Lecture 2

Question 1

What is the difference between and single beam and double beam Spectrophotometers?

Answer 1

Double beam has a chopper that splits the light into 2 different portions into 2 separate cuvette.

Question 2

What is the advantage of a double beam Spectrophotometers?

Answer 2

equivalent to having two identical spectrophotometers: one for measuring I and one for Io
This allows Abs values to be collected at different wavelengths without needing to rescan
allows for quick collection of an Absorption spectrum

Question 3

Spectrophotometer with aphotodiode array detector

Answer 3

Light is not separated into different wavelengths until after it goes through sample
Monochromator positioned after the light has passed through sample

Question 4

why does Spectrophotometer with a diode laser light source does not need a monochromator?

Answer 4

Laser puts out light that is such a narrow range of wavelengths it is often described as a single wavelength

Question 5

What is the advantage of a Spectrophotometer with a diode laser light source?

Answer 5

small inexpensive spectrophotometers

Question 6

What is the disadvantage of a Spectrophotometer with a diode laser light source?

Answer 6

the instrument can only measure at the wavelength or wavelengths that it has laser lines at

Question 7

Bandpass

Answer 7

The range of wavelengths that are measured together as a group in a spectrophotometer

Question 8

Osmoles

Answer 8

all of the moles that contribute to osmotic pressure

Question 9

Which compounds can dissolve into ions

Answer 9

Acids and ionic compounds
Not molecular compounds

Question 10

Hypertonic solution

Answer 10

cell in a hypertonic solution, lower concentration ions in cell
H20 leaves cell
Cell shrivels like a raisin

Question 11

Hypotonic solution

Answer 11

higher concentration of ions inside cell
H2O enters cell
Cell inflates and bursts

Question 12

Osmolarity

Answer 12

refers to the number of solute particles per 1 L of solvent
Temperature dependent
Osmolarity = osmoles/liter

Question 13

Osmolality

Answer 13

refers to the number of solute particles in 1 kg of solvent
Independent of freezing point depression

Question 14

Freezing point depression

Answer 14

T=Kfm

Question 15

Serum Osmotic Gap

Answer 15

Measured Osmolality – Estimated Osmolarity

Question 16

Measured Osmolality

Answer 16

Measured by T/Kf

Question 17

Estimated Osmolarity

Answer 17

2*sodium (most important)
Glucose
BUN
Measured in in routine blood tests

Question 18

Abnormally high blood osmolality

Answer 18

dehydration, hypernatremia
head trauma
hyperglycemia, diabetes insipidus
uremia
poisoning from ethanol, ethylene glycol, or methanol
accumulation of toxins in the patient’s blood

Question 19

Abnormally low blood osmolality

Answer 19

excess fluid intake or over hydration, hyponatremia/ or low blood sodium,
paraneoplastic syndromes; a type of disorder that affects some people with cancer,
syndrome of inappropriate ADH secretion (Anti-Diuretic Hormone)

Question 20

Serum Osmotic Gap: Facts

Answer 20

Values up to 10 are borderline normal
normal gap reflects all other substances that are dissolved in the serum but that are not routinely measured

Question 21

Serum Osmotic Gap: Over

Answer 21

Values >10 reflect dissolved substances of low molecular weight- such as:
Drinking alcohol, Solvents from poisoning

Question 22

Sodium ions

Answer 22

The major extra cellular cation
Absorbed passively and excess- excreted by kidneys
Parallels Cl- concentration in healthy individuals
affected by diarrhea/vomiting, excessive sweating

Question 23

Potassium ions

Answer 23

K+ higher inside cells

Question 24

High K+ in blood (outside reference range) can indicate

Answer 24

Renal failure
Releases K+ creating false high K+ levels
Poor technique in blood collection, sample not centrifuged within timely fashion

Question 25

Chloride ion

Answer 25

Major extracellular anion
Counterion to maintain charge balance
Most dietary chloride is absorbed

Question 26

Cystic fibrosis

Answer 26

high sodium and chloride levels in sweat indicate CF

Question 27

pilocarpine

Answer 27

Can induse intense sweating
used to diagnose acidosis/alkalosis

Question 28

Respiratory Acidosis

Answer 28

result of the retention of CO2

Question 29

Chronic Metabolic Acidosis

Answer 29

result of the production of organic acids at a faster rate than they can be metabolized fully

Question 30

Metabolic acidosis

Answer 30

hyperchloremia (high Cl-) without hypernatremia (high Na+)

Question 31

Metabolic alkalosis

Answer 31

hypochloremia (low Cl-) without hyponatremia (low Na+)

Question 32

Anion gap

Answer 32

Na+ + K+ - Cl- - HCO3-
Total positive charge = Total negative charge
used as a check that electrolyte levels are all in a normal balance without actually measuring all of them

Question 33

Dilution factors

Answer 33

Ratios of total volume of solution to volume of solution that was diluted containing substance of interest

Question 34

% Concentration Units

Answer 34

All are ratios of the amount of dissolved substance to the total mass or volume of the solution