You are here:

Biology/Simple diffusion and Blood Glucose


QUESTION: My question is regarding Blood glucose. I understand that glucose is transported by fasciliated diffusion and cant be transported by simple diffusion because it is too big of a molecule. Lets say someones blood glucose was 400 which is really high. If glucose could move by simple diffusion how would this effect the blood glucose level. I believe it would be higher or the same but not sure. Can you explain this to me. I am taking Pathophysiology.

ANSWER: Hi Kelly
As you have stated Glucose passes through the cell membrane by facilitated diffusion,the carrier molecule being Insulin. When there is a deficiency of insulin the glucose level rises. It is difficult to predict what would happen if there was no insulin nor facilitated diffusion. This would mean that the whole system would be altered and the cell would not be able to function. The cell membrane is attuned to facilitated diffusion and active transport. On the surface it would seem that blood sugars would be lower but I do not believe we can make a prediction based upon the supposition that insulin would not be needed. that would mean that the physiology od the pancreas and the liver (Glucogon) would also be altered.
 Hope this helps. Making suppositions is interesting


---------- FOLLOW-UP ----------

QUESTION: My thoughts were that blood sugar would be high because there is not enough insulin to move it across. So therefore I believe it would stay the same or go up if prolonged. Am I correct by my thinking? Also could you tell me how glucose plays in the formation of ATP? Thank you

Without the carrier molecule the glucose level would certainly. You asked what would happen if glucose moved across by simple diffusion and I believe I answered that. With respect to the formation of ATP. During complete Glucose metabolism one molecule of Glucose yields 36 molecules of ATP


All Answers

Answers by Expert:

Ask Experts


Walter Hintz


Science teacher for over 50 years. MSc. in biology. I can answer questions in general biology, zoology, botany, anatomy and physiology and biochemistry.


I have a MSc in biology and have been a science teacher for over 50 years. At present I am a faculty member at a college and a science consultant at seven catholic schools.

The Ohio journal of Science
Momentum-The Journal of the Catholic Education Association

©2017 All rights reserved.