Membrane Structure and Transport

Question 1

phospholipid

Answer 1

hydrophilic phosphate head and a hydrophobic phosphate tail

Question 2

hypertonic

Answer 2

not enough liquid entering the cell, causes shriveled cells and dehydration

Question 3

isotonic

Answer 3

balance between liquid entering the cell and liquid exiting the cell

Question 4

hypotonic

Answer 4

too much liquid entering the cell, causes the cell to lyse

Question 5

simple diffusion

Answer 5

occurs naturally when there is a net charge across the membrane, always with the concentration gradient

Question 6

facilitated diffusion

Answer 6

uses channel proteins to allow molecules that can’t otherwise cross the hydrophobic fatty acid tails to move through the membrane, always with the concentration gradient

Question 7

primary active transport

Answer 7

channel proteins accept molecules from within the cell and use ATP to turn around and push the molecules out of the cell. then they accept new molecules and repeat the process to deposit these within the cell. can be with or against the concentration gradient

Question 8

secondary active transport

Answer 8

uses cotransporter proteins (powered by the difference in net charge across the cell membrane) to move molecules into and out of the cell. these spin like revolving doors to push proteins across the membrane. can be with or against the gradient