Cell Transport and Homeostasis

Which type of molecule goes through the membrane easily

Non-polar molecules

Which type of molecule needs additional help to get through the membrane

Polar molecules

Passive Transport

• Something moves from an area of high concentration to an area of low concentration

• Diffusion and Osmosis

Diffusion

• the movement of molecules from an area of high concentration to low concentration

• Requires NO energy but the rate of diffusion is affected by temperature and concentration

• Diffusion happens due to molecules spontaneously spreading out and randomly moving according to their kinetic energy.

• Will result in equilibrium

Osmosis

• Osmosis is the spontaneous net movement or diffusion of solvent molecules through a selectively permeable membrane from a region of high-water potential to a region of low water potential

• The movement of water from an area of high concentration to low concentration

• Specifically, this is ONLY the movement of water

• BUT, the direction of osmosis is therefore determined by the SOLUTES on either side of the cell membrane

Define the tonics

• Hypertonic: More solute

• Hypotonic: Less solute

• Isotonic: Equal solute

Transport Proteins

• Pumps and proteins move against concentration gradient

• Solute binds

• ATP becomes ADP and phosphate attaches to protein, pushing the solute out of the cell

• Another solute binds to it and the protein changes shape again, releasing the phosphate and the second solute

• (Sodium (1st) and Potassium (2nd) pumps)

Endocytosis and Exocytosis

• Formation of vesicles to move macromolecules into or out of the cell

• Phagocytosis - food vacuole

• Pinocytosis - drink

Homeo

• unchanging

Stasis

• unchanging

Kinds of proteins

• Lipases - fats

• Amylase - starches

• Maltase - Saliva (breaks maltose into glucose)

• Trypsin - break protein into amino acids

Enzyme conditions

• based on temperature and ph

What does temperature do to blood vessels

• warm (dilate)

• cold(contract)