Carbs Flashcards
The 4 structural properties to classify carbs:
- Size of base carbon chain
- location of CO function group
- Number of sugar units
- Stereochemistry of the compound
Symptoms of diabetes Mellitus
- Polyuria
- Polydipsia
- Unexplained weight loss
Diagnostic criteria for diabetes mellitus
1) HbA1c >6.5%
2) Fasting plasma glucose >126 mg/dL
3) 2-h plasma glucose >200 mg/dL
4) Random plasma glucose >200 mg/dL plus symptoms of diabetes
D- and L-glucose are ____
Stereoisomers
What are the bonds between two monosaccharides?
Glycosidic Linkage
What causes hypoglycemia?
Insulin overdose, drugs, alcoholism, inulinemia, galactosemia, glycogen storage diseases
Glycolysis
Metabolism of glucose molecule to pyruvate or lactate for production of energy
Glucose —-> CO2 + H2O + ATP
Gluconeogenesis
Formation of G6P from non carbohydrate sources
Non-CHO sources —-> glucose
Glycogenolysis
Breakdown of glycogen to glucose for use as energy
Glycogen —-> glucose
Glycogenesis
Conversion of glucose to glycogen for storage
Glucose —-> glycogen (liver, muscle)
Lipogenesis
Conversation of carbohydrates to fatty acids
Lipolysis
Decomposition of fat
What is the fed state?
Increase in insulin from the pancreatic beta cells (islets of Langerhans). When insulin is increased you have glycogenesis. When insulin is decreased you have glycogenolysis and gluconeogenesis.
What happens in the fasting state?
Glucagon from the pancreatic alpha cells are released and glycogen is converted to glucose.
What happens during fight or flight?
Similar to glucagon, but epinephrine from the adrenal medulla is released.
Where does glycogenolysis and gluconeogenesis occur?
Liver
Where does glucose uptake and lipogenesis occur?
Adipose tissue
Where foes glucose uptake and glycolysis occur?
Muscle
What do alpha pancreatic islet cells do?
Stimulates glucagon which will stimulate glycogenolysis and gluconeogenesis
What do beta pancreatic islet cells do?
Stimulates insulin which then stimulates glucose uptake/lipogenesis and glucose uptake/glycolysis. Insulin also inhibits glycogenolysis and gluconeogenesis.
Classification of Type 1 diabetes
Type 1a: beta cell destruction from AI process that leads to an absolute insulin deficiency
Type 1b: idiopathic
Classification of type 2 diabetes
Insulin resistance in peripheral tissues and an insulin secretory defect of the beta cell. Associated with family history of diabetes, older age, obesity, lack of exercise.
Pathogenesis of gestational diabetes
Glucose intolerance during pregnancy diagnosed in the second or third trimester of pregnancy. A frequent but transitory glucose intolerance. Two of the four glucose results need to be abnormal
Level 1 glucose alert
Sufficiently low for treatment with fast acting carbohydrate and dose adjustment of glucose lowering therapy
Level 2 clinically significant hypoglycemia
Sufficiently low to indicate serious, clinically important hypoglycemia
Severe hypoglycemia
Hypoglycemia associated with severe cognitive impairment requiring external assistance for recovery
Renal threshold
Proximal convoluted tubule reabsorbs all glucose if <180 mg/dL. The glycolysis results if blood glucose >180 mg/dL
Specimens used for glucose determination
WB, Plasma, CSF, Urine
What is glycated hgb
Hemoglobin A1C. An irreversible reaction occurring throughout the 120 day life span of an RBC. Gives an idea of average blood sugars over 90 days.
Ref: 3-6% of total hgb
For every 1% decrease in HBA1C, it reduces the risk of microvascular complications by ____
35%
How do you determine HbA1C for hemolyzed whole blood?
Turbidimetric inhibition immunoassay (TINIA)
Approximately how much A1C makes up the estimated average glucose?
36% of the estimated average glucose will be the ICC of HbA1C
What is the problem in glycogen storage diseases?
There is a lack of enzymes of glycogen metabolism
What is the problem in lactose intolerance?
There is a deficiency in intestinal mucosal lactase. A GTT is done for a baseline and an abnormal result with be a flat curve.
Ketones are a result of ____
uncontrolled diabetes mellitus
