Question
A person obtains cells cultured from various tissues to study the effect of increased extracellular glucose concentration. Following the incubation of these cells in 5% dextrose, he measures the intracellular fructose concentration. The concentration of fructose is highest in cells obtained from:
| A. | Iris |
| B. |
Retina |
| C. |
Ovary |
| D. |
Kidney |
|
Correct Answer � C Explanation |
 |
Ans. C. Ovary
Ovarian, seminal vesicle, and liver cells express both aldose reductase, which reduces glucose to sorbitol, and sorbitol dehydrogenase, which converts sorbitol to fructose. Thus, glucose is converted into fructose in these tissues, and intracellular fructose concentrations are expected to be high. Galactose is a substrate for aldose reductase, forming galactitol, which accumulates in the lens of the eye, causing cataract.