U1 - Ion transport and generation of ion gradients Flashcards
What is combined to form the electrochemical gradient?
concentration gradient
electrical potential difference
When is a membrane potential created
It is created when there is a difference in electrical charge on two sides of the membrane
How do ions pumps such as the sodium-potassium pump establish ion gradients
It uses energy from the breakdown of ATP to establish and maintain ion gradients.
how does the electrochemical gradient determine a solutes transport?
The solute carries a net charge so the electrochemical gradient determines the transport of the solute.
How does the sodium potassium pump transport ions?
It transports ions against a steep concentration gradient using energy directly from ATP hydrolysis.
It actively transports ______ out of the cell and _____ in to the cell
Sodium
Potassium
From the breakdown of 1 ATP how many sodium and potassium can be transported out
Three sodium
Two potassium
What establishes both concentration gradients and an electrical gradient
The transportation of three sodium out and two potassium in.
Process of Sodium-Potassium pump
The pump has high affinity for sodium ions inside the cell and binding occurs. Phosphorylation by ATP provides energy. A conformational change occurs and the affinity for sodium decreases realeasing them outside the cell. Potassium ions bind outside the cell and dephosphorylation occurs. this brings about a conformational change and the potassiums are released into the cell. the affinity returns to the start.
What does the sodium potassium account for in animal cells?
A high proportion of basal metabolic rate.
What does the sodium potassium pump do in the small intestine
The sodium gradient created by the pump drives the active transport of glucose.
In intestinal epithelial cells the sodium potassium pump generates a sodium ion gradient across the plasma membrane
What is responsible for the transport of glucose with sodium
The glucose transporter responsible for this glucose symport transports sodium ions and glucose at the same time and in the same direction.
direction of transport in the small intestine
Sodium ions enter the cell down their concentration gradients and the simultaneous transport of glucose into the cell AGAINST its concentration gradient.
