Essential Standard Bio.1.2 Analyze the cell as a living system. Cell Transport Essential Standard Bio.1.2 Analyze the cell as a living system.

Cell Transport Movement of materials across cell membrane Passive Transport Active Transport

Passive Transport Movement of substances across membrane without input of energy until equilibrium is reached With concentration gradient; high to low concentration Diffusion Osmosis Facilitated Diffusion Ion Channels

Active Transport Movement of substances across membrane requiring input of energy Against concentration gradient; low to high concentration Protein Pumps Endocytosis Exocytosis

Passive Transport - Diffusion Movement of molecules Molecules are in constant motion Moves with the concentration gradient Rate of diffusion depends on Size of molecule Type of molecule

Passive Transport - Osmosis Diffusion of water Direction of osmosis depends on concentration of solutes on both sides of membrane Hypotonic solution Cytolysis (cell swells) Hypertonic solution Plasmolysis (cell bursts) Isotonic solution

Osmosis Problems A cell which is 80% water is placed into a solution of 10% sucrose. What is the direction of the water movement?

Osmosis Problems A cell has 45% sodium concentration and is placed in a solution of 55% water concentration. What is the direction of the water movement?

Passive Transport – Facilitated Diffusion Diffusion of larger molecules Use carrier proteins (integral) No energy required

Passive Transport – Ion Channels Regulate flow of ions across membrane Ion-specific! Ions requiring ion channels: Na+, K+, Ca+, Cl-

Active Transport – Protein Pumps Carrier protein that transports molecules against concentration gradient

Active Transport - Endocytosis Large particles are engulfed into the cell Pinocytosis – “cell drinking” Phagocytosis – “cell eating”

Active Transport – Exocytosis Large particles exit the cell