Unit 6 - Redone Flashcards
Basic carbohydrate composition
Carbon
Hydrogen
Oxygen
Reducing sugars
Fructose
Glucose
Galactose
What is a reducing sugar? What does it contain and what does it do?
It is a sugar with an aldehyde group, capable of reducing cupric to cuprous
What is the significance of monosaccharides taking on different forms
Polarize light in different directions
Mono vs Di saccharides
Mono: Fructose Glucose Galactose
Di: Sucrose Maltose Lactose
storage carbohydrates of animals
Glycogen
storage carbohydrates of plants
Starch
Where is glycogen stored
Liver
If glycogen stores are full, what happens to glucose?
Turned into triglycerides and stored as fat
Glucogenesis
Liver converts non glucose monosaccharides into glucose
What begins the breakdown of carbs?
Salivary amylase
Glycogenesis
Liver stores glucose as glycogen
Glycogenolysis
Liver breaks down glycogen for glucose
Gluconeogenesis
Glucose is produced from non-carbohydrate sources
What noncarb sources are used to make glucose?
Lipids
Amino Acids
Glycerol
Lactate
Lipogenesis
Fat formation with excess glucsoe
Where is insulin produced
Beta islets of langerhans
Where is glucagon produced
Alpha islets of langerhans
Cortisol levels in Cushing Syndrome
High
Cortisol levels in Addisons DIsease
Low
This is released in response to high glucose levels
Insulin
Specimens for Glucose testing
Serum
Plasma - NaF or Heparin
Whole Blood - Capillary
CSF - Centrifuge and test supernatant ASAP
Urine
Dipstick uses which method?
Glucose oxidase
Glucose levels in the urine should be…
Undetectable
Normal fasting plasma glucose
74-99 mg/dL
If not separated, how much do glucose levels go down?
5-7% per hour
Glycolysis is primarily done by which cells?
WBC
Removal of glucose should be done according to CLSI
Less than 2 hours, but really ASAP
Best specimen for glucose testing?
Gel barrier tube
Separated specimens are stable for how long?
RT - 8 hours
Fridge - 3 days
How does HCT affect glucose levels?
higher HCT, lower glucose
Neonates
CSF Glucose vs Plasma Glucose
CSF glucose 60% of plasma glucose
WB glucose vs plasma glucose
WB 10-15% lower than serum
Why is WB glucose lower than plasma glucose
Dilution effect from the red blood cells
Renal Threshold for Glucose
160-180 mg/dL
Renal Glycosuria
People who have low renal thresholds
A patient just ate a meal before getting their blood drawn. What should their urine glucose levels look like?
None to low levels
What interferes with the clinitest?
Ascorbic acid
Current methods to measure glucose
Enzymatic
Hexokinase
Detect NADPH production at 340nm using tetrazolium color reagent
Glucose oxidase
Detect production of hydrogen peroxide or consumption of oxygen
Glycation of hemoglobin is ___ and ___
Nonenzymatic and irreversible
Hgb A1c reflects plasma glucose levels over..
8-12 weeks
Hgb A0 =
Non-glycated hemoglobin
Hgb A1 =
glycated hemoglobin
Hgb A1c is…
hgb with glucose attached to the amino terminus of the beta chain
Specimen for glycated hemoglobin
EDTA
stable at 4C for 1 week
What percent of glycated hemoglobin is hemoglobin A1c
80%
Hgb A1c Reference range
4-6%
Methods of detecting hemoglobin A1c?
Detect bond
Detect charge difference
Enzymatically split glycated portion off and measure it
When should hemoglobinopathy be suspected?
When hgb <4% or >15%
How does IDA affect Hgb A1c levels?
False increase up to 1.5%
when can you test Ghgb levels in IDA?
When its gone
how does renal insufficiency affect Ghgb levels?
False decrease; inc of urea causes it to bind to the N terminus
True hypoglycemia
Liver issues
Diet
Overtaking diabetes meds
How do young cells affect Ghgb levels?
Decrease, more young cells = Ghgb decrease
Fructosamine
Fructose + Albumin
- Detects early diabetes or useful in hemoglobinopathies
Ketones detected in serum or urine
Acetone, acetoacetate, beta-OH butyrate
Proinsulin
Breaks into insulin and C-peptide
High insulin
Low C peptide
Artificial insulin injection
High insulin High C peptide
Possible beta cell tumor
Microalbumin
Detect early renal nephropathy
Type 1 diabetes
Antibodies to the islet cells
