Final answer:
Glucose is stored as glycogen in the liver and muscle tissue, but at a blood glucose level of 50 mg/dL, it is mobilized to increase blood levels. At a high level of 300 mg/dL, excess glucose may be turned into fat or excreted in urine if it exceeds the renal threshold due to ineffective insulin action in type 1 diabetes.
Step-by-step explanation:
When the blood glucose level is 50 mg/dL in a 20-year-old man with type 1 diabetes, the glucose is initially stored in the liver and muscles in the form of glycogen. This is due to the hormone action of glucagon, which stimulates the breakdown of glycogen into glucose to be released into the bloodstream to elevate blood glucose levels. If the level were 300 mg/dL, this would be an indication of hyperglycemia.
The liver might still store some glucose as glycogen, but once the capacity is exceeded, additional glucose could be converted into fat for storage in adipose tissue. Furthermore, due to the lack of effective insulin action in type 1 diabetes, glucose uptake into cells would be impaired, leading to elevated blood glucose levels. If the glucose level exceeds the renal threshold of 180 mg/100 ml, the kidneys start to excrete excess glucose into the urine, a condition known as glucosuria.