, feeling of satiety
l intestine - bacterial enzymes digest fiber
37
Where does most digestion of carbs occur?
In the small intestine, via pancreatic amylase
38
What is the consequence of bacteria fermenting fiber
causes gas, water, short chain fatty acids to be produced
39
What enters in capillaries in intestinal villi?
Monosaccharides
40
How do monosaccharides travel to liver?
Via portal vein
41
Once in liver, fructose and galactose are converted to
Glucose
42
What enters the intestinal cell via ACTIVE transport?
glucose and galactose
| - FAST (requires energy)
43
What enters the intestinal cell via FACILITATED DIFFUSION?
fructose
| - SLOW, passive
44
What is fibre's role?
Holds water, regulates bowel activity, binds bile, cholesterols and some minerals
45
When is lactase activity highest?
highest : immediately after birth
| It declines with age : 70% population loses the activity
46
Symptoms of lactose intolerance
- bloated
- flatulence
- cramps
- nausea
- diarrhea
47
Causes of intolerance
- age
- medicine
- prolonges diarrhea
- malnutrition
=> cause damage to intestinal vili
48
Lactose intolerance is mostly where?
in Southeast Asians, Aboriginal
| trait has a genetic component
49
Lactose intolerance is an allergy, T/F
F
| = lack of production of lactase on brush border of vili
50
What is an alternative for lactose-intolerant people
- fermented milk products (yoghurt, kefir, cheese)
- lactose -reduced milk
- milk with a meal
- lactase pills (have active bacteria)
51
How much lactose in low fat yoghurt?
15g
| -> lactose content is higher than milk
52
A person has a low tolerance to lactose, would you suggest low fat yoghurt or high fat yoghurt?
high fat yoghurt
53
Which types of fibres do you want?
| Want both types at varying degrees
- insoluble (non-viscous)
cellulose, ligin, hemicellulose, fibrous veg, wheat bran , black beans
- soluble (viscous)
pectins, gums, beans, legumes, nuts, fruits, oats
guar gum, carrageenan
54
Excessive intake of fiber can cause
intestinal discomfort and interfere with mineral absorption
55
adequate fiber intake
lowers blood cholesterol, prevents colon cancer, prevents appendicitis, controls diabetes
56
What is the UL for fiber
none
57
How much fiber does the average canadian consume?
11-16g
58
Actions in the body of soluble fiber and health benefits
actions in body : decrease cholesterol by binding bile, slow glucose absorption, slow transit of food through GI trac, hold moisture, increase satiety
health benefits : lower risk of heart disease, diabetes, help weight management
59
Actions in the body of insoluble fiber and health benefits
actions in body : increase fecal weight
| health benefits : decrease constipation, decrease risk of haemorrhoids, decrease risk of colon cancer
60
Someone wants to increase their satiety and help with their weight management, what should they consume?
barley, oats, oat bran, rue, fruits, legumes, seaweeds, seeds & husk
61
Someone wants to reduce constipation, reduce risk of colon and rectal cancer, what should they consume?
brown rice, fruits, legumes, seeds, wholesaled grain, vegetables
62
What occurs with cholesterol when consume HIGH FIBER diet
more chol is carried out of the body (through bile)
63
What occurs with cholesterol when consume LOW FIBER diet
more chol (from bile) is reabsorbs and returned to bloodstream
64
What organ makes bile?
| What organ stores it?
Liver makes it
| Gallbladder stores it
65
Prune juice contains __ which has a laxative effect
SORBITOL
66
Ketosis
Not enough glucose, breakdown
67
How does glucose function in metabolism ?
```
Is oxidised for energy,
converted to glycogen for energy storage
converted to fat for energy storage
prevents ketosis
precursor for amino acids
```
68
Can glucose reassemble when broken in half? When broken into smaller molecules?
YES
| NO
69
Which organ is the first to respond to blood glucose changes?
Pancreas
70
when INCREASE in blood glucose
pancreas releases INSULIN
71
when DECREASE in blood glucose
pancreas releases GLUCAGON
72
Epinephrine acts like
Glucagon
| - signals liver cells to release glucose in a stress situation
73
Does the brain store glucose?
YES, small amount for emergency
74
Do muscles and liver store glycogen?
YES
- muscles: conserve for own use (2/3)
- liver: is generous with its glycogen (1/3)
75
When there is no carbohydrate, what happens?
Gluconeogenesis : our liver can make glucose from non-carbohydrate carbon substrates (glucogenic amino acids, glycerol, odd-chain fatty acids, pyruvate and lactate.)
76
Which 3 hormones maintain blood glucose constant?
| Released by?
- insulin
- glucagon
(- epinephrine)
by pancreas
77
Insulin
Moves glucose from bloodstream to muscle and fat cells
78
Glucagon
Elicits release of glucose form liver glycogen stores
79
Type 1 diabetes mellitus
- pancreas doesn't produce insulin/very little
- high BG because no insulin to transport it into muscles
- autoimmune
- virus attacked pancreas
Treatment : insulin, diet & exercice
80
Type 2 diabetes mellitus
- more genetic
- can't produce enough insulin or can't properly use insulin
- "insulin resistance" -> high BG
- usually consq of obesity
Treatment : diet+ exercice / with med or insulin
81
Which of type 1 and Type 2 D is most frequent
Type 2 : 90%
| Type 1 : 10%
82
Signs of T1D
- excessive urination & thirst
- glucose in urine
- cravings for sweets
- infections
83
Glycosuria
Too much glucose in blood -> spills in urine
| because kidneys can't cope
84
Is there glucose in urine normally?
NO
| proximal tubule in kidney can resorb a limited amount of glucose from blood to put back into circulation
85
Risks of diabetes
cardiovascular disease, damages organs, blood vessels, nerves, blindness, nerve pain, ulcers
86
How to nutritionally manage diabetes ?
low in saturated fat
balanced meals, 3 a day
adequate protein intake
87
Official DRI for free sugars =
| WHO recommendation =
= no more than 25% total energy intake (=500kcal, 31tsp)
| = less than 10% total energy intake
88
Dental caries
bacteria ferment sugars, produces acid that erodes tooth enamel
food factor associated with tooth decay :
- time in mouth
- sticky foods
- frequency of sugar consumption
89
Artificial sweeteners
= nonnutritive sweetners
- calorie free
- toxic if high doses
ex: saccharin, sucralose, cyclamate, aspartame
90
Sugar acohols
= nutritive sweeteners
- not fermentable
- 2kcal/g
- "sugar-free", "no added sugars"
- laxative effect if high doses
ex: xylitol, mannitol, sorbitol, polydextrose
91
What sugar would you advise to someone who suffers from dental carries?
- artificial sweeteners or sugar alcohols
92
What sugar would you advise to someone who doesn't want calories?
- artificial sweeteners
93
What artificial sweetener can't be consumed by people with phenylketonuria?
aspartame
