Active transport

Question 1

what is active transport?

Answer 1

when a cell uses energy to cross a a membrane; moving cell against concentration gradient

Question 2

what are the two major means of active membrane transport?

Answer 2

active and vesicular

Question 3

what is primary active transport?

Answer 3

Active transport in which ATP is hydrolyzed, yielding the energy required to transport an ion or molecule against its concentration gradient.

Question 4

what causes an electrochemical gradient?

Answer 4

what causes an electrochemical gradient?

Question 5

why is it important for there to be an ionic concentration difference?

Answer 5

for muscles and nerve cells to function normally and for all body cells to maintain normal fluid volume

Question 6

How does secondary transport work?

Answer 6

by moving sodium ion across plasma membrane against its concentration gradient the pumps store energy and other substances can be dragged along the membrane like sugars or amino acids

Question 7

What is a symport system?

Answer 7

two substances are moved across a membrane in the same direction

Question 8

what is an antiport system?

Answer 8

two substances are moved across a membrane in opposite directions

Question 9

what is vesicular transport?

Answer 9

flu ds containing large particles and macromolecules are transported across cellular membranes inside bubble-like, membranous sacs called vesicles

Question 10

what is transcytosis?

Answer 10

moves substances into, across, and then
out of the cell.

• common in blood vessels to interstitial fluid

Question 11

what can vesicular traffickijng be compared to?

Answer 11

FedEx b/c its moves substances from one organelle in the cell to another. They need energy like vans from ATP or GTP

Question 12

what is phagocytosis

Answer 12

cell engulf large solid material and forms a phagosome which will fuse with lysosome for digestion

Question 13

what is pinocytosis

Answer 13

The cell gulps a drop of
extracellular fluid containing
solutes into tiny vesicles. No
receptors are used, so the
process is nonspecific

Question 14

what is receptor mediated endocytosis?

Answer 14

-selective mechanism allowing for it to concentrate materials
- only takes small amounts
- hormones, enzyme, insulin etc.. use this route
-flu, viruses

Question 15

what is exocytosis?

Answer 15

• Secretion or ejection of substances from a cell.
• The substance is enclosed in a membranous
  vesicle, which fuses with the plasma membrane (t- snares and its V snares)
  and ruptures, releasing the substance to the
  exterior.

-secretion of mucus, neurotransmitter, hormones

Question 16

what is the concentration of potassium inside and outside of the cell?

Answer 16

5 millimolar pushing it in 150 millimolar

Question 17

what is the counter ion? why?

Answer 17

chloride to balance the outside of the cell because of the positive potassium ions acting as a buffer

Question 18

what happens as na diffuse back across the membrane

Answer 18

it uses energy left over to push other nutrient against it own gradient glucose back into the cell

Question 19

potassium has a larger leakage current leaving the cell then Sodium. T or F

Answer 19

True

Question 20

what is the membrane voltage after the ion have returned to it starting position

Answer 20

-70mV inside is negative relative to outside of cell

Question 21

what is the limitation of facilitated diffusion

Answer 21

carrier saturation

Question 22

what is the most well known substance that is transported by carrier mediated facilitated diffusion

Answer 22

glucose

Question 23

what is it called when the protein changes it shape or opening

Answer 23

confirmational change

Question 24

what takes up most of ATP consumption in neurons

Answer 24

Active transport

Question 25

why does potassium come into the cell in the first place?

Answer 25

negative charge established in the inner membrane face in it’s lasts step

Question 26

what is the membrane potential perfectly balanced for k+ when does it go back to its resting potential?

Answer 26

-90mV and returns back when sodium enters the membrane again brining it back to -70mV