Ion Transport And Generayiom Of Ion Gradients Flashcards
How is the electrochemical gradient that determines transport of solute is formed
For a solute carrying a net charge, the concentration gradient and the electrical potential difference combine to form it
Why does the electrochemical gradient form
Due to the net positive charge outside the cell and net negative charge inside the cell
When is a membrane potential created
When there is a difference in electrical charge on the two sides of the membrane
How do ion pumps establish and maintain ion gradients
Use energy from hydrolysis of ATP
What’s the sodium potassium pump
Actively transports sodium ions out of the cell and potassium ions in the cell
What’s step 1+2 of sodium potassium pump
1- the pump has high affinity for sodium ions inside the cell
2-binding occurs name the pump is phosphorylated by ATP
What’s step 3+4 of sodium potassium pump
3-the conformation of the protein changes and the affinity for sodium ions decreases. Meaning sodium ions are released outside the cell
4-potassium ions bind outside the cell
What’s stage 5+6 of sodium potassium pump
5- dephosphorylation occurs and the conformation of the protein changes
6-potassium ions are taken into cell and then affinity returns to start
What happens for each ATP hydrolysed
Three sodium ions are transported out of the cell and two potassium ions are transported into the cell. Establishing both chemical and electrical gradient
Where is the sodium potassium pump found
Most animal cells accounting for high proportion of the basal metabolic rate
What does the sodium potassium pump do in the small intestine
Drives the active transport of glucose
What does the sodium potassium pump do in intestinal epithelial cells
Generates a sodium ion gradient across the plasma membrane
What’s does the glucose transporter do
Transports sodium ions and glucose at the same time and in the same direction
How do sodium ions enter the cell in glucose symport
Down their concentration gradient
How does the transport of glucose pump glucose into the cell
Against the concentration gradient
