cc1 CARBO LAB MIDTERM WEEK2 Flashcards
1
Q
- Major food and energy source of the body
- The most abundant biomolecules on earth
- Major constituents of physiologic systems
A
Glycans
2
Q
- Are needed for specific cellular functions
- Are hydrophilic molecules
A
Carbohydrate
3
Q
- Most carbohydrates have the general
formula of
A
(CH2O)
4
Q
-If the carbonyl group is located at one end of the sugar
-it forms an aldehyde group and is known as an
A
Aldose
4
Q
aldoses are reducing
compounds, and are sometimes known as
A
reducing sugars
5
Q
If the carbonyl group is located at an
internal position, the sugar is a
A
ketose
5
Q
Sugar based on number of carbon
A
● Trioses
● Tetroses
● Pentoses
● Hexoses
● Heptoses
● Nonoses
5
Q
This allows for various spatial arrangements around each asymmetric carbon forming molecules
A
stereoisomers
6
Q
Sugars are called _________- which is
derived from the greek word __________
A
-Saccharide
-Sakcharon
7
Q
- Simple sugars, consist of a single polyhydroxy aldehyde or ketone unit
- Most have a sweet taste
- freely soluble in water but insoluble in
non-polar solvents - Composed of backbone of several carbon
atoms
A
Monosaccharides
8
Q
- Two monosaccharides joined covalently by
an O-glycosidic bond - Serves primarily as readily available
energy stores
A
Disaccharides
9
Q
- Sugars linked to form small chains of about 3-10 sugar units/residues
- Most are not digested by human enzymes
-can play an informational role
A
Oligosaccharides
10
Q
-polymer of sugar units joined by glycosidic bonds
-Most carbohydrates found in nature
-Serve as storage carbohydrates or
provides structural support
A
Polysaccharide
11
Q
Upon hydrolysis, polysaccharides
will yield more than
A
10 monosaccharides
12
Q
- The main storage polysaccharide of animal cells - “animal starch”
- A branched polymer containing only one
type of monomer
A
Glycogen
12
Q
Bank of surplus of energy in plants
A
Starch
12
Q
A homopolymer of glucose forming an
alpha-glycosidic chain called
A
Glucosan or Glucan
12
Q
2 types of Polysaccharide
A
● Homopolysaccharide
● Heteropolysaccharide
13
Q
- fibrous, tough, water-insoluble substance found in the cell walls of plants
- also included in diet but cannot be digested
A
Cellulose
14
Q
centered on the provision & fate of glucose
A
Carbohydrate metabolism
15
Q
almost identical to salivary but several times powerful
A
alpha-amylase
15
Q
The most abundant of the absorbed monosaccharides
A
glucose
16
Q
3 major sources of carbohydrates exist in normal human diet
A
● Sucrose
● Lactose
● Starch
17
Q
an enzymes hydrolyzes disaccharides and small glucose polymers into monosaccharides
A
Intestinal epithelial cell
18
Glucose is transported by a ______ mechanism
Sodium Cotransporter
19
- Sodium combines with a transporter protein
- will not transport the sodium to the interior of the cell
SGLT2
19
involved in controlling the blood glucose concentrations within a
narrow range
- liver
- pancreas
-endocrine glands
20
Control of blood glucose is under two major hormones
-Insulin
-Glucagon Control
21
reflects a balance between energy intake from ingested food, hepatic glucose production, and peripheral tissue glucose uptake and utilization
Glucose homeostasis
22
- an exocrine and endocrine gland that controls the regulation of sugar
Pancreas
22
what cell produces insulin
B- cell
23
what cells produces Glucagon
Α-cells
24
in what year insulin was discover
1921-1922
24
- the primary and only hormone responsible for the entry of glucose into the cell
- responsible for increasing glucose levels
hypoglycemic agent
25
Who discovered insulin
-Frederick Banting
-Charles Best
-John Macleod
26
- anabolic and peptide hormone with a
MW of
5800 Daltons
27
Insulin stimulates:
● Glucose uptake
● Formation of glycogen
● Inhibits glucose production
● Increase protein and Triglyceride production
● Promote uptake of ions
28
Glucose is taken up by the Beta-cells via
GLUT2
29
Glucose is then phosphorylated by
glucokinase
30
- enter the cell and activates the Ca2+-dependent proteins
Calcium ions
31
3 Main targets of Insulin:
-liver
-adipose tissue
-muscles
32
-main target in the fasting state
-insulin stimulates glycolysis and glycogenesis, and lipogenesis
-Suppresses lipolysis and gluconeogenesis
Liver
33
- Insulin stimulates triglyceride synthesis
from glycerol-3-phosphate
Adipose tissue
34
- Stimulates glucose transport, glucose metabolism, and glycogenesis
- Increases cellular uptake of amino acids and stimulates protein synthesis
Muscle
35
- Synthesized by Pancreatic Alpha cells
- With a short half-life of about 5 minutes
hyperglycemic agent
35
hormones that increases glucose:
- Cortisol
- Catecholamines
- Growth hormone
- Thyroid hormone
- Adrenocorticotropic hormone
- Somatostatin
36
hypoglycemic agent hormone that stimulates:
1. Glucose production
2. Regulator of hepatic glycogenolysis,
gluconeogenesis, Ketogenesis, Hepatic
amino acid turn over
37
Glucose Uptake:
-GLUT1
-GLUT2
-GLUT3
-GLUT4
-GLUT5
37
glucose transporter for RBCs
-GLUT1
38
- Major glucose transporter in B-cells of pancreatic islets and hepatocytes
- “Glucose sensing”
-GLUT2
38
- Glucose transporter of the brain
- With high concentrations in the hypothalamus, hippocampus, and cortex
-GLUT3
39
- main glucose transporter in the
cells of skeletal muscles, cardiac muscles,
adipose tissue
-GLUT4
40
- for absorption of fructose, found
in the small intestine
-GLUT5
41
-most commonly
encountered hyperglycemia
-most common set of disorders of
carbohydrate metabolism
Diabetes Mellitus
41
There is an increased blood glucose
Hyperglycemia
42
- “Juvenile-onset Diabetes”,
Insulin-dependent diabetes mellitus”
- Represents 5-10% of all cases of diabetes
-Common in the young people ( 9-14 yrs old)
-Due to an Autoimmune destruction of
insulin-producing beta cells in the islets of
langerhans
Type 1 Diabetes Mellitus
42
DM can be due to:
● Defect in insulin secretion
● Defect in insulin action
● Increased glucose production
43
which kills islet cells
CD8+ cytotoxic
T-lymphocytes
44
which induce
destructive inflammation
CD4+ T-cells
45
Pancreatic islets lymphocyte infiltration is termed
Insulitis
46
the following markers are
found in 85-90% of individuals with fasting
hyperglycemia:
● Islet cell autoantibodies
● Insulin autoantibodies
● Glutamic acid decarboxylase
autoantibodies
● Tyrosine phosphatase IA-2 and
IA-2B autoantibodies
● Zinc transporter 8
47
- due to an individual’s resistance to insulin
- Most common type of diabetes (common
in elders ages 40 above)
- Not an autoimmune disease
- glucose tolerance remains near-normal, despite insulin resistance
Type 2 Diabetes Mellitus
48
- the following are the risk factors of type 2 DM:
● Overweight or obesity
● Lifestyle factors
● First-degree relative with diabetes
● Advance age
● High risk ethnicity
● History of GDM
● Hypertension
● Vascular disease & dyslipidemia
● Prediabetes
49
- not an absolute deficiency
- Intensifies DM type 2
Relative Insulin Deficiency
50
Hyperglycemia is toxic to beta-cell function and further impairs insulin
secretion
Glucose Toxicity
51
Complications of diabetes can be divided into:
-Vascular
-Non-vascular
52
Non-vascular:
1. Infections
2. Skin changes
3. Hearing loss
53
Vascular:
1. Microvascular
- Retinopathy
- Neuropathy
- Nephropathy
2. Macrovascular
- Coronary Heart Disease
- Peripheral Arterial Disease
- Cerebrovascular Disease
54
The “3 Polys”
-Polyuria
-Polydipsia
-Polyphagia
55
- excess glucose is thrown in the kidneys. Glucose renal excretion needs
water excretion
Polyuria
56
- loss of water due to polyuria induces thirst
Polydipsia
57
- reduced glucose introduced to cells lowers energy, thus increasing
hunger
Polyphagia
58
- defined as glucose intolerance first
recognized during pregnancy
- conveys both short and long term
risk to both mother and offspring
Gestational Diabetes
59
- With increased usage of sugar but low production
- Due to: Insulin overdose, increased hypoglycemic agent, liver dysfunction
Hypoglycemia
60
the following symptoms of hypoglycemia:
-Increased hunger -Sweating,
-Nausea
-Vomiting
-Dizziness
-nervousness
-Shaking
-Blurring of speech and sight
-mental confusion
61
can be used for HbA1C or
for self-monitoring of glucose
Whole blood
62
most commonly used specimen
Serum
63
used to inhibit
glycolysis
Sodium Fluoride
64
Chemical Methods
1. Alkaline Copper Reduction Methods
-Folin Wu Method
- Nelson Somogyi Method
2. Alkaline Ferric Reduction Method
3. Ortho-Toluidine (Dubowski Method)
65
Most accurate redox method and believes
to be a measure of true glucose
Nelson Somogyi Method
66
a method to cuprous ions
forming cuprous oxide in hot alkaline solution by glucose
Alkaline Copper Reduction Methods
66
Measured calorimetrically and compared with a standard
Folin Wu Method
67
- “Hagedorn Jensen”
- A titrimetric method
Alkaline Ferric Reduction Method
68
- Most specific non-enzymatic method for
glucose
- condenses with the
aldehyde group of glucose in a hot acetic
acid solution
Ortho-Toluidine (Dubowski Method)
69
- Reference method
- Highly accurate and precise but is time
consuming
Hexokinase Method
69
Enzymatic Methods
1. Glucose Oxidase Method
2. Hexokinase Method
3. Glucose Dehydrogenase Method
70
- Highly specific for B-d-glucose
Glucose Oxidase Method
71
- Involves measurement of NADH
production
Glucose Dehydrogenase Method
72
Testings
-Fasting Blood Sugar
-Random Blood Sugar
-2 Hours Post Prandial -Blood Sugar
-Glucose Tolerance Test
73
- Measures blood sugar after 8-10 hours of
fasting
Fasting Blood Sugar
74
- “Casual blood glucose test”
- Measured to aid in diagnosis of diabetes
Random Blood Sugar
75
- A variation of this test is using a standardized solution containing 75g of
glucose
2 Hours Post Prandial Blood Sugar
76
- One of the laboratory’s hallmark in diagnosis of type 1 and type 2 diabetes
- 3 days before OGTT, individuals should ingest at least 150g/day of
carbohydrates
-Test is performed after an overnight fasting of 8-14 hours
Glucose Tolerance Test
77
- Single dose method
Janney-Isaacson Method
78
Glucose Loads OGTT load (WHO standard)
75 grams
78
- Double-dose/Divided Oral dose method
Exton Rose Method
79
Glycosylated Hemoglobin methods:
● Ion-Exchange Chromatography
● Electrophoresis
● Isoelectric Focusing
● Affinity Chromatography
● Immunoassays
80
- Short term: 2-3 weeks
- For patients with RBC lifespan problems
Fructosamine Test
80
- Formation of a hemoglobin compound
produced when glucose reacts with the amino group of hemoglobin
- glucose molecule attaches non-enzymatically
Glycosylated Hemoglobin
81
normal level of Glycosylated Hemoglobin
4.5%-8%
82
- Used to monitor the pancreas
- Method: Immunometric assay
C-peptide Test
