transport across the cell membrane 1.2

Question 1

the cell membrane is ________ permeable

Answer 1

selectively

Question 2

how do large molecules pass through selective permeable membrane

Answer 2

with the help of proteins

Question 3

diffusion

Answer 3

the movement of molecules from an area of high concentration gradient to an area of low concentration gradient until evenly spread

Question 4

passive transport

Answer 4

• movement of molecules down the concentration gradient.

- this doesn’t require energy

Question 5

what diffuses into the body

Answer 5

dissolved food and dissolved oxygen moves into the cell from a high to a low concentration

Question 6

what diffuses out of our body

Answer 6

carbon dioxide diffuses out of the cell from a low to high concentration

Question 7

osmosis

Answer 7

the movement of water molecules from a region of high water concentration to a region of low water concentration through a selective permeable membrane

Question 8

what happens when plant cells are placed in a solution of equal water concentration (dilute sugar solution)

Answer 8

there is no change because there is no new movement of water molecules in any direction

Question 9

what happens when plants cells are placed in a solution with a higher water concentration (pure water)

Answer 9

water moves into the cell and the cell becomes turgid

Question 10

what happens when plant cells are placed a solution with a lower water concentration (concentration sugar solution)

Answer 10

water moves out of the cell and the cell becomes plasmolysed

Question 11

calculate % change

Answer 11

final-start/start x 100

Question 12

what happens when animal cells are placed in a solution with a higher water concentration (distilled water)

Answer 12

water moves into the cell and the cell bursts

Question 13

what happens when animal cells are placed in a solution with equal water concentration (dilute salt solution)

Answer 13

there is no new movement of water molecules so the cell remains unchanged

Question 14

what happens when an animal cell is placed in a solution with a lower water concentration (concentrated salt solution)

Answer 14

water moves out of the cell and the cell shrinks

Question 15

active transport

Answer 15

• movement of ions or molecules across the cell membrane from a region of low concentration to a region of high concentration against the concentration gradient
• requires energy released by respiration