Biochemistry Quiz#22 Fructose and galactose metabolism

1. Which of the following enzymes is considered the rate-limiting step in fructose metabolism? 

Question 1 of 7

2. A 5-year-old boy is brought to the pediatrician for a routine check-up. His parents mention that they noticed his urine "smells sweet." Laboratory tests show the presence of fructose in the urine, but the boy is otherwise healthy with normal growth and development. Which enzyme deficiency is most likely responsible for these findings? 

Question 2 of 7

3. Which enzyme represents the rate-limiting step in galactose metabolism? 

Question 3 of 7

4. A newborn girl is found to have jaundice, poor feeding, and lethargy within the first week of life. Laboratory findings include hypoglycemia, elevated liver enzymes, and the presence of galactose in the urine. Which enzyme deficiency is most likely responsible for her condition? 

Question 4 of 7

5. A 2-year-old boy is brought to the ophthalmologist by his parents, who have noticed cloudiness in his eyes. Upon examination, the ophthalmologist diagnoses the child with bilateral cataracts. Further questioning reveals that the child's diet includes regular consumption of dairy products. Laboratory tests show an absence of galactose-1-phosphate in the blood but elevated levels of galactose in both blood and urine. Which enzyme deficiency is most likely responsible for this child's condition? 

Question 5 of 7

6. An 8-month-old infant begins to have vomiting, hypoglycemia, and jaundice after being introduced to fruits, vegetables, and table sugar. A detailed dietary history reveals that the symptoms occur following the ingestion of foods containing fructose, sucrose, or sorbitol. Laboratory tests indicate liver dysfunction. Which enzyme deficiency is most likely responsible for the infant's symptoms? 

Question 6 of 7

7. A 20-year-old woman reports experiencing bloating, flatulence, and diarrhea after consuming dairy products. These symptoms are not present when she avoids lactose-containing foods. Which enzyme's activity is most directly related to her condition? 

Question 7 of 7


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