plus post lecture

Question 1

what is tonicity

Answer 1

• solution outside of a cell can change a cell’s volume by affecting osmosis
• relates to osmolarity
  
  • osmolarity: the solution’s total solute concentration

Question 2

what is osmotic pressure

Answer 2

• the pressure that prevents water from crossing a membrane
• hydrostatic pressure:
  
  • the pressure of the cytoplasm pushing against the cell membrane
• hypertonic: high concentration solute
• hypotonic: low concentration of solute
• isotonic: same osmotic pressure

Question 3

how to maintain osmotic balance

Answer 3

• extrusion: vacuoles in paramecium collect and remove water
• isosmotic: body fluids that maintain the same osmotic pressure inside and outside the cells
• turgor: the internal hydrostatic pressure in plant cells that pushes the plasma membrane against the interior of the cell wall