BIOC2: Week 9 - Purines

What is the required form of folate for purine synthesis?

• DHF

• N-10-formyl THF

• N-5-N-10-methylene THF

• THF

Where does the sugar in synthesized nucleic acids come from?

• glucose directly from circulation

• ribose from PPP

• diet

SCID is caused by a deficiency of which enzyme?

• ADA

• PRPP

• HGPRT

A 2 year old male patient presents with intellectual disability, hyperuricemia, chorea (involuntary jerking movements), aggression, and compulsive lip and finger biting. Which reaction is compromised?

• IMP + aspartate --> adenylosuccinate

• Adenine + PRPP --> AMP

• xanthine --> uric acid

• Guanine + PRPP --> GMP

After missing a few feedings, a newborn becomes quite lethargic, and the parents rush the child to the emergency department. Blood analysis indicates elevated levels of lactate and uric acid and significantly decreased levels of glucose. After stabilizing the child with glucose infusions, a glucagon challenge is given to the infant, and blood glucose levels do not increase.

The accumulation of which metabolite in the liver is most responsible for the elevated uric acid seen in the circulation?

• glucose

• lactate

• ribose-5-P

• thymidine

• acetoacetate