Module 2: Carbohydrates

Question 1

Glucose (fasting) reference range

Answer 1

3.3 - 6.0 mmol/L

Question 2

Glucose (random) reference range

Answer 2

3.3 - 11.0 mmol/L

Question 3

The most common form of glucose in the body

Answer 3

Beta-D-glucose

Question 4

Which cells have enzymes for gluconeogenesis?

Answer 4

Hepatic cells and renal tubular cells

Question 5

Low blood glucose causes release of:

Answer 5

Glucagon from pancreatic alpha cells

Question 6

High blood glucose causes release of:

Answer 6

Insulin from pancreatic beta cells

Question 7

3 main classifications of carbohydrates

Answer 7

Monosaccharides, oligosaccharides (1-10 monosaccharides), polysaccharides (more than 10 monosaccharides)

Question 8

3 main dietary monosaccharides

Answer 8

Glucose, fructose, galactose

Question 9

Isomers

Answer 9

Molecules with the same molecular formula, but different arrangements

Question 10

3 common disaccharides and the monosaccharides that make them

Answer 10

Sucrose = glucose + fructose
Lactose = galactose + glucose
Maltose = glucose + glucose

Question 11

The enzyme that digests starch and its two sources in the body

Answer 11

Amylase - saliva and pancreatic juice

Question 12

Which class of carbohydrates are absorbed?

Answer 12

Monosaccharides

Question 13

Carbohydrates

Answer 13

Organic biomolecules composed mostly of carbon, hydrogen, and oxygen
They can be either aldehydes or ketones

Question 14

Gluconeogenesis

Answer 14

Conversion of non-carbohydrates into glucose

Question 15

Glucose oxidase converts glucose into gluconic acid and:

Answer 15

Hydrogen peroxide

Question 16

Hexokinase catalyzes the formation of what?

Answer 16

Glucose-6-phosphate

Question 17

In which glucose assay is the rate of oxygen disappearance measured?

Answer 17

Glucose oxidase

Question 18

Which method is most specific for beta-D-glucose?

Answer 18

Glucose oxidase

Question 19

Reference range for HbA1c

Answer 19

4.0-6.0% of total Hb

Question 20

Ketone bodies

Answer 20

Acetone
Acetoacetic acid
Beta-hydroxybutyric acid

Question 21

What is measured as a signal in an amperometric glucose oxidase method?

Answer 21

Consumption of O2

Question 22

What is measured as a signal in a colormetric glucose oxidase method?

Answer 22

Oxidized chromogen

Question 23

What is measured as a signal in a glucose hexokinase method?

Answer 23

NADPH

Question 24

Which sample type has lower glucose levels: serum or whole blood. By how much, and why?

Answer 24

Whole blood has lower glucose levels by approx. 10% because of volume (glucose is measured by concentration)

Question 25

Lab criteria for determining the presence of diabetes mellitus

Answer 25

2 of the following on different days:
Fasting glucose >7.0mmol/L
2h PP glucose >11.1mmol/L
Random glucose >11.1mmol/L with symptoms
HbA1c >= 6.5%

Question 26

What 2 monosaccharides make up sucrose?

Answer 26

Glucose and fructose

Question 27

What 2 monosaccharides make up lactose?

Answer 27

Glucose and galactose

Question 28

What 2 monosaccharides make up maltose?

Answer 28

2 glucose molecules

Question 29

Glycogenesis

Answer 29

Conversion of glucose to glycogen in the cell (for storage)

Question 30

Glycogenolysis

Answer 30

Conversion of glycogen to glucose in the cell (release of stored glucose)

Question 31

Anaerobic glycolysis

Answer 31

Non-oxygen dependent catabolism of G-6-P (via the Embden-Meyerhof pathway) into 2 pyruvates; and in anaerobic conditions (mainly in muscle), conversion of pyruvate into lactate

Question 32

Aerobic glycolysis

Answer 32

Further oxygen dependent oxidation of pyruvate in the mitochondria occurs to produce a lot of ATP and reduced coenzymes (eg. NADH)

Question 33

The typical difference between serum and whole blood glucose values

Answer 33

Whole blood values are about 10% lower than serum

Question 34

What would be the effect on the HbA1c result in a patient with a chronic hemolytic anemia?

Answer 34

Falsely decreased