Cell Membrane: Exchange And Transport

Question 1

Plasma membrane

Answer 1

Fluid-mosaic model, 75% phospholipid, 20% cholesterol, proteins, cell membrane receptors

Question 2

Diffusion

Answer 2

Partially permeable

Question 3

Ficks law

Answer 3

Relationship between factors that affect diffusion of a gas’s across a membrane. V’gas = D x (A/T) x change in P

Question 5

Osmosis

Answer 5

High to low water potential across a partially permeable membrane.

Question 6

Turgor pressure

Answer 6

High water potential, absorb water, increase hydrostatic pressure inside cell, the cytoplasm and vacuole push the membrane against the cell wall, causing cell to swell.

Question 7

Plasmolysis

Answer 7

Low water potential, loose water, hydrostatic pressure will fall. Cell wall may burst

Question 8

Phagocytosis

Answer 8

Food material becomes encased in a phagosome. Lysosome fuses with it and empty’s enzymes onto the food. Moved towards the cell membrane and indigested particles are released

Question 9

Pinocytosis

Answer 9

Allows uptake of small particles that are suspended in extracellularfluid the pirocytic vesicles fuse with lysosomes to hydrolyse the particles

Question 10

Exocytosis

Answer 10

For egestion of undigested particles, secretion of extra cellular substances