Carbohydrates

Question 1

How are carbs classified?

Answer 1

Grouped into generic classifications based on the number of carbons in the molecule

Question 2

What is a Monosaccharide, Dissaccharide, Oligosaccharide, Polysaccharide

Answer 2

mono - 1 carbon
Diss - 2 carbon
Oligo - 3-10 carbons
Poly - 10+ carbons

Question 3

Are carbs reducing substances?

Answer 3

Yes, these carbs can reduce other compounds while themselves are oxidized (remember the Clinitest)

Question 4

Define Glucose

Answer 4

Glucose is the primary source of energy for humans.

Question 5

Can the nervous system store/concentrate carbs?

Answer 5

No

Question 6

What are the 3 possible metabolic pathways for glucose?

Answer 6

1. Embden-Meyerhof pathway (hexokinase starts)
2. Hexose monophosphate pathway (HMP) (G-6-phosphate)
3. Conversion to glycogen

Question 7

What is the 1st step for all 3 metabolic pathways for glucose?

Answer 7

First step for all three pathways requires glucose to be converted to glucose-6-phosphate using the high-energy molecule, ATP.

Question 8

Define gluconeogenesis

Answer 8

Conversion of amino acids by the liver and other specialized tissue, such as the kidney, to substrates that can be converted to glucose

Formation fo glucose-6-phosphate from noncarbohydrate sources

Question 9

What happens in the Embden-Meyerhof pathway?

Answer 9

Starts with 2 ATP molecules and ends with 4

Takes place in Mitochondria

Hexokinase starts

Conversion of amino acids by the liver and other specialized tissue, such as the kidney, to substrates that can be converted to glucose-6-phoshate is called gluconeogenesis

In anaerobic conditions, like in muscles, by converting pyruvic acid to lactic acid.

Question 10

What happens in the Hexose monophosphate pathway (HMP)

Answer 10

Detours from Embden-Meyerhof path by converting glucose-6-phosphate to 6-phosphogluconic acid

Produces NADPH which is important to cells lacking mitochondria, preservation of cellular membranes and enzymes

Question 11

Conversion to glycogen

Answer 11

Occurs when cellular energy needs are met

Acts as energy storage

Question 12

Define glycolysis

Answer 12

Metabolism of glucose molecule to pyruvate or lactate for production of energy

Question 13

Define Glycogenesis

Answer 13

Conversion of glucose to glycogen for storage

Question 14

Define Glycogenolysis

Answer 14

Breakdown of glycogen to glucose for use as energy

Question 15

Define Lipogenesis

Answer 15

Conversion of carbohydrates to fatty acids

Question 16

Define Lipolysis

Answer 16

Decomposition of fat

Question 17

What are all involved in controlling the blood glucose concentrations within a narrow range?

Answer 17

Liver, pancreas, and other endocrine glands are all involved in controlling the blood glucose concentrations within a narrow range.

Question 18

is the primary hormone responsible for the entry of glucose into the cell and therefore reducing blood glucose levels?

Answer 18

Insulin

Question 19

What is the primary hormone responsible for increasing blood glucose levels

Answer 19

Glucagon (liver muscle)

Question 20

What are the two hormones produced by the adrenal gland that affect carbohydrate metabolism?

Answer 20

Epinephrine
Glucocorticoids

Question 21

What is Epinephrine?

Answer 21

Produced by the adrenal medulla, increases plasma glucose. (skeletal muscle)

Question 22

What is Glucocorticoids?

Answer 22

Primarily cortisol, are released from the adrenal cortex on stimulation by adrenocorticotropic hormone (ACTH).

Question 23

What is Diabetes Mellitus?

Answer 23

A group of metabolic diseases characterized by hyperglycemia (increase in glucose) resulting from defects in insulin secretion, insulin action, or both

Question 24

What is Type 1 Diabetes Mellitus

Answer 24

B-cell destruction to absolute insulin deficiency and development of autoantibodies (includes latent autoimmune diabetes of adulthood)

“genetic”

Islet cell autoantibodies
Insulin autoantibodies
Glutamic acid decarboxylase autoantibodies
Tyrosine phosphatase IA-2 and IA-2B autoantibodies

5-10% of all cases

Commonly occurs in childhood with rapid onset

Tend to experience Ketoacidosis (buildup of ketones in blood)

Symptoms: Excessive thirst (polydipsia), increased food intake (polyphagia), excessive urination (polyuria), rapid weight loss, confusion, loss of consciousnesses

Question 25

What is Type 2 Diabetes Mellitus

Answer 25

Insulin resistance with an insulin secretory defect (due to progressive loss of adequate B-cell insulin secretion) Relative insulin deficiency due to insulin resistance "Acquired" Occurs due to insulin resistance combined with insulin secretory defect Most common form of Diabetes Mellitus Associated with obesity and lack of physical exercise Tends to occur in adulthood

Question 26

What is gestational diabetes?

Answer 26

Glucose intolerance during pregnancy diagnosed in the 2nd or 3rd trimester of pregnancy

Question 27

What is is lab findings in Hyperglycemia? _____ insulin _____ Glucose in plasma and urine _____ Urine SG _____ Serum and urine osmolality _____ Blood and urine pH (acidosis) Electrolyte imbalance Are there Ketones in serum and urine? (Ketonemia and Ketonuria)

Answer 27

Decreased or absent insulin Increased Glucose in plasma and urine Increased Urine SG Increased Serum and urine osmolality Decreased Blood and urine pH (acidosis) Electrolyte imbalance Are there Ketones in serum and urine? (Ketonemia and Ketonuria)

Question 28

Impaired fasting glucose or Prediabetes

Answer 28

When fasting glucose is elevated but not to diabetic levels Criteria for Testing: - Habitually inactive - Family History of Diabetes Mellitus - At risk minority populations - History of Gestational Diabetes (diabetes from pregnancy) - Hypertension (high blood pressure) - Low HDL cholesterol (good cholesterol) - High Triglycerides (fat) - Glycosylated Hemoglobin A1c ≥ 5.7 - History of glucose intolerance - Insulin resistance

Question 29

Gestational Diabetes Mellitus

Answer 29

Any degree of glucose intolerance that occurs in the 2nd or 3rd trimester of pregnancy Can lead to severe hypoglycemia of baby when umbilical cord is cut Women who meet the criteria below in their prenatal visit should be diagnosed with Diabetes Mellitus not Gestational Diabetes Mellitus

Question 30

Pathophysiology of Diabetes Mellitus (symptoms)

Answer 30

Excessive thirst (polydipsia) Increased food intake (polyphagia) Excessive urination (polyuria) Rapid weight loss Confusion Loss of consciousnesses Glycosuria Diabetic Keto Acidosis Hyperkalemia from the displacement of Potassium Heart Disease Stroke Pancretatits (inflammation)

Question 31

Criteria for Diagnosis of Diabetes Mellitus

Answer 31

Normal glucose = 74 - 100 mg/dL Impaired fasting glucose = 100 - 125 mg/dL Provisional diabetes diagnosis = > 126 mg/dL

Question 32

Criteria for the Testing and Diagnosis of Gestational Diabetes Mellitus

Answer 32

Plasma glucose decreases as hours of test increases One step: Fasting plasma glucose = > 92 mg/dL 1-h plasma gl = >180 mg/dL 2-h plasma gl = >153 mg/dL Two step: Fasting plasma glucose = > 95 mg/dL 1-h plasma gl = > 180 mg/dL 2-h plasma gl = > 155 mg/dL 3-h plasma gl = > 140 mg/dL

Question 33

Hypoglycemia

Answer 33

Involves decreased plasma glucose levels and can have many causes—some are transient and relatively insignificant, but others can be life threatening Level 1 (glucose alert value) = < 70 mg/dL Level 2 (clinically significant hypoglycemia) = < 54 mg/dL Level 3 (severe hypoglycemia) = No specific glucose threshold....below range

Question 34

Methods of glucose measurement

Answer 34

Serum (no anticoagulant), plasma, or whole blood Hexokinase method measured at 340 nm (wavelength being isolated)

Question 35

Sample integrity

Answer 35

Sample must be separated, serum/plasma poured off and refrigerated within 1 hour to maintain specimen integrity Use serum or Plasma from lithium/sodium heparin or sodium flouride Fasting blood glucose levels are to be collected after 8-10 hours of fasting, no more than 16 hours Falsely increased by reducing agents Hemolyzed and Icteric (yellow) samples may by falsely decreased

Question 36

Glucose Tolerance Testing

Answer 36

Purpose is to evaluate how the body reacts to glucose Procedure begins with a fasting glucose level Patient orally consumes a 75 g glucose solution 2 hours later another glucose level If the 2 hour glucose result is >200 mg/dL the patient is diagnosed with Diabetes Mellitus Glucose level is drawn every hour for evaluation of pregnant women Normal glu tolerance = < 140 mg/dL Impaired glu tolerance = 140 - 199 mg/dL Provisional diabetes diagnosis = > 200 mg/dL

Question 37

Glycosylated Hemoglobin

Answer 37

Defined as the formation of a hemoglobin compound when glucose (a reducing sugar) reacts with the amino group of hemoglobin Rate of formation is directly proportional to plasma glucose levels over 3 months HbA1c is most commonly measured glycosylated Hemoglobin Normal range is 4.0% - 6.0% (< 5.7% < 39 mmol/mol) Uses EDTA whole blood sample

Question 38

Ketones

Answer 38

Produced by the liver through metabolism of fatty acids to provide a ready energy source from stored lipids at times of low carbohydrate availability

Question 39

Albuminuria

Answer 39

An early sign that diabetic kidney disease is occurring is an increase in urinary albumin.

Question 40

Islet Autoantibody, Insulin Testing, and C-Peptide Testing

Answer 40

Presence of autoantibodies to the β-islet cells of the pancreas is characteristic of type 1 diabetes.