Getting Into and Out of Cells Cell Transport

Types of Cell Transport Passive Transport - no cellular energy required to occur - goes with the concentration gradient - diffusion - facilitated diffusion - osmosis Active Transport - requires cellular energy to occur - goes against the concentration gradient - Endocytosis/Exocytosis - Sodium Potassium Pump

Concentration Gradient The concentration gradient is the distribution of particles across space from high to low concentration

Passive Transport Energy for passive transport comes from the molecules themselves In passive transport, molecules move with the concentration gradient - move from high concentration to low concentration

Diffusion Primary means of cell transport - molecules move from high to low concentration - movement continues with the gradient until the molecules are evenly distributed - equilibrium is achieved

Facilitated Diffusion Particles move with the concentration gradient across a transport protein in the membrane - ions, sugar and amino acids all move into and out of cells by facilitated diffusion

Osmosis The diffusion of water across a selectively permeable membrane - water moves from where there is more water to where there is less water - water moves toward higher conc. of dissolved material - solute

Three osmotic environments Hypotonic environment Little(below) solute/lots of water What happens when you place cells in an environment that is hypotonic to it? Hmm Animal Cell Plant Cell

Hypotonic Environment Animal Cell Plant Cell Before Water Moves In After burst turgid

2 nd type of Environment Hypertonic Lots of solute/little water What happens when you place a cell in an environment that is hypertonic to it? hmm

Hypertonic environment Animal Cell Plant Cell Before Water Moves Out shrinks plasmolyze

3 rd Environment Isotonic Environment Equal amounts of solute and water What happens to a cell in an isotonic environment? hmm

Isotonic Environment Animal Before Plant Water Moves In and Out at an equal rate No Change After No Change