Unit 6 - Carb structure and measurement Flashcards
1
Q
What is the basic composition of all carbohydrates
A
Cn(H2O)n
1
Q
What are carbohydrates made up of
A
Carbon and Water
(C,H,O)
2
Q
Composition of Glucose
A
6 Carbons
6 Waters (H2O)
3
Q
What is the molecular weight of 1 Carbon
A
12 g/mol
4
Q
What is the molecular weight of 1 Water (H2O)
A
18 g/mol
5
Q
Monosaccharide
A
One sugar
6
Q
Disaccharide
A
Two sugars linked together
7
Q
Polysaccharide
A
Multiple sugars linked together
8
Q
What determines if a sugar is a reducing sugar
A
If it can form an aldehyde group
9
Q
Reducing sugars are capable of what action?
A
Reducing cupric ions into cuprous ions
10
Q
What sugars are monosaccharides?
A
Fructose
Glucose
Galactose
11
Q
What sugars are disaccharides?
A
Sucrose
Maltose
Lactose
12
Q
What sugars are NOT reducing sugars?
A
Sucrose
13
Q
What sugars are reducing sugars
A
Glucose
Galactose
Maltose
Fructose
Lactose
14
Q
What is maltose composed of?
A
Two glucose linked together
15
Q
What is galactose made up of
A
6 Carbons
6 H2O
16
Q
What is different between glucose and galactose?
A
OH-H flipped
17
Q
What is lactose made up of
A
1 galactose
1 glucose
18
Q
What is different about fructose
A
Location of C=O on the second carbon makes the structure look different
19
Q
What is sucrose made up of
A
Glucose and fructose
20
Q
Storage form of carbs in animals
A
Glycogen
21
Q
What is glycogen made up of
A
Glucose polysaccharide
22
Q
What is the storage carb in plants
A
Starch
23
Q
What is starch made up of
A
Glucose polysaccharide
24
How is glucose broken down for energy production?
Broken down into CO2 and H2O
25
Clinitest reacts with reducing sugars such as
Fructose
Glucose
Galactose
26
What energy processes is glucose used in?
Anaerobic glycolysis
Aerobic Krebs cycle
Aerobic oxidative phosphorylation
27
Where is glucose stored in
Liver - Glycogen
Adipose tissue/Fat - Triglycerides
28
What can glucose be converted into? (noncarbohydrates)
Ketoacids
Amino acids
Protein
29
What is the carbohydrate nutrition process?
Food
Salivary amylase breaks disaccharides and polysaccharides
Pancreatic amylase continues breakdown in small intestine
Monosaccharides absorbed by small intestines
Monosaccharides transported to liver via hepatic portal vein
Liver converts non glucose monosaccharides into glucose
30
What structure transports monosaccharides to the liver
Hepatic portal vein
31
What is glucogenesis
When the liver converts non-glucose monosaccharides into glucose
32
What is the only monosaccharide that can be used for ATP production?
Glucose
33
Glycogenesis
Liver converting glucose into glycogen for storage
34
Glycogenolysis
Breakdown of glycogen into glucose for energy
35
If oxygen is low in the tissues and glucose is used, what happens?
Glucose used anaerobically, lactic acid builds up
36
Gluconeogenesis
Glucose made from non-carbohydrate sources
37
What does your body do if there is not enough glucose?
Gluconeogenesis
38
Where does your body grab from to produce glucose?
Lipids
Amino acids
Glycerol
Lactate
39
Why is the conversion of non-carbohydrate sources not preferred?
Byproducts like ketoacids are produced, can be dangerous
40
Lipogenesis
Production of fat with excess glucose
41
Where is insulin produced
Beta islets of langerhans in pancreas
42
What does insulin want to do?
Lower blood glucose
43
How does insulin lower blood glucose
Increase tissue cell uptake
Glycogenesis
Prevent breakdown of glycogen
Lipogenesis
Suppress glucagon release
Promote formation of proteins
44
What is insulin formed from?
Proinsulin
45
What does proinsulin do
Break down into insulin and C-peptide
46
Where is glucagon produced
Alpha islets of langerhans
47
What does glucagon want to do
Increase blood glucose
48
How does glucagon increase blood glucose
Glycogenolysis
Lipgenolysis
Gluconeogenesis
49
Where does Cortisol come from
Adrenal glands, adrenal cortex
50
What does cortisol do
Stimulate gluconeogenesis
51
What does cortisol want to do
Increase blood glucose
52
Cushings Syndrome
Increased cortisol
Hyperglycemia
53
Addisons Disease
Low cortisol
Hypoglycemia
54
Where is epinephrine produced
Adrenal medulla
55
When is epinephrine produced
Stress or fright
56
What does epinephrine want to do
Increase blood glucose
57
How does epinephrine increase blood glucose
Inhibit insulin
Produce glucagon
Stimulate glycogenolysis
58
What do thyroid hormones do
Regulate body metabolism
Increase blood glucose
59
How do thyroid hormones increase blood glucose
Increase glucose absorption in GI
Stimulate glycogenolysis
Break down insulin
60
Where is growth hormone produced
Anterior pituitary
61
What does growth hormone do
Growth
Increase blood glucose
62
How does growth hormone increase glucose
Inhibiting glycolysis
Antagonizing insulin
63
What does an overproduction of GH cause
pituitary gigantism
Acromegaly
64
What hormones raise blood glucose
Glucagon
Cortisol
Epinephrine
Thyroid Hormones
Growth Hormone
65
Glycolysis
Glucose oxydation
66
Krebs cycle
Citric acid cycle
67
ATP
Oxidative phosphorylation
68
Glucose metabolism forms..?
ATP
Carbon Dioxide
Water
69
What anticoags are used for glucose analysis
NaF
Lithium heparin
70
When using CSF to measure glucose, what needs to be done?
Centrifuge and assay supernatant only
71
When should CSF be analyzed for glucose levels?
Immediately
72
What can signify there's something wrong when analyzing CSF glucose levels?
False decrease - WBC and Bacteria consume glucose
73
Preferred blood glucose measurement method?
Fasting
74
Fasting
Specimen collected after 8 hours no food, drink besides water
75
Normal fasting glucose levels
74-99 mg/dL
76
What can emotional disturbances do to blood glucose levels?
Falsely elevate because of cortisol and epinepherine
77
How long do you have to wait for a postprandial glucose test?
Two hours
Taken after a high carb meal
78
Time limit for removal of glucose from cells
2 hours, ideally ASAP
79
What tube is ideal for glucose testing only?
NaF because it inhibits other analytes
80
How long does NaF preserve blood for glucose testing at RT?
24 hours
81
How long does NaF preserve blood glucose for testing in the refrigerator?
48 hours
82
How much do glucose levels go down per hr if NOT separated?
5-7% per hour
83
How long are separated specimens stable at RT for?
8 hours
84
How long are separated specimens stable for in the refrigerator?
3 days
85
What can affect glucose drop/usage?
High hematocrit in storage
Neonate blood has high hct
86
What percent of glucose is in CSF
60% of plasma glucose
87
What can happen if testing on CSF is delayed?
WBC and Bacteria cause extremely low decrease
88
How do children and infant levels of glucose differ from adults?
Lower than adults
89
Arterial & Capillary vs Venous glucose levels
Arterial about 2-5 mg/dL higher than venous but 20-70 mg/dL higher in non fasting people
90
WB glucose levels vs venous
~10-15% lower in WB than plasma or serum
Bcz of dilution effect
91
High hematocrit results in _ glucose values
Lower
92
Low hct results in _ glucose levels
Higher
93
A whole blood glucometer is being used to evaluate a critically ill patients glucose. Is this okay?
No, abnormal hct, pH, and maltose can alter glucose readings
94
IFCC recommends standardizing adjustment levels for WB to Plasma by what %?
11%
95
Formula for WB glucose value to serum or plasma glucose value
WB glucose x 1.11 = Serum/Plasma glucose
96
Formula for serum/plasma glucose value to WB value
Serum/Plasma glucose x 0.9 = WB glucose
or
Serum/Plasma glucose/1.11 = WB glucose
97
What is the renal threshold for glucose
160-180 mg/dL in blood
98
What is renal glycosuria
Low renal threshold because PCT isn't as efficient
99
A person eats a meal and then urine is tested for glucose levels. What should that look like?
Little to no glucose should be present in the urine
100
What is the downfall of clinitest or copper reductase?
Not specific for glucose
Many interferences
101
Current enzymatic glucose measurement methods
Hexokinase
Glucose Oxidase
102
Hexokinase reaction
Glucose + ATP < Hexokinase + Mg > Glucose-6-PO4 + ADP
Glucose-6-PO4 + NADP 6phosphogluconate + NADPH + H
103
What are the two detection methods for glucose using Hexokinase?
Absorbance of NADPH measured at 340 nm
or
NADPH detected using tetrazolium
104
Glucose oxidase reaction
Glucose + 2 H2O + O2 Gluconic acid + 2 H2O2
105
Two detection methods using glucose oxidase
Chromogen to detect peroxide production
or
Consumption of oxygen using oxygen electrode or production of peroxide using electrode
106
What enzyme is required for glucose oxidase method?
Mutarotase to convert alpha-D glucose to beta-D glucose
107
What form of glucose is required for glucose oxidase?
Beta - D glucose
108
Copper reduction method formula
Cu + Glucose --> Cu2O (red) + CuOH (yellow)
109
Cupric
Cu2+
110
Cuprous
Cu+
111
What color is cuprous ion
Red
112
What reducing sugars are detected by clinitest
Glucose
Galactose
Lactose
Fructose
113
What reducing agent interferes with clinitest/copper reductase
ascorbic acid or vitamin C
114
Newborn screening for inborn errors of metabolism of glucose
Copper reductase for Galactose
Replaced by HPLC Tandem MS
115
Glycated hemoglobin
Glucose rects with a.a. of proteins
116
What does glycation do to tissues?
Damage
117
How does glucose bind to amino group?
In its aldehyde form
118
Is the attachment of glucose to an a.a. enzymatic or non enzymatic?
Non-enzymatic
119
Is the attachment of glucose to an a.a. reversible or irreversible?
Irreversible
120
What factors dictate glycated hgb levels?
Plasma glucose
Lifespan of RBC
121
What specimen is used for Glycated hgb?
EDTA with no fasting
122
How long is specimen for glycated hgb stable for?
4C for 1 week
123
HbA1c reflects average blood glucose over how long?
8-12 weeks
124
Normal adult glycated hgb
A1
125
Normal adult nonglycated Hgb
A0
126
Where does hgbA1c attach on hb?
Amino terminus of the beta chain of hgb
127
Most abundant glycated hgb?
A1c
85%
128
What % of all hgb is A1c?
4-6%
129
Different methods of detecting A1c
Bond between glucose and amino group (done w/ ab, chemical affinity)
Charge difference (Ion exchange chromatography, HPLC)
Enzymatically split glycated portion off and measure it
130
If A1c is <4% or >15%, what should you suspect?
Variant hgb
131
Populations with higher prevalence of hgbopathies have a higher prevalence of...?
Diabetes
132
Short RBC life span or young cells result in ___ Ghgb
False decrease
133
How does iron deficiency anemia affect glycation?
Enhanced glycation from metabolic alteration or smaller cells
134
Iron deficiency anemia causes a false ___ in Hgb A1c levels
Increase
135
When can you use A1c measurements in iron deficiency anemia?
Not until anemia is gone
136
How do transfusion affect A1c levels in high A1c levels?
False decrease
137
how do transfusions affect A1c in low A1c?
False increase, because have been sitting in glucose
138
How does renal insufficiency affect Ghgb?
False decrease because high urea attaches to hgb, EPO produces young cells
139
What can cause true hypoglycemia?
Overuse of diabetes medicaiton
Extreme diet
Liver failure
140
What causes a false hypoglycemia?
Renal insufficiency
141
