Cells - Active Cell Transport Notes

Active transport moves against the concentration gradient

Cells use ATP for active transport

Transport molecules move solute molecules across the membrane

Proteins pumps often move ions like @@calcium, potassium, and sodium@@ which normally can’t pass through the membrane

Protein pumps

==1) Solute attaches to the protein==

==2) ATP phosphorylates the protein==

==3) The protein changes shape and the solute is released on the other side of the membrane==

==4) The phosphate group detaches, and the protein returns to its original shape for a new round==

%%Active transport allows a cell to maintain concentrations of small molecules that are different from the concentration of its surroundings%%

%%An animal cell has a higher concentration of potassium ions (K+) and a lower concentration of sodium ions (Na+) than the solution outside the cell%%

%%Nerve signals depend on these concentration differences%%

%%The sodium-potassium pump helps cells maintain these steep gradients by shuttling Na+ and K+ across the membrane%%

When we cry, cells in our tear glands use exocytosis to export a salty solution containing proteins