Question

-What is HIF1? What does it do for all of this in some tumors?

-What is the Cori cycle, what does it do, and why does it matter?

Answer 1

Please find the answers below:

Answer 1: The HIF1 or hypoxia inducible factor 1 is a transcription factor which encodes for a specific types of proteins in a cell under the conditions of hypoxic stresses such as decreased oxygen availability to the cells. The HIF1 is not expressed normally but undergoes expression only under hypoxic conditions. These proteins can also be found under cancerous conditions. This is because the cancerous callus contains a bulk of cells in the core which has low oxygen tension. This reduces the total content of oxygen in the cells and activates the HIF1 genes. This causes excessive angiogenesis in the tumor cells and help in invasion of the nearby tissue.

Answer 2: The Cori's cycle is a natural biochemical cycle taking place in the liver and muscles which is actively engaged in bio-conversion of glucose to lactic acid. The steps of this cycle involve:

1. Generation of glucose in the liver by gluconeogenesis or glycogenolysis
2. Transfer of glucose to the muscle via blood stream
3. Metabolism of the glucose in controlled amount of oxygen to generate lactic acid

Function: The Cori's cycle is invovled in metabolism of sugars in anaerobic or hypoxic conditions when aerobic metabolism cannot take place.

Significance: The absence/decline in oxygen availability accounts for incomplete combustion of glucose and hence accumulation of toxic wastes such as lactic acid which cause fatigue in the muscles. However, the spontanity of this cycle accounts for providing energy to the muscles when urgently required.