Unit 1.3b Flashcards
What makes the electrochemical gradient?
concentration gradient + electrical potential difference
What determines the transport of a solute?
The electrochemical gradient
What is the membrane potential?
When two sides of the membrane have opposing charges
What is the net charge of the inside of the membrane?
Negative
What is the net charge of the outside of the membrane?
Positive
What does the sodium-potassium pump do?
Transports 2 sodium ions out if the cell and 2 potassium ions in against their concentration gradients
What is stage 1 of the sodium-potassium pump?
High affinity for sodium ions inside the cell
What is stage 2 of the sodium-potassium pump?
Sodium ions bind, pump is phosphorylated by ATP.
What is Stage 3 of the sodium-potassium pump?
proteins conformation changes, affinity for sodium decreases, sodium released outside of cell
What is Stage 4 of the sodium-potassium pump?
Potassium ions bind outside of cell
What is stage 5 of the sodium-potassium pump?
Dephosphorylation occurs and conformation
What is stage 6 of the sodium-potassium pump?
Potassium taken into cell and affinity goes back to beginning
Where are sodium-potassium pumps found and what is their main function?
In animal cells and assists the basal metabolic rate in organisms.
Why are sodium-potassium pumps found in the intestines?
To transport glucose into the intestine
How is glucose transported into the intestines?
By a sodium ion gradient across the plasma membrane
