Nitrogen Metabolism

Question 1

Major source of Nitrogen?

Answer 1

Proteins – Amino Acids

Question 2

Where does reabsorption of glucose and amino acids occur in the kidney?

Answer 2

Proximal Convoluted Tubule

Question 3

What transport protein gene superfamily mediates the re-uptake of glucose and amino acids?

Answer 3

SLC gene

Question 4

Hartnup Disease

Answer 4

Defective uptake of NEUTRAL amino acids

- ex. Tryptophan

Question 5

Tryptophan is a precursor for what 3 things?

Answer 5

1. Niacin (NAD)
2. Serotonin
3. Melatonin

Question 6

Defective uptake of Tryptophan is known as?

Answer 6

Hartnup Disease

Question 7

What is the treatment for Hartnup Disease?

Answer 7

High protein diet and Niacin repletion

Question 8

Physical symptoms of Hartnup Disease

Answer 8

Tremor, photosensitivity (rash), nystagmus, failure to thrive

Question 9

Cystinuria

Answer 9

Defective uptake of DIBASIC amino acids
- ex. COAL
= cystine, ornithine, arginine, lysine

Question 10

What form in the kidney with Cystinuria?

Answer 10

Cystine calculi

Question 11

Physical symptoms of Cystinuria

Answer 11

Renal colic, abdominal pain

Question 12

Defective uptake of Dibasic amino acids is known as?

Answer 12

Cystinuria

Question 13

With Hartnup Disease and Cystinuria, what is the double whammy effect?

Answer 13

The transporters that control the reabsorption of the AA in the kidney are the SAME ones that control the absorption in the intestines
= No absorption in the stomach or in the kidney of these AA!

Question 14

Phenylalanine is converted to?

Answer 14

Tyrosine

Question 15

What enzyme converts Phenylalanine to Tyrosine?

Answer 15

Phenylalanine Hydroxylase

Question 16

Phenylketonuria (PKU)

Answer 16

Defect in Phenylalanine Hydroxylase

- Musty urine and impaired brain function

Question 17

What amino acid must you supplement for PKU?

Answer 17

Tyrosine

Question 18

Non-classical PKU has a deficient enzyme of?

Answer 18

Dihydrobiopterin Reductase

Question 19

Tyrosinemias

Answer 19

Increased in blood levels of Tyrosine

Question 20

Tyrosinemias can be seen transiently in?

Answer 20

Newborns

Question 21

Tyrosinemia Type 1 symptom?

Answer 21

Liver failure

Question 22

Tyrosinemia Type 2 symptom?

Answer 22

Ocular manifestations

Question 23

Alkaptonuria has what defective enzyme?

Answer 23

Homogentisate Oxidase

Question 24

Symptoms of Alkaptonuria?

Answer 24

Black urine, black sclera, black IV discs, black bones and arthritis

Question 25

Which Tyrosinemia results in black pigment of bones, urine, etc?

Answer 25

Alkaptonuria

Question 26

Alkaptonuria has a build up of?

Answer 26

Homogentisic Acid

Question 27

What amino acid is the key regulator of Nitrogen?

Answer 27

GLUTAMATE

Question 28

What amino acid is a key regulator of Nitrogen and acts as a Nitrogen donor and acceptor?

Answer 28

GLUTAMATE

Question 29

Glutamate + NH3 (ammonia) =

Answer 29

Glutamine

Question 30

Excess NH3 (ammonia) causes a depletion of?

Answer 30

Glutamate (GABA) and

Alpha - ketoglutarate

Question 31

Excess ammonia (NH3) is toxic to what part of the body?

Answer 31

Brain

Question 32

Gout has high levels of?

Answer 32

Uric acid

Question 33

Uric acid levels are high in what condition?

Answer 33

Gout

Question 34

A diet rich in ____ can lead to gout

Answer 34

Purines

Question 35

What purines in a diet specifically can cause gout?

Answer 35

Seafood, alcohol, beans, meat

Question 36

Defects in any of the 6 enzymes of the urea cycle can cause?

Answer 36

Hyperammonemia

Question 37

Grey baby syndrome due to _____ toxicity

Answer 37

Chloramphenicol

Question 38

Grey baby syndrome causes a deficiency in what enzyme?

Answer 38

UDP - GlucuronylTransferase

Question 39

Infants have what type of jaundice?

Answer 39

Physiological jaundice