After sodium ions are actively transported out of the epithelial cells in the ileum into the blood via the sodium potassium pump, via what process do sodium ions get into the epithelial cells again by the sodium glucose co-transporter protein? Is it diffusion or active transport?
Are the sodium ions moving along or against their concentration gradient? If along, it'll be diffusion, if it's against it'll be active transport.
This is the whole process:
The sodium ions are actively transported out of the ileum via the sodium potassium ion pump and the sodium ions move up their concentration gradient (basically against it) and enter the blood
The removal of sodium ions from the ileum/epithelial cells results in the concentration of sodium ions being higher in the lumen compared to the ileum so a sodium ion concentration gradient is established
The sodium ions therefore move down their concentration gradient and move from the lumen to the ileum via facilitated diffusion, this happens through the sodium-glucose sumport (co-transporter) proteins and so, as the sodium ions move down their concentrations gradient, the glucose molecules enter the ileum with them
This then results in a higher concentration of glucose in the ileum compared to the blood so a glucose concentration gradient is now established
So, glucose moves down its concentration gradient and diffuses through the phospholipid bilayer from the ileum and into the blood where it is then transported to the cells for various processes (mainly respiration) or if there is too much, then it is stored as glycogen