NFS284 Carb 2 Flashcards
Carbohydrate metabolism - CHO for energy - Regulation of blood glucose - Abnormal blood glucose
1
Q
How is glucose metabolized?
A
Cellular respiration / aerobic metabolism
2
Q
How much energy is made per glucose?
A
38
3
Q
What process is used to generate energy?
A
Cellular respiration / aerobic metabolism
4
Q
1g carbs contains _ kcal
A
4
5
Q
What cells can only use glucose for energy?
A
- RBC
- Brain cells
6
Q
What supplies energy for daily activities (normally)?
A
Carbs & fats
7
Q
Glucose is especially important for energy during…
A
intense exercise
8
Q
Why is CHO needed for intense exercise?
A
During intense exercise, O is limiting factor
CHO deliver more ATP per O than fat
9
Q
4 steps of cellular respiration
A
- glycolysis
- Acetyl-CoA formation
- citric acid cycle
- electron transport chain
10
Q
Glycolysis
A
Breaks glucose (6C) -> 2 pyruvate (3C units)
11
Q
When there is no O, what is the pathway used to make ATP?
A
- Glycolysis
2. Pyruvate becomes lactate
12
Q
Lactic acid inhibits…
A
glycoloysis
13
Q
If there is excess rate of electrons going to the electron transport chain…
A
Will form oxygen radicals -> oxidative stress
14
Q
What is the anaerobic part of metabolism?
A
Glycolysis
15
Q
What is the aerobic part of metabolism?
A
Acetyl-CoA formation
citric acid cycle
electron transport chain
16
Q
Gluconeogenesis
A
Make glucose from proteins
17
Q
FA can be made in the body by…
A
Proteins
18
Q
Excess proteins are…
A
made into glucose or fat (gluconeogenesis)
19
Q
Blood glucose is regulated by…
A
Liver
Hormones secreted from pancreas
20
Q
Antagonistic to insulin
A
glucagon
21
Q
insulin produced by…
A
beta cells of pancreas
22
Q
Insulin stimulates…
A
- uptake of glucose by liver and muscle
- storage of glucose as glycogen in liver and muscle
23
Q
What are the 2 types of glucose transporters?
A
- GLUT2
2. GLUT4
24
Q
GLUT2 transporter
A
Sits on cell membrane that slowly transport glucose into cell. Act as sensors of glucose levels.
Does not require insulin
25
GLUT4 transporter
Insulin signal causes them to TRANSLOCATE to cell membrane from the cytoplasm. Fast transport of glucose.
Will be removed once insulin signal is gone.
26
Glucagon is produced by...
alpha cells of the pancreas
27
Glucagon stimulates...
- breakdown of glycogen -> glucose
| - gluconeogenesis
28
Describe blood glucose after consuming 80g of glucose.
1. Blood glucose spikes
2. Insulin secreted and lowers blood glucose
3. Insulin causes blood glucose to be lower than normal
4. Stimulates glucagon release
5. Glucagon returns blood glucose levels back to normal
29
Fuel use: fasting
- High glucagon (glucose level maintained by gluconeogenesis & glycogen breakdown)
- Fat cell secrete FFA for use by muscle
- FFA inhibit glucose use (try to keep blood glucose high)
30
Fuel use: post-prandial
Insulin
1. Stops fat use
2. GLUT4 transporter
3. Store/use glucose in adipose tissue & muscles
4. Stop gluconeogenesis
5. Promote glycogen formation
31
2 routes of FA metabolism
1. When CHO is available
| 2. When CHO is not
32
FA metabolism when CHO is available
1. FFA -> acetyl coa
2. citric acid cycle
3. electron transport chain
33
FA metabolism when CHO is not available
1. FFA -> acetyl coa
| 2. ketones
34
Ketones are...
- Used for energy (brain)
- Excreted in urine
- Accumulates in blood
35
When are ketones produced?
- Fasting / low glucose
| - Insulin levels low enough
36
Where are ketones produced
In liver: FFA -> ketones
37
Where does gluconeogenesis happen?
liver
38
Symptoms of hypoglycaemia
- irritability
- nervousness
- sweating
- anxiety, shakiness, rapid heart beat
- hunger
- weakness
- headache
- seizure, coma (overdose insulin)
39
Diagnosis of hypoglycaemia
- Display symptoms of hypoglycaemia AND
| - Low blood glucose
40
Types of hypoglycaemia
1. Too much insulin (diabetes treatment)
2. Reactive hypoglycaemia
3. Fasting hypoglycaemia
41
What is reactive hypoglycaemia?
When consuming CHO, insulin causes bld glucose to fall below normal
42
What might cause reactive hypoglycaemia?
high insulin secretion
| gastric emptying
43
Treatment for reactive hypoglycaemia
small frequent meals
low sugars
high protein/fibre
44
Cause of fasting hypoglycaemia
insulin secreting tumour
45
What is the most common type of hypoglycaemia?
fasting hypoglycaemia
46
What is fasting hypoglycaemia?
Having low blood sugar in the fasting state
47
Symptoms of diabetes
- excessive thirst
- frequent urination
- glucose in urine
- blurred vision
- frequent infections
- poor wound healing
- weight loss
- pain/numbness in feet & legs
48
Why is there glucose in the urine for diabetic people?
Kidney usually filters glucose from urine, but due to excessive glucose, kidney's load is exceeded
49
Type I diabetes
B cells destroyed by auto-immune process; insulin not secreted
50
Types of diabetes
1. type I
2. type II
3. gestational diabetes
51
Gestational diabetes
Pregnancy causes stress on B cells -> decreased insulin secretion.
High blood glucose due to pregnancy.
52
There are cutpoints for blood glucose. What are they based on?
Eat glucose -> measure blood glucose.
| Certain marks indicate if normal, pre-diabetes, or diabetes.
53
Diabetes is diagnosed by...
high blood glucose
54
Diabetic retinopathy
Hemorrhages & aneurysms inside eye may cause blood clots. Blood clot lower O getting to eye. Eye will form more vessels to supply O, but those vessels are weak and break easily -> lead to blindness
55
2 categories of diabetic retinopathy
1. non-proliferative
| 2. proliferative
56
Difference between non-proliferative & proliferative
Growth of abnormal blood vessels are only present in proliferative
57
Treatment for retinopathy?
Laser: kills weak blood vessels
58
Leading cause of blindness?
Diabetes
59
Leading cause for kidney failure
diabetes
60
Complications of diabetes
1. Micro-vascular diseases
Retinopathy
Nephropathy
Neuropathy (pain & numbness at extremities)
```
2. Macro-vascular disease
MI
Stroke
Poor circulation in feet and legs (amputation)
Increased infections (poor blood flow)
```
61
Diabetes is related to what other health risk?
Obesity
62
Trend of number of people with diabetes?
Increasing instances of diabetes
| Rate of increase is faster than expected
63
Is control of blood glucose necessary for type I diabetes?
Yes: controlling blood glucose reduces diabetes complications
64
Treatment for type I diabetes
Intensive insulin therapy
| Balance diet, exercise, insulin injections
65
Intensive insulin therapy
3-4 insulin injections per day OR insulin pump
| combine short & long acting insulins
66
Insulin dose for type I diabetes is based on...
CHO consummed
| Blood glucose monitors (checked 3-4 times per day)
67
Usually, who gets type II diabetes?
- Older people
- Obese people
- Obese children
68
Ability of glucose to stimulate insulin is dependent on...
B cell function
69
Ability of insulin to reduce glucose is dependent on...
insulin sensitivity
70
Insulin sensitivity is dependent on...
genetics
| obesity
71
B cell function is dependent on...
Genetics
| Obesity
72
Good diet and exercise cause ___ insulin sensitivity and __ insulin secretion
Better
| Lower
73
Pregnancy cause insulin sensitivity to go...
| and insulin secretion to go...
down
| up
74
When does pregnancy make mothers diabetic?
When she can't secrete more insulin to compensate for the lack of sensitivity (maybe genetics)
75
What will gestational diabetes predisposition you towards?
Higher risk for getting diabetes in the future
76
What causes insulin resistance during pregnancy?
placental hormones
77
Prevalence of gestational diabetes
Lower in non-Aboriginals
| Higher in Aboriginals
78
Complications due to gestational diabetes for mother
C-section
Pre-eclampsia
Birth trauma
Diabetes after pregnancy
79
Complications due to gestational diabetes for infants
```
Stillbirth
Birth defects
Macrosomia
Shoulder dystocia
Diabetes
```
80
Pre-eclampsia
High BP
| High protein in urine
81
Macrosomia
Really heavy/big baby
82
shoulder dystocia
head of baby can come out, but shoulder is stuck
83
How to control complications of gestational diabetes?
- Treatment with insulin
- Diet, exercise
- Examination of eyes, kidney, feet
84
GDM treatment reduce risk for complications by...
- Control blood glucose, lipids, BP
| - Manage body weight
85
Is there a diabetic diet?
No, just a normal "healthy" diet
86
What has the Canadian diabetes association developed to help diabetics eat healthy?
Just the Basics
| Beyond the Basics
87
Just the Basics
simplified dietary plant:
- use plate model to control portions
- Limit simple sugars
- More starch foods
- Glass of milk & fruit every meal
- Limit alcohol
88
Plate model
1/2 vegetables
1/4 grains & starches
1/4 meat & alternatives
89
Beyond the Basics
Foods divided into groups by CHO content by dietician.
| Specific recommendations of how much CHO is consummed through fruits, meats, milk...etc.
90
RDA for CHO
130g/day (amount brain uses)
| Minimum amount
91
AMDR for CHO
45-65%
92
No more than __% of CHO consumed should be from refined sugars
25
