POST LAB

• Factors that influence the rate of diffusion: Temperature, concentration gradient, surface area, and diffusion distance, mass of diffusing substance - ALL DIRECTLY PROPORTIONAL except for mass of diffusing substance and diffusion distance (INDIRECTLY PROPORTIONAL)
• Diffusion-increased rate of diffusion  with increase temperature

  
• 0.1% saline solution

  • is HYPOTONIC, meaning cells would inflate thus the potato would INCREASE IN SIZE.
  • In animal cells, it may cause cell lysis or bursting, to prevent this the cell has specialized organelles called contractile vacuoles.
• 0.9% saline solution

  • is ISOTONIC, meaning cells would stay the same because the environment is in an equilibrium
  • “ISO” means the same
• 25% saline solution

  • is HYPERTONIC, meaning cells would SHRINK
  • In blood cells, this causes crenation or the collapsing of the structure of the cell due to more solute outside of the cell
• Active Transport

  •Energy is required for carrier proteins to move solutes against a concentration gradient

  •Transport maximum and saturation

  •Two sources of cellular energy:

  -Hydrolysis of ATP (Primary Active Transport)

  -Energy stored in an iconic concentration gradient (secondary active transport)
• Dialysis results:

  Heller’s Test - NEGATIVE

  Fehling’s Test - NEGATIVE

  Test for salts - POSITIVE
• Why salt is the only molecule detected on the dialysate?

  • This is because the semi-permeable membrane only allows the passing through of smaller particles.

  Salt is a compound of Sodium and Chlorine while Sugar contains a number of Carbon, Hydrogen and Oxygen atoms which would make Sugar the larger particle. Proteins on the other hand are more complex molecules than the previously mentioned molecules