#9: Membrane Transport

Question 1

Concentration Gradient

Answer 1

Describes concentration difference of substance in 2 regions

Short form: [ ]

Question 2

Passive Transport

Answer 2

Uses no energy

Move molecules randomly

Moves from high concentration to low

Question 3

Diffusion

Answer 3

Movement of molecules from high concentration to low

Passive

Only small, uncharged particles can diffuse through membrane
Continues until molecules evenly spaced (equilibrium)

Question 4

Facilitated Diffusion

Answer 4

Uses carrier protein to move large molecules across membrane

Movement of molecules from high concentration to low

Passive

Question 5

Osmosis

Answer 5

Movement of water

Uses aquaporins (transport protein) to move polar substance across bilayer

3 terms to describe water relationship between cell and external environment: isotonic, hypotonic, hypertonic

Question 6

Isotonic

Answer 6

[solute] inside cell is SAME AS [solute] outside

Amount of water entering same as amount leaving

Question 7

Hypotonic

Answer 7

[solute] inside cell MORE THAN [solute] outside

Water moves from environment into cell

Question 8

Hypertonic

Answer 8

[solute] inside cell LESS THAN [solute] outside

Water moves out of cell into surrounding environment

Question 9

Active Transport

Answer 9

Move molecules specifically

Requires energy

Question 10

Protein Pumps

Answer 10

Uses carrier proteins to move molecules against [ ] gradient, which requires energy

ATP molecules provide proteins with energy it needs to drive active transport

Ex: Na/K pump- cells maintain high amounts of potassium inside cell and low amounts of sodium outside

Question 11

Endocytosis

Answer 11

Used to move large molecules INTO cell

Requires energy

Used to love molecules with or against [] gradient

3 Types: pinocytosis, phagocytosis, receptor-assisted endocytosis

Question 12

Pinocytosis

Answer 12

Moves small particles of extracellular fluid and dissolved particles into cell

Question 13

Phagocytosis

Answer 13

Moves large droplets of extracellular fluid along with large particles in cell

Question 14

Receptor-Assisted Endocytosis

Answer 14

Specific molecules attract protein receptors on membrane which triggers intake of molecules via endocytosis

Protein and molecules fit like lock and key

Question 15

Exocytosis

Answer 15

Used to move large molecules OUT of cell

Requires energy

Used to move molecules with or against [] gradient