Co-transport

Question 1

How does glucose and amino acids move into the small intestine

Answer 1

Moved into the small intestine by co-transport

Question 2

Role of sodium ions

Answer 2

NA+ are actively transported out of epithelial cells lining of the ileum into the blood by sodium potassium pump. This creates a concentration gradient of sodium in the lumen. As a result sodium ions and glucose/amino acids move by facilitated diffusion into the epithelial cell from the lumen via co-transporter protein. So glucose moves out of the cell into the blood by facilitated diffusion through a protein channel

Question 3

Importance of sodium ions

Answer 3

No NA+= glucose/amino acids absorbed into blood less efficiently
Na+ draws the glucose/amino acids into the epithelial cell by facilitated diffusion —–> no Na+ means that no concentration gradient of sodium ions to move these molecules in.
So no glucose absorbed= no glycolysis so no energy for muscle contraction or other metabolic processes such as respiration

Also no amino acids absorbed means that we wouldn’t be able to make proteins and therefore we have less efficient enzymes. has knock on effect on digestive system which hydrolyse molecules into smaller digestible ones. e.g.

Lipids——> fatty acid and glycerol