1.5 Plasma Membrane

Question 1

Active transport

Answer 1

• does use energy in the transport process (goes up)
  
  • endocytosis
    
    • use of protein pumps/ channels
  • exocytosis

Question 2

Passive transport

Answer 2

• goes not use energy in the transport process (goes down)
  
  • simple diffusion
  • facilitated diffusion
  • Osmosis

Question 3

Simple diffusion

Answer 3

the passive movement of a solute from a region of higher concentration to a region of lower concentration. (E.g. water, oxygen, carbon dioxide)

Question 4

Facilitated diffusion

Answer 4

movement goes down the concentrated gradient but requires the use of a channel protein (e.g. glucose and amino acid transport, gas transport, and ion transport)

Question 5

Osmosis

Answer 5

The net diffusion of water molecules across a semi-permeable membrane

Moves across the cell membrane from a region of low solute concentration to a region of high solute concentration

Question 6

Active transport

Answer 6

requires input of energy by the cell, involves a carrier proteins attached to a source of energy (ATP) and is against a concentration gradient (lower to a higher region)

Question 7

Distinguish between hypotonic, hypertonic and isotonic solutions

Answer 7

hypertonic solutions is when the cell shrinks due to the net movement of water outside the cell, while hypotonic solution is when the cell swells up and bursts sue to the net movement of water inside the cell. Isotonic solution remains the same because there is no net movement of water.

Question 8

How hypotonic solutions affect plant and animal cells

Answer 8

Plant Cells: water moves into the plant cell by osmosis, causing the cell to swell.

Animal Cells: Can burst if too much water flows in.

Question 9

How hypertonic solutions affect plant and animal cells

Answer 9

Plant Cells: water moves out of the plant cell by osmosis, causing the cell to lose water and shrink.

Animal Cells: water moves out of the animal cell, causing it to shrink or undergo crenation. This can disrupt normal cellular functions and lead to dehydration and potential cell death.

Question 10

Explain how isotonic solutions affect plant and animal cells.

Answer 10

Both Plant and Animal Cells: Stay the same size because water flows in and out equally, keeping them stable.

Question 11

Exocytosis

Answer 11

is a process in which substances exit the cell via the plasma membrane

is a process in which substances exit the cell via the plasma membrane

Question 12

Endocytosis

Answer 12

is a process in which a substance enters the cell

built transport of molecules or large substances into the cells is endocytosis