active transport

• does active transport require energy?

  yes
• active transport?

  movement of molecules from a region of low concentration to a region of high concentration, across a membrane
• what does active transport require?

  energy and carrier proteins
• process of active transport?

  the molecule or ion binds to receptors on the carrier protein, inside the cell ATP binds to the carrier protein and is hydrolysed into ADP and phosphate, binding of phosphate to the carrier protein changes the shape, opening the carrier protein to the inside of the cell, the molecule or ion is released, the phosphate molecule is released and reforms ATP, the carrier protein returns to its original shape
• active transport, type C?

  C

  
• bulk transport is a form of active transport
• what are the two types of bulk transport?

  Endocytosis and exocytosis.
• endocytosis?

  bulk transport of substances into the cell
• exocytosis?

  bulk transport of substances out the cell
• what happens in endocytosis?

  when in contact with the material, the membrane invaginates until a vesicle is formed
• what happens in exocytosis?

  vesicles fuse with the cell surface membrane, the contents are released out of the cell
• does endocytosis require energy?

  yes
• does exocytosis require energy?

  yes
• endocytosis: type C?

  C

  
• exocytosis: type C?

  C