Nitrogen Metabolism

Question 1

What are struvite crystals related to

Answer 1

Bacterial infections

Question 2

What is calcium oxalate related to

Answer 2

Hyperparathyroidsim

Question 3

What is the first step in nitrogen removal

Answer 3

Oxidative deamination

Question 4

What holds the nitrogens to get removed

Answer 4

Glutamate

Question 5

what is the carbon source for transamination reactions

Answer 5

Aspartate

Question 6

What is the rate limiting step of urea cycle

Answer 6

Conversion of ammonia and carbamoyl phosphate via carbamoyl phosphate synthetase and NAG activation

Question 7

Where is nitrogen removed in the kidney

Answer 7

PCT

Question 8

Hartnup and cystinuria are diseases related to ….

Answer 8

H- reuptake of nonpolar AA

C- reuptake of dibasic AA

Question 9

Why are Hartnup and Cystinuria double whammy effects

Answer 9

Because they have both the reuptake issue in the kidney but they also have the uptake issue in the intestines

Question 10

What is the MoA of Hartnup and Cystinuria

Answer 10

Deficient membrane transporters

Question 11

Hartnup is devastating when looking at one particular AA, which one causes the most issues?

Answer 11

Trp

It is used for NT and niacin (energy production)

Question 12

What is a classic symptom of hartnup

Answer 12

Pellagra-like dermatosis

Question 13

What causes a Hartnup event

Answer 13

Sunlight, fever, drugs, emotional or physical stress, or poor nutrition

Question 14

What is the treatment for hartnup disease

Answer 14

Niacin repletion and includes a high-protein diet

Question 15

What is niacin or B3 also called

Answer 15

Nicotinic acid

Question 16

What tissues need niacin more

Answer 16

Tissues that have high energy demands or tissues that have a high turnover rate

Question 17

What are the dibasic AA

Answer 17

COAL
Cystine
Ornithine
Arginine 
Lysine

Question 18

What are the symptoms of cystinuria

Answer 18

Renal colic related to the stones

Question 19

How do we diagnose cystinuria

Answer 19

Nitroprusside test

Question 20

What is the transporter that can help with uptake/reuptake issues

Answer 20

PEPT1 can take up peptides

Question 21

Secondary PKU is an issue with what enzyme

Answer 21

Dihydrobiopterin reductase

Question 22

What enzyme is affected in classic PKU

Answer 22

Phenylalanine hydroxylase

Question 23

What defective enzyme is responsible for albinism

Answer 23

Tyrosinase

Tyrosine—> melanin

Question 24

What is the most common IEM

Answer 24

PKU

Question 25

What are the symptoms of PKU? Treatment?

Answer 25

Musty odor in urine cause by phenylacetate (also blocks AA transport and neurotransmission in the brain)

Limit Phe and supplement Tyr

Question 26

When is it critical to have diagnosed PKU

Answer 26

Before 2 weeks

Question 27

What is the upper limit of Phe in the blood

Answer 27

6 mg/dL

Question 28

What helps with PKU in diet

Answer 28

Treatment of tetrahydropiopterin (5-20mg/kg a day)which is a PAH cofactor

Question 29

What enzyme is linked to type 1 tyrosinemia

Answer 29

Fumaraylacetate hydrolase

Question 30

What is a main symptom of type 1 tyrosinemia

Answer 30

Cabbage smelling urine

Question 31

What enzyme is related to type 2 tyrosinemia

Answer 31

Tyrosine aminotransferase

Question 32

What is the inheritance of alkaptonuria

Answer 32

Autosomal recessive

Question 33

What do we find with alkaptonuria

Answer 33

Black intervertebral disks and urine

Question 34

What triad is associated with alkaptonuria

Answer 34

Homogenistic aciduria, ochronosis, and arthritis