5.3

Question 1

Differentiate between active transport and diffusion.

Answer 1

Active transport requires energy, either directly or indirectly to fuel active transport. Moves substances from low to high concentration. Requires the use of highly selective carrier proteins. Diffusion is the movement of molecules from high concentration to low concentration.

Question 2

Relate the concentration gradient to active transport

Answer 2

Molecules move from low->high concentration using ATP AGAINST THE CONCENTRATION GRADIENT

Question 3

Differentiate between uniporters, symporters, and antiporters in active transport

Answer 3

o Uniporters- move one molecule at a time
o Symporters- move 2 molecules in the SAME direction (uses one molecule to move the other)
o Antiporters= move 2 molecules in OPPOSITE directions
 All of these can be terms used to describe facilitated diffusion carriers

Question 4

Describe the function of the Na+/K+ pump.

Answer 4

Uses an antiporter to move 3 Na+ out of the cell and 2 K+ into the cell (both go against concentration gradients and use ATP for active transport)

Question 5

Explain the energetics of coupled transport.

Answer 5

Uses the energy that is released when a molecule moves by diffusion to provide energy for active transport of a different molecule (2 molecules are linked through the transfer of energy from one to help active transport of another). uses symporter

Question 6

Distinguish between endocytosis and exocytosis.

Answer 6

o Endocytosis= cell bringing substances/particles IN the cell
o Exocytosis= cell releasing contents outside the cell

Question 7

Differentiate between phagocytosis, pinocytosis, and receptor-mediated endocytosis

Answer 7

o Phagocytosis= cell takes IN particular MATTER
o Pinocytosis= cell takes IN only FLUID
o receptor-mediated endocytosis= specific molecules are taken in after they bind to receptor. receptor proteins have to form clathrin coated pits