Dietary variation (experiment)

Question 1

Protocol:

1. Volunteers keep a record of food eaten for each meal (each group is assigned a special diet) and begin 2 days before the experiment.
2. During this period, urine will be collected over a 24 hour period beginning on the 2nd morning of the special diet, and ending the following morning on the day of the experiment
3. Secure toluene from the lab to preserve urine specimens, keep samples refrigerated.
4. To avoid cloudiness of the serum due to increased lipid content, volunteers are advised to minimize intake of fatty foods during breakfast on the day of the experiment.
5. Have blood extracted; pH and specific gravity will be determined using urine analysis strips.
6. Bring urine samples to school on the day of the experiment

Answer 1

REMEMBER

Question 2

Titratable Acidity and NH3 determination

Answer 2

25 ml urine in 250 ml Erlenmeyer flask => 5 g K+ oxalate, 1-2 drops phenolphthalein => Shake and titrate w/ 0.1 NaOH, Add 10 ml formalin

Question 3

Serum Creatinine/Urine Creatinine

Answer 3

1.5 mL picric acid, 1.5 ml base reagent, 0.1 ml deionized H2O, 0.1 ml serum/urine sample => Mix and incubate 37°C x 15 minutes, Spectro 510 nm

Question 4

Serum Uric Acid/Serum BUN

Answer 4

2.5 ml URI-ZYME buffer OR 0.5 ml UREA COLOR REAGENT => Unknown test tube: 0.05 ml serum OR 0.01 ml serum => Add appropriate reagent

Question 5

Major end product of protein nitrogen metabolism

Answer 5

Urea

**Synthesized in liver from ammonia, which is produced by amino acid deamination

Question 6

Hydrolysis of urea in the presence of urease to yield what products?

Answer 6

CO2 and NH4+ ions

Question 7

Ammonium in the presence of hypochloric acid forms what product?

Answer 7

Chloramines

Question 8

Berthelot’s reagent

Answer 8

Alkaline solution of phenol and hypochlorite

• *In this case the less toxic sodium salicylate substitutes for phenol
• *Forms a blue complex (indophenol chromophore) which can be measured spectrophotometrically at 630 nm

Question 9

Oxidation of uric acid in the presence of uricase Forms what product?

Answer 9

Allantoin and hydrogen peroxide

Question 10

Hydrogen peroxide reacts with a polyhalogenated benzoic acid (PHBA) and 4-aminoantipyrine (4-AAP) to yield what product?

Answer 10

Quinoneimine and water

Question 11

What increase turnover of nucleic acids?

Answer 11

Myeloproliferative syndromes and Chemotherapy for leukemias and lymphomas

Question 12

Accumulation of purine precursors due to specific enzyme pathway deficiencies or defects

Answer 12

Lesch-Nyhan Syndrome

Question 13

In the experiment, what reaction was used in the determination of urine creatinine?

Answer 13

Jaffe reaction
**Reaction of creatinine with picric acid under alkaline conditions that forms a red-colored product measurable at 510 nm

Question 14

Measures the amount of dissolved solutes or solids in the urine

Answer 14

Urine specific gravity

Question 15

Titratable acid normal values

Answer 15

150 – 500 ml of 0.1N acid/day or 15- 50 mEq H+/day

**multiply mL values by 0.1 to get mEq

Question 16

TA (titratable acidity; ml acid/day)

Answer 16

(Y)(Y1)/25

**Where, Y = vol. (ml) of 0.1N NaOH used, Y1 = vol. of 24-hr urine, 25 = vol. of urine used in the test

Question 17

Titratable acidy to urine is due to?

Answer 17

Acid phosphates

• *It can be determined by titrating urine with a standard alkali using phenolphthalein as indicator
• *Potassium oxalate is added to precipitate calcium which might form calcium phosphate on neutralization of urine affecting the actual endpoint

Question 18

Synthesized in renal cells by the hydrolysis of glutamine, transdeamination, as well as oxidative deamination

Answer 18

Ammonia

• *Based on the reaction that takes place when formalin solution is added to a solution containing ammonium salts
• *An acid reaction is produced, which is then titrated with standard NaOH using phenolphthalein as indicator